United States
Environmental Protection
Agency
                                  EPA/600/R-14/413b
                                  Revised September 2015
                                  www2.epa.gov/water-research
        Storm Water Management Model
        User's Manual Version 5.1
                           ITV

 Office of Research and Development
 Water Supply and Water Resources Division

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                                      EPA-600/R-14/413b
                                   Revisied September 2015
Storm Water Management Model
User's Manual Version 5.1
                   by
               Lewis A. Rossman
          Environmental Scientist, Emeritus
        U.S. Environmental Protection Agnecy
             National Risk Management
          Laboratory Office of Research and
          Development U.S. Environmental
          Protection Agency 26 Martin Luther
           King Drive Cincinnati, OH 45268
                 September 2015

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                        ACKNOWLEDGEMENTS
This manual was prepared by Lewis  A. Rossman, Environmental Scientist Emeritus, U.S.
Environmental  Protection  Agency, Office of Research  and Development,  National Risk
Management Research Laboratory.

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                                   DISCLAIMER
The information in this document has been funded wholly or in part by the U.S. Environmental
Protection Agency (EPA).  It has been subjected to the Agency's peer and administrative review,
and has been approved for publication as an EPA document. Note that  approval does not signify
that the  contents necessarily reflect the  views  of  the  Agency. Mention of trade  names  or
commercial products does not constitute endorsement or recommendation for use.

NOTICE: This report was prepared as an account of work sponsored by an agency of the United
States Government.  Neither the United  States Government, nor any agency thereof, nor any of
their employees, nor any of their contractors, subcontractors,  or their employees, make any
warranty, express or implied,  or  assume  any legal  liability or  responsibility  for the accuracy,
completeness, or usefulness of  any information, apparatus, product,  or process disclosed,  or
represent that its use would not infringe privately owned rights. Reference  herein to any specific
commercial product,  process, or service by trade name, trademark, manufacturer, or otherwise,
does not necessarily constitute or imply its endorsement, recommendation, or favoring by the
United States Government, any agency thereof, or any of their contractors or subcontractors. The
views and opinions expressed herein do not necessarily state or reflect those of the United States
Government, any agency thereof, or any of their contractors.

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                                CONTENTS





ACKNOWLEDGEMENTS	II





DISCLAIMER	Ill





CHAPTER 1 - INTRODUCTION	12



1.1     What is SWMM	12



1.2     Modeling Capabilities	13



1.3     Typical Applications of SWMM	14



1.4     Installing EPA SWMM	14



1.5     Steps in Using SWMM	15



1.6     About This Manual	16





CHAPTER 2 - QUICK START TUTORIAL	18




2.1     Example Study Area	18



2.2     Project Setup	18



2.3     Drawing Objects	21



2.4     Setting Object Properties	24



2.5     Running a Simulation	28



2.6     Simulating Water Quality	38



2.7     Running a Continuous Simulation	42





CHAPTER 3 - SWMM'S CONCEPTUAL MODEL	46



3.1     Introduction	46



3.2     Visual Objects	46



3.3     Non-Visual Objects	57



3.4     Computational Methods	72





CHAPTER 4 - SWMM'S MAIN WINDOW	80




4.1     Overview	80



4.2     Main Menu	81




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4.3     Toolbars	84



4.4     Status Bar	86



4.5     Study Area Map	87



4.6     Project Browser	88



4.7     Map Browser	89



4.8     Property Editor	91



4.9     Setting Program Preferences	92





CHAPTER 5 -WORKING WITH PROJECTS	94




5.1     Creating a New Project	94



5.2     Opening an Existing Project	94



5.3     Saving a Project	94



5.4     Setting Project Defaults	95



5.5     Measurement Units	97



5.6     Link Offset Conventions	97



5.7     Calibration Data	98



5.8     Viewing All Project Data	100





CHAPTER 6 -WORKING WITH OBJECTS	101




6.1     Types of Objects	101



6.2     Adding Objects	101



6.3     Selecting and Moving Objects	102



6.4     Editing Objects	103



6.5     Converting an Object	104



6.6     Copying and Pasting Objects	104



6.7     Shaping and Reversing Links	104



6.8     Shaping a Subcatchment	105



6.9     Deleting an Object	105



6.10   Editing or Deleting a Group of Objects	105

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CHAPTER 7 -WORKING WITH THE MAP	108




7.1     Selecting a MapTheme	108



7.2     Setting the Map's Dimensions	108



7.3     Utilizing a Backdrop Image	109



7.4     Measuring Distances	113



7.5     Zooming the Map	113



7.6     Panning the Map	114



7.7     Viewing at Full Extent	114



7.8     Finding an Object	114



7.9     Submitting a Map Query	115



7.10    Using the Map Legends	116



7.11    Using the Overview Map	118



7.12    Setting Map Display Options	118



7.13    Exporting the Map	122





CHAPTER 8 - RUNNING A SIMULATION	124



8.1     Setting Simulation Options	124



8.2     Setting Reporting Options	131



8.3     Starting a Simulation	132



8.4     Troubleshooting Results	133





CHAPTER 9 - VIEWING RESULTS	136




9.1     Viewing a Status Report	136



9.2     Viewing Summary Results	136



9.3     Time Series Results	140



9.4     Viewing Results on the Map	141



9.5     Viewing Results with a Graph	142



9.6     Customizing a Graph's Appearance	148



9.7     Viewing Results with a Table	153





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9.8     Viewing a Statistics Report	156





CHAPTER 10 - PRINTING AND COPYING	160




10.1    Selecting a Printer	160



10.2    Setting the Page Format	161



10.3    Print Preview	162



10.4    Printing the Current View	162



10.5    Copying to the Clipboard orto a File	162





CHAPTER 11 - FILES USED BY SWMM	164




11.1    Project Files	164



11.2    Report and Output Files	164



11.3    Rainfall Files	165



11.4    Climate Files	165



11.5    Calibration Files	166



11.6    Time Series Files	167



11.7    Interface Files	168





CHAPTER 12 - USING ADD-IN TOOLS	173




12.1    What Are Add-In Tools	173



12.2    Configuring Add-In  Tools	174





APPENDIX A - USEFUL TABLES	177




A.1     Units of Measurement	177



A.2    Soil Characteristics	178



A.3    NRCS Hydrologic Soil Group Definitions	179



A.4    SCS Curve Numbers	180



A.5    Depression Storage	181



A.6    Manning's n - Overland Flow	182



A.7    Manning's n - Closed Conduits	183



A.8    Manning's n -Open Channels	184



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A.9     Water Quality Characteristics of Urban Runoff	185



A.10   Culvert Code Numbers	186



A.11   Culvert Entrance Loss Coefficients	189



A.12   Standard Elliptical Pipe Sizes	190



A.13   Standard Arch Pipe Sizes	191





APPENDIX B - VISUAL OBJECT PROPERTIES	195




B.1     Rain Gage Properties	195



B.2     Subcatchment Properties	196



B.3     Junction Properties	198



B.4     Outfall Properties	199



B.5     Flow Divider Properties	200



B.6     Storage Unit Properties	202



B.7     Conduit Properties	204



B.8     Pump Properties	205



B.9     Orifice Properties	206



B.10   Weir Properties	207



B.11   Outlet Properties	208



B.12   Map Label Properties	209





APPENDIX C - SPECIALIZED PROPERTY EDITORS	210




C.1     Aquifer Editor	210



C.2     Climatology Editor	212



C.3     Control Rules Editor	220



C.4     Cross-Section Editor	225



C.5     Curve Editor	226



C.6     Groundwater Flow Editor	227



C.7     Groundwater Equation Editor	230



C.8     Infiltration Editor	231





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C.9     Inflows Editor	234



C.10    Initial Buildup Editor	239



C.11   Land Use Editor	240



C.12   Land Use Assignment Editor	244



C.13   LID Control Editor	245



C.14   LID Group Editor	251



C.15   LID Usage Editor	252



C.16   Pollutant Editor	254



C.17   Snow Pack Editor	256



C.18   Time Pattern Editor	260



C.19   Time Series Editor	261



C.20   Title/Notes Editor	263



C.21   Transect Editor	264



C.22   Treatment Editor	266



C.23   Unit Hydrograph Editor	268





APPENDIX D - COMMAND LINE SWMM	270





APPENDIX E - ERROR AND WARNING MESSAGES	343
                                         IX

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                             LIST OF FIGURES
FIGURE 2-1  EXAMPLE STUDY AREA	18
FIGURE 2-2  DEFAULT ID LABELING FOR TUTORIAL EXAMPLE	19
FIGURE 2-3  MAP OPTIONS DIALOG	21
FIGURE 2-4  SUBCATCHMENTS AND NODES FOR EXAMPLE STUDY AREA	22
FIGURE 2-5  PROPERTY EDITOR WINDOW	24
FIGURE 2-6  GROUP EDITOR DIALOG	25
FIGURE 2-7  TIME SERIES EDITOR	27
FIGURE 2-8  TITLE/NOTES EDITOR	28
FIGURE 2-9  SIMULATION OPTIONS DIALOG	29
FIGURE 2-10 PORTION OF A STATUS REPORT	30
FIGURE 2-11 NODE FLOODING SUMMARY TABLE	31
FIGURE 2-12 CONDUIT SURCHARGE SUMMARY TABLE	31
FIGURE 2-13 VIEWING COLOR-CODED RESULTS ON THE STUDY AREA MAP	32
FIGURE 2-14 TIME SERIES PLOT DIALOGS	34
FIGURE 2-15 TIME SERIES PLOT OF LINK FLOWS	34
FIGURE 2-16 PROFILE PLOT DIALOG	35
FIGURE 2-17 EXAMPLE PROFILE PLOT	36
FIGURE 2-18 DYNAMIC WAVE SIMULATION OPTIONS	37
FIGURE 2-19 POLLUTANT EDITOR DIALOG	39
FIGURE 2-20 LAND USE EDITOR DIALOG	39
FIGURE 2-21 DEFINING A TSS BUILDUP FUNCTION	40
FIGURE 2-22 LAND USE ASSIGNMENT DIALOG	41
FIGURE 2-23 RUNOFF TSS FROM SELECTED SUBCATCHMENTS	42
FIGURE 2-24 STATISTICS SELECTION DIALOG	44
FIGURE 2-25 EXAMPLE STATISTICS REPORT	45
FIGURE 3-1  PHYSICAL OBJECTS USED TO MODEL A DRAINAGE SYSTEM	47
FIGURE 3-2  CONCRETE Box CULVERT	53
FIGURE 3-3  AREAL DEPLETION CURVE FOR A NATURAL AREA	59
FIGURE 3-4  AN RDM UNIT HYDROGRAPH	61
FIGURE 3-5  EXAMPLE OF A NATURAL CHANNEL TRANSECT	62
FIGURE 3-6  ADJUSTMENT OF SUBCATCHMENT PARAMETERS AFTER LID PLACEMENT	71

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FIGURE 3-7 CONCEPTUAL VIEW OF SURFACE RUNOFF	73
FIGURE 3-8 TWO-ZONE GROUNDWATER MODEL	74
FIGURE 3-9 CONCEPTUAL DIAGRAM OF A BIO-RETENTION CELL LID	78
FIGURE 8-1 FLOW INSTABILITY INDEX FOR A FLOW HYDROGRAPH	135
FIGURE 11-1 COMBINING ROUTING INTERFACE FILES	171
                             LIST OF TABLES
TABLE 3-1 AVAILABLE CROSS SECTION SHAPES FOR CONDUITS	52
TABLE 3-2 AVAILABLE TYPES OF WEIRS	56
TABLE 9-1 TIME SERIES VARIABLES AVAILABLE FOR VIEWING	141
TABLE D-1 GEOMETRIC PARAMETERS OF CONDUIT CROSS SECTIONS	313
TABLE D-2 POLLUTANT BUILDUP FUNCTIONS (T is ANTECEDENT DRY DAYS)	326
TABLE D-3 POLLUTANT WASH OFF FUNCTIONS	327
                                       XI

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                       CHAPTER 1 -INTRODUCTION
1.1
What is SWMM
The EPA Storm Water Management Model (SWMM) is a dynamic rainfall-runoff simulation model
used for single event or long-term (continuous) simulation of runoff quantity and quality from
primarily urban areas. The runoff component of SWMM operates on a collection of subcatchment
areas that  receive  precipitation  and generate runoff and pollutant loads. The routing portion of
SWMM transports  this runoff through a system of pipes,  channels, storage/treatment devices,
pumps, and regulators. SWMM tracks the quantity and quality of runoff generated within each
subcatchment, and the flow rate, flow depth, and quality of water in each pipe and channel during
a simulation period comprised of multiple time steps.
                                 Wet Weather FUws
SWMM was first developed in 19711 and has undergone several major upgrades since then2. It
continues to be widely used throughout the world for planning, analysis and design related to
storm water runoff,  combined  sewers, sanitary sewers, and other drainage systems in urban
1  Metcalf & Eddy, Inc., University of Florida, Water Resources Engineers, Inc. "Storm Water
Management  Model,  Volume  I  - Final  Report", 11024DOC07/71,  Water Quality  Office,
Environmental Protection Agency, Washington, DC, July 1971.
2  Huber, W.C. and Dickinson, R.E., "Storm Water Management Model, Version 4: User's Manual,
EPA/600/3-88/001 a, Environmental Research Laboratory, U.S. Environmental Protection Agency,
Athens, GA, October 1992.
                                        12

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areas,  with many applications in non-urban areas as well. The current edition, Version 5, is a
complete re-write of the previous release.

Running  under Windows,  SWMM 5 provides an integrated environment for editing study area
input data, running hydrologic, hydraulic and water quality simulations, and viewing the results in
a variety of formats. These  include color-coded drainage area and  conveyance  system maps,
time series graphs and tables, profile plots, and statistical frequency analyses.

This latest re-write of SWMM was produced by the Water Supply and Water Resources Division
of the U.S. Environmental  Protection Agency's National Risk  Management Research Laboratory
with assistance from the consulting firm of CDM-Smith.


1.2     Modeling Capabilities

SWMM accounts for various hydrologic processes that produce runoff from  urban areas. These
include:
    •   time-varying rainfall
    •   evaporation of standing surface water
    •   snow accumulation and melting
    •   rainfall interception from depression storage
    •   infiltration of rainfall into unsaturated soil layers
    •   percolation of infiltrated water into groundwater layers
    •   interflow between groundwater and the drainage system
    •   nonlinear reservoir routing of overland  flow
    •   capture and retention of rainfall/runoff with various types of low impact development (LID)
       practices.

Spatial variability in all of these processes is achieved by dividing a study area into a collection of
smaller, homogeneous subcatchment areas,  each  containing its own  fraction of pervious and
impervious sub-areas. Overland flow can be routed between sub-areas, between subcatchments,
or between entry points of  a drainage system.

SWMM also contains  a flexible set of hydraulic modeling capabilities used  to route  runoff and
external inflows through a drainage system network of  pipes, channels, storage/treatment units
and diversion structures. These include the ability to:
    •   handle networks of unlimited size
    •   use  a wide variety  of standard  closed and open conduit shapes  as well  as natural
       channels
    •   model special elements such as storage/treatment units, flow dividers, pumps, weirs, and
       orifices
    •   apply external flows  and water quality inputs from surface runoff, groundwater interflow,
       rainfall-dependent  infiltration/inflow, dry weather sanitary flow, and user-defined inflows
    •   utilize either kinematic wave or full dynamic wave flow routing  methods
    •   model various flow regimes, such as  backwater, surcharging, reverse flow, and surface
       ponding
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    •   apply user-defined  dynamic control  rules to simulate the operation of pumps,  orifice
       openings, and weir crest levels.

In addition to modeling the generation and transport of runoff flows, SWMM can also estimate the
production of pollutant loads associated with this runoff. The following  processes can be modeled
for any number of user-defined water quality constituents:
    •   dry-weather pollutant buildup over different land uses
    •   pollutant washoff from specific  land uses during storm events
    •   direct contribution of rainfall deposition
    •   reduction in dry-weather buildup due to street cleaning
    •   reduction in washoff load due to BMPs
    •   entry of dry weather sanitary flows and  user-specified external inflows at any point in the
       drainage system
    •   routing of water quality constituents through the drainage system
    •   reduction in constituent concentration through treatment  in storage units or by natural
       processes in pipes and channels.


1.3     Typical Applications of SWMM

Since its inception, SWMM has  been used in thousands of sewer and stormwater studies
throughout the world. Typical applications include:
    •   design and sizing of drainage system components for flood control
    •   sizing of detention facilities and their appurtenances for flood control and water quality
       protection
    •   flood plain mapping of natural channel systems
    •   designing control strategies for minimizing combined sewer overflows
    •   evaluating the impact of inflow  and infiltration  on sanitary sewer overflows
    •   generating non-point source pollutant loadings for waste load allocation studies
    •   evaluating the effectiveness of BMPs for reducing wet weather pollutant loadings.


1.4     Installing EPA SWMM

EPA SWMM Version 5 is designed to  run under all versions of the Microsoft Windows personal
computer operating system. It is distributed as a single file, swmm51xxx_setup.exe (where xxx is
the  current release number which as of this  writing is  010) that contains a self-extracting setup
program. To install EPA SWMM:
    l.  Select Run from the Windows Start menu.
    2.  Enter the full path and name of the setup file or click the Browse button to locate it on
       your computer.
    3.  Click the OK button type to begin the  setup process.

The setup program will ask you to  choose  a folder (directory) where the SWMM program files will
be placed. The default folder is c:\Program Files\EPA SWMM 5.1.  After the  files are  installed
your Start Menu  will have a new item  named EPA SWMM 5.1. To launch SWMM, simply select
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this item off of the Start Menu, and then select EPA SWMM 5.1 from the submenu that appears.
(The name of the executable file that runs SWMM under Windows is epaswmm5.exe.)

A user's personal settings for running SWMM are stored in a folder named EPASWMM under the
user's  Application  Data directory  (e.g., Users\\AppData\Roaming\EPASWMM for
Windows 7). If you need to save these settings to a different location,  you can install a shortcut to
SWMM 5 on the desktop whose target entry includes the name of the SWMM 5 executable
followed by /s , where   is the name of the folder where the personal
settings will be stored. An example might be:

    "c:\Program Files\EPA SWMM 5.1\epaswmm5.exe"/s "My Folders\SWMM5\".

Several example data  sets  have  been included  with the installation package to help  users
become familiar  with  the  program. They  are  placed in  a sub-folder named  EPA SWMM
Projects\Examples in the user's My Documents folder. Each example consists of a .INP file that
holds the project's data along with a .7X7file that describes the system being modeled.

To remove EPA SWMM from your computer, do the following:
    l.  Select Settings from the Windows Start menu.
    2.  Select Control Panel from the Settings menu.
    3.  Double-click on the Add/Remove Programs item.
    4.  Select EPA SWMM 5.1 from the list of programs that appears.
    5.  Click the Add/Remove button.


1.5     Steps in Using SWMM

One typically carries out the following steps when using EPA SWMM to model a study area:
    l.  Specify a default set of options and object properties to use (see Section 5.4).
    2.  Draw a network representation of the  physical components of the study area (see Section
       6.2).
    3.  Edit the properties of the objects that make  up the system (see Section 6.4).
    4.  Select a set of analysis options (see Section 8.1).
    5.  Run  a simulation (see Section 8.2).
    6.  View the results of the simulation (see Chapter 9).

For building larger systems from scratch it will be more convenient to  replace Step 2 by collecting
study area data from various sources, such as CAD drawings or CIS  files, and transferring these
data into a SWMM input file whose format is described in Appendix D  of this manual.
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1.6    About This Manual

Chapter 2 presents a short tutorial to help get started using EPA SWMM. It shows how to add
objects to a SWMM project, how to edit the properties of these objects, how to run a single event
simulation for both hydrology and  water quality,  and  how to  run  a long-term  continuous
simulation.

Chapter  3 provides background  material on how SWMM models stormwater runoff within  a
drainage area. It discusses the behavior of the physical components that comprise a stormwater
drainage area and collection system  as  well as how additional modeling information, such as
rainfall quantity, dry  weather sanitary inflows, and  operational control,  are handled.  It also
provides an overview of how the numerical simulation of system hydrology, hydraulics and water
quality behavior is carried out.

Chapter 4 shows how the EPA SWMM  graphical user interface is organized. It describes the
functions of the various menu options and toolbar buttons,  and how the three main windows - the
Study Area Map, the Browser panel, and the Property  Editor—are used.

Chapter 5 discusses the project files that store all of the information contained  in a SWMM model
of a drainage system. It shows how to create, open,  and  save these files as well as how to set
default project options. It also discusses how to register calibration data that are used to compare
simulation results against actual measurements.

Chapter 6 describes how one goes about building a network model of a drainage system with
SWMM. It shows how to create the various physical objects (subcatchment areas, drainage pipes
and channels,  pumps,  weirs,  storage units, etc.) that  make up a  system, how to edit  the
properties of these objects,  and  how to describe the way that externally imposed  inflows,
boundary conditions and operational controls change overtime.

Chapter 7 explains how to use the study  area map that provides a graphical view of the system
being  modeled. It shows how to view different design and computed parameters in color-coded
fashion on the map, how to re-scale, zoom, and pan the map, how to locate objects on the map,
how to utilize a  backdrop image, and what options are available to customize  the appearance of
the map.

Chapter 8 shows how to run a simulation of a SWMM  model. It describes the various options that
control how the analysis is made and offers some troubleshooting tips  to use when  examining
simulation results.

Chapter 9 discusses the various ways in  which the results of an analysis can be viewed. These
include different views of the study area  map, various kinds  of graphs and tables, and several
different types of special reports.

Chapter 10 explains how to print and copy the results discussed in Chapter 9.

Chapter  11  describes how EPA  SWMM can  use different types of  interface files to make
simulations runs more efficient.
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Chapter 12 describes how add-in tools can  be registered and share data with SWMM. These
tools are external applications launched from SWMM's graphical user interface that can extend its
capabilities.

The manual also contains several appendixes:
Appendix A-    provides several useful tables of parameter values, including a table of units of
               expression for all design and computed parameters.
Appendix B -    lists the editable properties of all visual objects that can be displayed on the
               study area map and be selected for editing using point and click.
Appendix C -    describes the specialized editors available for setting the properties of non-visual
               objects.
Appendix D -    provides  instructions  for running the command line  version of SWMM  and
               includes a detailed description of the format of a project file.
Appendix E -    lists all of the error messages and their meaning that SWMM can produce.
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                  CHAPTER 2 - QUICK START TUTORIAL
This chapter provides  a  tutorial on how to use EPA SWMM.  If you are not familiar with the
elements that comprise a drainage system, and how these are represented in a SWMM model,
you might want to review the material in Chapter 3 first.


2.1     Example Study Area

In this tutorial we will model the drainage system serving a 12-acre residential area. The system
layout is shown in Figure 2-1 and  consists of subcatchment areas3 S1 through S3, storm sewer
conduits C1 through C4, and conduit junctions J1 through J4. The system discharges to a creek
at the point labeled Out1. We will first go through the steps of creating the objects shown in this
diagram on SWMM's study area map and setting the various properties of these objects. Then we
will simulate the water quantity and quality response to a 3-inch, 6-hour rainfall event, as well as a
continuous, multi-year rainfall record.
                            Figure 2-1 Example study area
2.2    Project Setup

Our first task is to create a new SWMM project and make sure that certain default options are
selected. Using these defaults will simplify the data entry tasks later on.
    l.  Launch EPA SWMM  if it is not already running and select File » New from the Main
       Menu bar to create a new project.
    2.  Select Project » Defaults to open the Project Defaults dialog.
3 A subcatchment is an area of land containing a mix of pervious and impervious surfaces whose
runoff drains to a common outlet point, which could be either a node of the drainage network or
another subcatchment.
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3.  On the ID Labels page of the dialog, set the ID Prefixes as shown in Figure 2-2. This will
    make  SWMM automatically label new objects with consecutive numbers  following the
    designated prefix.
                    Project Defaults
ID Labels Subcatchments | Nodes/Links
Object
Rain Gages
Subcatchments
Junctions
Outfalls
Dividers
Storage Units
Conduits
Pumps
Regulators
ID Increment
ID Prefix
Gage I
S
J
Out


C


1

                       Save as defaults for all new projects
                 Figure 2-2 Default ID labeling for tutorial example
4.  On the Subcatchments page of the dialog set the following default values:
       Area
       Width
       % Slope
       % Imperv.
       N-lmperv.
       N-Perv.
       Dsto re-Imperv.
       Dstore-Perv
       %Zero-lmperv.
       Infil. Model
       - Method
       - Suction Head
       - Conductivity
       - Initial Deficit
4
400
0.5
50
0.01
0.10
0.05
0.05
25

Modified Green-Ampt
3.5
0.5
0.26
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    5.  On the Nodes/Links page set the following default values:
       Node Invert            0
       Node Max. Depth       4
       Node Ponded Area     0
       Conduit Length         400
       Conduit Geometry      
           - Barrels           1
           - Shape            Circular
           - Max. Depth       1.0
       Conduit Roughness     0.01
       Flow Units             CFS
       Link Offsets            DEPTH
       Routing Model         Kinematic Wave
    6.  Click  OK to accept  these  choices and  close the dialog. If you wanted to save these
       choices for all future  new projects you could check the Save box at the bottom of the form
       before accepting it.

Next we will set some map display options so that ID labels and symbols will be displayed as we
add objects to the study area map, and links will have direction arrows.
    l.  Select Tools » Map Display Options to bring up the Map Options dialog (see Figure 2-
       3).
    2.  Select the Subcatchments page, set the Fill Style to Diagonal and the Symbol Size to 5.
    3.  Then select the Nodes page and set the Node Size to 5.
    4.  Select the Annotation  page and check off the boxes  that will  display ID labels for
       Subcatchments, Nodes, and Links. Leave the others un-checked.
    5.  Finally, select the Flow Arrows page,  select the Filled arrow style, and set the arrow size
       to 7.
    6.  Click the OK button to accept these choices and close the dialog.
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                    Map Options
                     Subcatchments
                      Nodes

                      Links

                      Labels

                      Annotation

                      Symbols

                      Flow Arrows

                      Background
 Fill Style
 G Clear
  ;• solid
 (*) Diagonal
 O Cross Hatch
Symbol Size      5


Border Size       1


[7] Display link to outlet
                             OK
                              Figure 2-3 Map options dialog

Before placing objects on the map we should set its dimensions.
    l. Select View » Dimensions to bring up the Map Dimensions dialog.
    2. You can leave the dimensions at their default values for this example.

Finally, look in the status bar at the bottom of the main window and check that the Auto-Length
feature is off.


2.3    Drawing Objects

We are now ready to begin adding components to the Study Area Map4. We will start with the
subcatchments.
    l. Begin  by selecting the  Subcatchments category (under Hydrology)  in the  Project
       Browser panel (on the left side of the main window).
4 Drawing objects on the map is just one way of creating a project. For large projects it might be
more convenient to first construct a SWMM project file external to the program. The project file is
a text file that describes each object in a specified format as described in Appendix D of this
manual. Data extracted from various sources, such as CAD drawings or CIS files, can be used to
create the project file.
                                           21

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    2.  Then click the  *  button on the toolbar underneath the object category  listing  in the
       Project panel (or select Project  | Add a New Subcatchment from the  main menu).
       Notice how the mouse cursor changes shape to a pencil when you move  it over the map.
    3.  Move the mouse to the map location where one of the corners of subcatchment S1 lies
       and left-click the mouse.
    4.  Do the same for the next three corners and then right-click the  mouse (or  hit the  Enter
       key) to close up the rectangle that represents  subcatchment S1. You can press the Esc
       key if instead you wanted  to cancel your partially drawn subcatchment and start over
       again. Don't worry if the shape or position of the object isn't quite right. We will go back
       later and show how to fix this.
    5.  Repeat this process for subcatchments S2 and S35.
Observe how sequential ID  labels are generated automatically as we add objects  to the map.

Next we will add in the junction nodes and the outfall node that comprise  part of  the drainage
network.
    l.  To begin adding junctions, select the Junctions category from the Project  Browser
       (under Hydraulics -> Nodes) and  click the *  button or select Project |  Add a New
       Junction from the main menu..
    2.  Move the mouse to the  position of junction J1  and left-click it. Do the same for junctions
       J2 through J4.

    3.  To add the outfall node, select Outfalls from the Project Browser, click the  *  button or
       select Project | Add a New Outfall from the main menu, move the mouse to the outfall's
       location on the map, and left-click. Note how the outfall was automatically given the name
       Out1.
At this point your map should look something like that shown in Figure 2-4.
                                                       ,n
                                                       J2
              Figure 2-4 Subcatchments and nodes for example study area
5 If you right-click (or press Enter) after adding the first point of a subcatchment's outline, the
subcatchment will be shown as just a single point.
                                          22

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Now we will  add the storm sewer conduits  that connect our drainage system nodes to one
another.  (You must have created a link's end  nodes as described previously before  you can
create the link.) We will begin with conduit C1, which connects junction J1 to J2.
    l.  Select the Conduits from the Project Browser (under Hydraulics -> Links) and press the
        * button or select Project | Add a New Conduit from the  main  menu. The mouse
       cursor will change shape to a cross hair when  moved onto the map.
    2.  Left-click the mouse on junction J1.  Note how the mouse cursor changes shape to a
       pencil.
    3.  Move the mouse over to junction J2 (note how an outline of the conduit is drawn as you
       move the mouse) and left-click to create the  conduit.  You could have cancelled  the
       operation by either right clicking or by hitting the   key.
    4.  Repeat this procedure for conduits C2 through C4.

Although all of our conduits were drawn as straight lines, it is possible to draw a curved link by
left-clicking at intermediate points where the direction of the link changes  before clicking on the
end node.

To complete the construction of our study area schematic we need to add a rain gage.
    l.  Select the Rain Gages category from the Project Browser panel (under Hydrology) and
       either click the * button or select Project | Add a New Rain Gage from the main menu.
    2.  Move the mouse over the Study Area Map to where the gage should  be located  and left-
       click the mouse.

At this  point we have completed drawing the  example study area. Your system should  look like
the  one in Figure 2-1.  If a rain gage, subcatchment or node is out of position  you can move it by
doing the following:

    l.  If the  ^  button on the Map Toolbar is not already depressed, click it  to place the map in
       Object Selection  mode.
    2.  Click  on the object to be moved.
    3.  Drag the object with the left mouse button held down to its new position.

To re-shape a subcatchment's outline:
    l.  With the  map  in  Object Selection mode, click on the subcatchment's centroid (indicated
       by a solid square within the subcatchment) to select it.

    2.  Then  click the [^ button on the Map Toolbar to put the map into Vertex Selection mode.
    3.  Select a vertex point on the subcatchment outline by clicking on it (note how the selected
       vertex is  indicated by a filled solid square).
    4.  Drag the vertex to its new position with the left mouse button held down.
                                          23

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    5.   If need be, vertices can be added or deleted from the outline by right-clicking the mouse
        and selecting the appropriate option from the popup menu that appears.

    6.   When finished, click the ^ button to return to Object Selection mode.

This same procedure can also be used to re-shape a link.


2.4     Setting Object Properties

As visual objects are added to our project,  SWMM assigns them a default set of properties. To
change the value of a specific  property for an object we must select the object into the Property
Editor (see Figure 2-5). There are  several different ways to do this. If the Editor is already visible,
then you can simply click on the object or select it from the Project Browser. If the Editor is not
visible then you can make it appear by one of the following actions:
    •   double-click the object on the map,
    •   or right-click on the  object  and select Properties from the pop-up menu that appears,

    •   or select the object from the Project  Browser and then click the Browser's "^  button.
Subcatchment SI
Property
Name
(o)
Value
SI
X-Coordinate 4756,309
Y-Coordinate 6653,696
Description
Tag
Rain Gage
Outlet
Area
Width


Gagel
Jl
4
400
>.
D
T
Name of node or another
subcatchmentthat receives runoff
                            Figure 2-5 Property editor window

Whenever the Property Editor has the  focus you can press the F1 key to obtain a more detailed
description of the properties listed.

Two key properties of our subcatchments that need  to  be set are the rain gage that supplies
rainfall data to the  subcatchment and the node of the drainage system that receives runoff from
                                           24

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the subcatchment. Since all of our subcatchments utilize the same rain gage, Gagel, we can use
a shortcut method to set this property for all subcatchments at once:
    l.  From the main menu select Edit »Select All.
    2.  Then select Edit » Group Edit to make a Group Editor dialog appear (see Figure 2-6).
    3.  Select Subcatchment as the type of object to edit, Rain Gage as the property to edit, and
       type in Gagel as the new value.
    4.  Click OK to change the rain gage of all subcatchments to Gagel. A confirmation dialog
       will appear noting that 3 subcatchments have changed. Select "No" when  asked  to
       continue editing.
                    Group Editor
                      For objects of type
                        with Tag equal to
                      edit the property
                      by replacing it with
Subcatchment
Rain Gage
Gagel
                             Figure 2-6 Group editor dialog

To set the outlet node of our subcatchments we have to proceed one by one, since these vary by
subcatchment:
    l. Double click on subcatchment S1 or select it from the Project Browser and click the
       Browser's & button to bring up the Property Editor.
    2. Type J1 in the Outlet field and press Enter. Note  how a dotted line is drawn  between the
       subcatchment and the node.
    3. Click on subcatchment S2 and enter J2 as its Outlet.
    4. Click on subcatchment S3 and enter J3 as its Outlet.
We also wish to represent area S3 as being less developed than the others. Select S3 into the
Property Editor and set its % Imperviousness to 25.
                                          25

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The junctions and outfall of our drainage system need to have invert elevations assigned to them.
As we did with the subcatchments, select each junction individually into the Property Editor and
set its Invert Elevation to the value shown below6
Node
J1
J2
J3
J4
Out1
Invert
96
90
93
88
85
Only one of the conduits in our example system has a non-default property value. This is conduit
C4, the outlet pipe, whose diameter should be 1.5 instead of 1  ft. To change its diameter, select
conduit C4 into the Property Editor and set the Max. Depth value to 1.5.

In  order  to provide  a source  of rainfall input to our project  we need  to set the rain gage's
properties. Select Gagel into the Property Editor and set the following properties:

                             Rain Format   INTENSITY
                             Rain Interval    1:00
                             Data Source    TIMESERIES
                             Series Name    TS1

As mentioned  earlier, we want to simulate the response of our  study area to a 3-inch, 6-hour
design storm. A time series named TS1 will contain the hourly rainfall intensities that make up this
storm. Thus we need to create a time series object and populate it with data. To do this:
    l. From the Project Browser select the Time Series category of objects.

    2. Click the  *  button on  the Browser to bring up the Time Series Editor dialog (see Figure
       2-7)7.
    3. Enter TS1 in the Time Series Name field.
    4. Enter the values shown in Figure 2-7 into the Time and Value columns of the data entry
       grid (leave the Date column blank8).
    5. You can click the View button on the dialog to see a graph of  the time series values.
       Click the OK button to accept the new time series.
6 An alternative way to  move from one object of a given type to the next  in order (or to the
previous one) in the Property Editor is to hit the Page Down (or Page Up) key.
7 The Time Series Editor can also be launched directly from the Rain Gage Property Editor by
selecting the editor's Series Name field and double clicking on it.
8 Leaving off the dates for a time series means that SWMM will interpret the time values as hours
from the start of the simulation. Otherwise, the time series follows the date/time values specified
by the user.
                                           26

-------
                 Time Series Name
                 TS1

                 Description
                    Use external data file named below
                                                                     m
                 0 Enter time series data in the table below

                 No dates means times are relative to start of simulation,
Date
(M/D/YJ











Time
(H:M)
0
1
2
3
4
5
6




Value
0
05
1
0.75
05
0.25
0




6










T
                               Figure 2-7 Time series editor

Having completed the initial design of our example project it is a good idea to give it a title and
save our work to a file at this point. To do this:

    l.  Select the Title/Notes category from the Project Browser and click the & button.
    2.  In the Project Title/Notes dialog that appears (see Figure 2-8), enter "Tutorial Example"
       as the title of our project and click the OK button to close the dialog.
    3.  From the File menu select the Save As option.
    4.  In the Save As dialog that appears, select a folder and file name under which to save this
       project. We suggest naming the file tutorial.inp. (An extension of .inp will be added to
       the file name if one is not supplied.)
    5.  Click Save to save the project to file.
                                            27

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               Title/Notes Editor
             Tutorial Example
                Use title line as header for printing
                                                      OK
Cancel
                              Figure 2-8 Title/Notes editor

The project data are saved to the file in a readable text format. You can view what the file looks
like by selecting Project » Details from the main  menu. To open our project at some later time,
you would select the Open command from the File  menu.


2.5    Running a Simulation


Setting Simulation Options

Before analyzing the performance of our example drainage system we need to set some options
that determine how the analysis will be carried out.  To do this:

    l. From the Project Browser, select the Options category and click the  & button.
    2. On the  General page of the Simulation Options dialog  that  appears (see  Figure 2-9),
       select Kinematic Wave  as the flow routing  method. The  infiltration  method should
       already  be  set to  Modified Green-Ampt.  The  Allow Ponding option  should  be
       unchecked.
    3. On the Dates page of the dialog, set the End Analysis time to 12:00:00.
    4. On the Time Steps page, set the Routing Time Step to 60 seconds.
    5. Click OK to close the Simulation Options dialog.
                                          28

-------
Simulation

General
Options


Dates
Process Mode


















Time Steps
\r









Dynamic Wave | Files


[7] Rainfall/Runoff
D Rainfall Dependent L'l
D Snow Melt
^ Groundwater







[Vj Flow Routing
D Water Quality






Routing Mods


,1













O Steady Flow







•j*1 Kinematic Wave







Dynamic Wave











OK










Infiltration Model









Morton
Modifiec
Morton



Green-Ampt
o Modified
Green-Ampt
Curve Number




Miscellaneous















F] Allow Ponding
Q Report Control




Actions


! ; Report Input Summary






Minimum Conduit Slope
0



Cancel








(%}







Help

























                           Figure 2-9 Simulation options dialog
Starting a Simulation

We are now ready to run the simulation. To do so, select Project » Run Simulation (or click the
 @  button).  If there was a  problem with the simulation,  a Status Report will appear describing
what errors occurred. Upon successfully completing a run, there are numerous ways in which  to
view the results of the simulation. We will illustrate just a few here.


Viewing the Status Report

The Status Report contains useful information about the quality of a simulation run, including a
mass balance on rainfall, infiltration, evaporation,  runoff, and  inflow/outflow for the conveyance
system. To  view  the report select Report » Status (or click the H  button on the Standard
Toolbar and then  select Status Report from the drop down menu). A portion of the report for the
system just analyzed is shown in Figure 2-10.
                                           29

-------
            EPA STORM WATER MANAGEMENT MODEL  - VERSION  5.1  (Build  5.1.010)
              Tutorial  Example
              NOTE:  The  summary  statistics  displayed  in  this  report  are
              based  on results found  at  every  computational time  step,
              not  just on  results  from each reporting time step.
              Flow Units  	  CFS
              Process  Models:
                Rainfall/Runoff  	  YES
                RDII  	  NO
                Snowmelt  	  NO
                Groundwater  	  NO
                Flow Routing  	  YES
                Ponding Allowed  	  NO
                Water  Quality 	  NO
              Infiltration Method  	  MODIFIED_GREEN_AMPT
              Flow Routing Method  	  KINWAVE
              Starting Date  	  JUN-27-2002  00:00:00
              Ending Date  	  JUN-27-2002  12:00:00
              Antecedent Dry  Days  	  0.0
              Report Time  Step  	  00:15:00
              Wet  Time Step  	  00:15:00
              Dry  Time Step  	  01:00:00
              Routing  Time Step  	  60.00  sec
              Runoff  Quantity  Continuity
                                                               Depth
                                                              inches
              Total  Precipitation
              Evaporation  Loss  ...
              Infiltration Loss  ..
              Surface  Runoff  	
              Final  Storage 	
              Continuity Error  (%)
              Flow Routing  Continuity
                                               Volume
                                             acre-feet
             Wet Weather  Inflow
             Groundwater  Inflow
                          Figure 2-10 Portion of a Status Report

For the system we just analyzed the report indicates the quality of the simulation is quite good,
with  negligible mass balance  continuity errors  for both runoff and routing (-0.39% and  0.03%,
                                            30

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respectively, if all data were entered correctly). Also, of the 3 inches of rain that fell on the study
area, 1.75 infiltrated into the ground and essentially the remainder became runoff.


Viewing the Summary Report

The Summary Report contains tables listing summary results for each subcatchment, node and
link in the drainage system. Total rainfall, total runoff,  and  peak runoff for each subcatchment,
peak depth and  hours flooded for each node, and peak flow, velocity, and depth for each conduit
are just some of the outcomes included in the summary report.
To view the Summary Report select Report | Summary from the main menu  (or click the  U
button on the Standard Toolbar and then select Summary Report from the drop down menu).
The report's window has a drop down list from which you select a particular report to view. For
our example, the Node Flooding  Summary table  (Figure 2-11)  indicates there was internal
flooding in the system at node J2. Note. The Conduit Surcharge  Summary table (Figure 2-12)
shows that Conduit C2, just downstream of node J2, was at full capacity and therefore appears to
be slightly undersized.

In SWMM flooding will occur whenever the water surface at  a  node exceeds the maximum
assigned depth. Normally such water will be lost from the system. The option also exists to have
this water pond atop the node and be  re-introduced into the drainage system when  capacity
exists to do so.
iH Summary Results
Topic: Node Flooding T Click a column headerto sort the column.
Node
J2
Hours
Flooded
Maximum
Rate
CFS
1.05 ! 0.77
Day of
Maximum
Flooding
0
Hour of
Maximum
Flooding
03:01

| CD || H ||-£3-|

Total
Flood
Volume
10A6gal
0.018
Maximum
Ponded
Volume
1000 ft3
0.000

                       Figure 2-11 Node flooding summary table
   Topic:  Conduit Surcharge
T   Click a column headerto sort the column.


Conduit
C2

Hours
Both Ends
Full
1.03 i

Hours
Upstream
Full
1.03

Hours
Dn stream
Full
1.03
Hours
Above
Normal
Flow
1.05

Hours
Capacity
Limited
1.03
                     Figure 2-12 Conduit surcharge summary table
                                          31

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Viewing Results on the Map

Simulation results (as well as some design parameters, such as subcatchment area, node invert
elevation, and link maximum depth) can be viewed in color-coded fashion on the study area map.
To view a particular variable in this fashion:
    l.  Select the Map page of the Browser panel.
    2.  Select the variables to view for Subcatchments,  Nodes, and Links from the dropdown
       combo boxes appearing  in the Themes panel. In  Figure 2-13, subcatchment runoff and
       link flow have been selected for viewing.
  SJSWMM 5.1-tutorial.inp
  File  Edit View  Project  Report  Tools  Window  Help
D G£ y a
Project Map
Themes
Subcatchments

Runoff T
Nodes
None T
Links
Flow
Time Period
Date

06/27/2002
Time of Day
05:45:00
D
Elapsed Time
0.05:45:00
Animator
H < W >
1 0

3

                              E O
                                                                                    H
                           Study Area Map
                                                         J3
                                                       C3, ,
                                                                                         J1
                           Out1
                          T
C4
 <
 J4
*-
                               C2
  Auto-Length: Off  ^  Offsets: Depth  "•  Flow Units: CFS   "  *f   Zoom Level: 100%   X,Y: 5665.533,-2547.721
              Figure 2-13 Viewing color-coded results on the Study Area Map
                                           32

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    3. The color-coding  used for a particular variable is displayed with a legend on the study
       area map. To toggle the display of a legend, select View » Legends.
    4. To move a legend to another location, drag it with the left mouse button held down.
    5. To change the color-coding and the breakpoint values for different colors, select View »
       Legends » Modify and then the pertinent  class of object (or if the legend is already
       visible, simply right-click on it). To view numerical values for the variables being displayed
       on the map, select Tools » Map Display Options and then select the Annotation page
       of the Map Options dialog. Use the check boxes for Subcatchment Values, Node Values,
       and Link Values to specify what kind of annotation to add.
    6. The Date / Time  of Day / Elapsed Time controls on the  Map Browser can  be used to
       move through the simulation results in time. Figure 2-13 depicts results at 5 hours and 45
       minutes into the simulation.
    7. You can use the controls in the Animator panel of the Map Browser (see Figure 2-13) to
       animate the map  display through time. For example, pressing the  ^ button  will run the
       animation forward in time.
Viewing a Time Series Plot

To generate a time series plot of a simulation result:

    l .  Select Report » Graph » Time Series or simply click W;  on the Standard Toolbar.
    2.  A  Time Series Plot  Selection dialog will appear. It is used to  select the objects and
       variables to be plotted.

For our example, the Time Series Plot Selection dialog can be used to graph the flow in conduits
C1 and C2 as follows (refer to Figure 2-14a):
    l .  Click the Add button on the dialog to view the  Data Series Selection dialog (Figure 2-
    2 .  Select conduit C1 (either on the map or in the Project Browser) and select Flow as the
       variable to be plotted. Click the Accept button to return to the Time Series Plot Selection
       dialog.
    3 .  Repeat steps 1 and 2 for conduit C2.
    4 .  Press OK to create the plot which should look like the graph in Figure 2-1 5.
                                           33

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                     (a)
                                             (b)
Time Series Plot Selection
    'Q'1 Elapsed Time

    Data Series
Date/Time
        Add
        OK
                        Data Series Selection
                                                          Specify the object and variable to plot
                                                          (Click an object on the map to select it)
                                                      Object Type      Link
                           Object Name    Cl
                                                     Variable
                                                                      Flow
                                                      Legend Label


                                                      Axis            * Left    •'} Right
                                                           Help
   Figure 2-14 Time series plot dialogs
           : Graph - LinkCl Flow,.,
                                Link Cl flow (CFS) •
                            Link C2 flow (CFS}
            4.0

            3.5

            3.0

            2.5

            2.0

            1.5

            1.0

            0.5

            0.0
                                              6810
                                           Elapsed Time (hours)
                                                  12
14
                          Figure 2-15 Time series plot of link flows
                                               34

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After a plot is created you can:

    •    customize its appearance by selecting  Report »  Customize or by clicking the  Hf1
        button on the Standard Toolbar or by simply right clicking on the plot,
    •    copy it to the clipboard and paste it into another application by selecting Edit » Copy To
        or clicking ^ on the Standard Toolbar
    •    print it by selecting File » Print or File  » Print Preview (use File » Page Setup first
        to set margins, orientation, etc.).


Viewing a Profile Plot

SWMM can  generate  profile plots showing how water surface depth varies across a path of
connected nodes and links. Let's create such a plot for the conduits connecting junction J1 to the
outfall Out1  of our example drainage system. To do this:
l .  Select Report » Graph » Profile on the main menu or simply click
    Toolbar.
                                                                          j on the Standard
    2 .  Either enter J1  in the Start Node field of the Profile Plot Selection dialog that appears
        (see  Figure 2-16) or select it  on the map or from the Project Browser and click the  *
        button next to the field.
                    Profile Plot Selection

                      Create Profile

                      Start Node
                      Jl

                      End Node
                      OutL
                                           Links in Profile


                                            C2
                                            C4
                           Find Path
                        Save Current Profile
                                                             >  X
                              OK
                                      Cancel
                              Figure 2-16 Profile plot dialog
    3.  Do the same for node Out 1 in the End Node field of the dialog.
                                            35

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    4.  Click the Find Path button. An ordered list of the links forming a connected path between
       the specified Start and End nodes will be displayed in the Links in Profile box. You can
       edit the entries in this box if need be.
    5.  Click the OK button to create the plot, showing the water surface profile as it exists at the
       simulation time currently selected  in the Map Browser (see Figure 2-17 for hour 02:45).
          Profile-NodeJl-Out!
                     Water Elevation Profile:  NodeJI  - Out1
                             900   800   700  600  500   400   300  200   100    0
                                          Distance (ft)
                                                                06/27/2002 02:45:00
                            Figure 2-17 Example profile plot
As you move through time using the Map Browser or with the Animator control, the water depth
profile on the plot will be updated. Observe how node J2 becomes flooded between hours 2 and
3 of the storm event. A Profile Plot's appearance can  be customized and it can be copied  or
printed using the same procedures as for a Time Series Plot.


Running a Full Dynamic Wave Analysis

In the analysis just run we chose to  use the Kinematic Wave method of routing flows through our
drainage system. This  is an  efficient  but  simplified  approach that  cannot deal with such
phenomena  as  backwater effects,  pressurized flow, flow reversal,  and non-dendritic  layouts.
SWMM  also includes a Dynamic Wave  routing procedure that can represent these conditions.
This procedure,  however, requires more computation time, due to the  need for smaller time steps
to maintain numerical stability.
                                          36

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Most of the effects mentioned above would  not apply to our example. However we had one
conduit, C2, which flowed full and caused its upstream junction to flood. It could be that this pipe
is actually being  pressurized and could therefore convey more flow than was computed using
Kinematic Wave  routing. We would now like to see what would  happen if we apply Dynamic
Wave routing instead.
To run the analysis with Dynamic Wave routing:

    l .  From the Project Browser, select the Options category and click the
                                                                      button.
    2 .  On  the General  page of the Simulation Options dialog that appears, select  Dynamic
       Wave as the flow routing method.
    3.  On the Dynamic Wave page of the dialog, use the settings shown in Figure 2-1 89.
Simulation Options
1 General j Dates 1 Time Steps
Inertial Terms
Normal Flow Criterion
Force Main Equation
Dynamic Wave
TilesH

Dampen •*•
Slope
& Froude
-
Hazen-Williams T
[7] Use Variable Time Steps Adjusted By
Minimum Variable Time Step (sec)
Time Step
For Conduit Lengthening (sec)
Minimum Nodal Surface Area (sq. feet)
Maximum Trials per Time Step
Head Convergence Tolerance (feet)
Number of Threads
1 ™~> „. ' J '/ I....-" t* L



! OK 1


Cancel

75
0.5
0
". %


12.557
8
0.005
1

Help



T












                     Figure 2-18 Dynamic wave simulation options
9 Normally when running a Dynamic Wave analysis, one would also want to reduce the routing
time step (on the Time Steps page of the dialog). We will keep it at 60 seconds.
                                         37

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    4. Click OK to  close the form  and select Project » Run Simulation (or click the v
       button) to re-run the analysis.

If you look at the Summary Report for this run, you will see that there is no longer any junction
flooding and that the peak flow carried by conduit C2 has been increased from 3.52 cfs to 4.04
cfs.
2.6    Simulating Water Quality

In the next phase of this tutorial we will add water quality analysis to our example project. SWMM
has the ability to analyze the buildup, washoff, transport and treatment of any number of water
quality constituents. The steps needed to accomplish this are:
    l. Identify the pollutants to be analyzed.
    2. Define the categories of land uses that generate these pollutants.
    3. Set the parameters of buildup and washoff functions that determine the quality of runoff
       from each land use.
    4. Assign a mixture of land uses to each subcatchment area
    5. Define pollutant removal  functions  for nodes within the drainage  system that contain
       treatment facilities.
We will now apply each of these steps, with the exception of number 5, to our example project10.

We will define two runoff pollutants;  total suspended solids (TSS), measured as mg/L,  and  total
Lead, measured in ug/L. In addition, we will specify that the concentration of Lead in runoff is a
fixed fraction (0.25) of the TSS concentration. To add these pollutants to our project:
    l. Under the Quality category in the project Browser, select the Pollutants sub-category
       beneath it.

    2. Click the * button to add a new pollutant to the project.
    3. In the Pollutant  Editor dialog that appears (see Figure 2-19), enter  TSS for the pollutant
       name and leave the other data fields at their default settings.
    4. Click the OK button to close the Editor.

    5. Click the * button on the Project Browser again to add our next pollutant.
    6. In the  Pollutant Editor,  enter  Lead  for the pollutant name, select  UG/L  for  the
       concentration  units, enter TSS as the name of the Co-Pollutant, and enter 0.25 as the
       Co-Fraction value.
10 Aside from surface runoff, SWMM also allows pollutants to be introduced into the nodes of a
drainage system through  user-defined time  series  of direct  inflows,  dry  weather  inflows,
groundwater interflow, and rainfall dependent inflow/infiltration
                                           38

-------
    7.  Click the OK button to close the Editor.
In SWMM, pollutants associated with runoff are generated  by specific land uses  assigned to
subcatchments.  In our example, we will define two categories of land uses:  Residential and
Undeveloped. To add these land uses to the project:
    l.  Under the Quality category in the Project Browser, select the Land Uses sub-category
       and click the *  button.
    2.  In the  Land Use Editor dialog that appears  (see Figure 2-20), enter Residential in the
       Name  field and then click the OK button.
    3.  Repeat steps 1 and 2 to create the Undeveloped land use category.
 Pollutant Editor
  Property
 Name
 Units
 Rain Concen,
 GW Concen,
 I&I Concen,
 DWF Concen,
 Init, Concen,
 Decay Coeff,
 Snow Only
 Co-Pollutant
 Co-Fraction
Value
ITSS
MG/L
0,0
0,0
0,0
0,0
0,0
0,0
NO
 User-assigned name of the pollutant.
Land Use Editor
  General
Buildup I Washoffj
Property
Land Use Name
Description
STREET SWEEPING
Interval
Availability
Last Swept
Value
i Resident! a I


0
0
0
                                              User assigned name of land use,
    Figure 2-19 Pollutant editor dialog
                            Figure 2-20 Land use editor dialog
Next we need to define buildup and washoff functions for TSS in each of our land use categories.
Functions for Lead are not needed since its runoff concentration was defined to be a fixed fraction
of the TSS concentration. Normally, defining these functions requires site-specific calibration.
In this example we will assume that suspended solids in Residential areas builds up at a constant
rate of 1  pound per acre per day until a limit of 50 Ibs per acre is reached. For the  Undeveloped
                                           39

-------
area we will assume that buildup is only half as much. For the washoff function, we will assume a
constant event mean  concentration  of 100 mg/L  for  Residential  land and  50  mg/L  for
Undeveloped  land.  When runoff  occurs, these concentrations will  be maintained  until the
available buildup is exhausted. To define these functions for the Residential land use:

    l.  Select the Residential land use category from the Project Browser  and click the  &
       button.
    2.  In the Land Use Editor dialog, move to the Buildup page (see Figure 2-21).
    3.  Select TSS as the pollutant and ROW (for Power function) as the function type.
    4.  Assign the function a maximum buildup  of 50,  a rate  constant of 1.0,  a power of 1 and
       select AREA as the normalizer.
    5.  Move to the Washoff page of the dialog and select TSS as  the pollutant, EMC as the
       function type, and enter 100 for the coefficient. Fill the other fields with 0.
    6.  Click the OK button to accept your entries.

Now do the same for the Undeveloped  land use category, except use a maximum buildup of 25, a
buildup rate constant of 0.5, a buildup power of 1, and a washoff EMC of 50.
L
and Use Editor
General
Buildup
Pollutant

Property
Function
Max. Buildup
Rate Constant
Power/Sat. Consta
Normalizer
Buildup function:
exponential, SAT =
series.
OK ]



'wash off
g|
TSS
Value
JPOW
50
1.0
nt 1
ARE
3OW = pox
saturation
:A
TS^S^^^
ver, EXP =
, EXT = external time
Cancel


Help

i
                      Figure 2-21 Defining a TSS buildup function

The  final step  in our water quality example is  to assign  a  mixture  of land uses  to  each
subcatchment area:
                                          40

-------
    l.  Select subcatchment S1 into the Property Editor.
    2.  Select the Land Uses property and click the ellipsis button (or press Enter).
    3.  In the Land Use Assignment dialog that appears, enter 75 for the % Residential and 25
       for the % Undeveloped (see Figure 2-22). Then click the OK button to close the dialog.
                        Land Use Assignment
                        Land Use
% of Area
                        Residential

                        Undeveloped
25
                                        Cancel
                        Figure 2-22 Land use assignment dialog
    4.  Repeat the same three steps for subcatchment S2.
    5.  Repeat the same for subcatchment S3, except assign the land uses as 25% Residential
       and 75% Undeveloped.

Before we simulate the runoff quantities of TSS and Lead from our study area, an initial buildup of
TSS should be defined so it can  be washed off during our single rainfall event. We can either
specify the number of antecedent dry days prior to  the simulation or directly specify the  initial
buildup mass on each subcatchment. We will use the  former method:
    l.  From the Options category of the Project Browser, select the Dates sub-category and
       click the ^ button.
    2.  In the Simulation  Options  dialog that  appears, enter  5 into  the Antecedent Dry Days
       field.
    3.  Leave the other simulation options the same as they were  for the dynamic wave  flow
       routing we just completed.
    4.  Click the OK button to close the dialog.
Now run the  simulation by selecting Project » Run Simulation  or by clicking  ^?  on the
Standard Toolbar.

When the run is completed, view its Status Report. Note that two new sections have been added
for  Runoff Quality  Continuity and  Quality  Routing Continuity. From the Runoff  Quality
                                          41

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Continuity table we see that there was an initial buildup of 47.5 Ibs of TSS on the study area and
an additional 2.2  Ibs of buildup added during the dry periods of the simulation. About 47.9 Ibs
were washed off during the rainfall event. The quantity of Lead washed off is a fixed percentage
(25% times 0.001  to convert from mg to ug) of the TSS as was specified.

If you plot the runoff concentration of TSS for subcatchment S1 and S3 together on the same
time series graph, as in Figure 2-23, you will see the difference  in  concentrations resulting from
the different mix of land uses in these  two areas. You can also see that the duration over which
pollutants are washed off is much shorter than the duration of the entire runoff hydrograph (i.e., 1
hour versus about 6 hours). This results from  having exhausted the  available buildup of TSS over
this period of time.
           ! Graph - Subcatchment SI TSS...
                   E)
                     Subcatchment S1 TSS (MG.'L) -
Subcatchment S3 TSS (MG,1!)
            90.0

            80.0

            700

            600

          O 50.0
          s
          CO 40.0
          en
            300

            200

            100

             0,0
                                           6810
                                        Elapsed Time (hours)
                 12
14
                  Figure 2-23 Runoff TSS from selected subcatchments
2.7    Running a Continuous Simulation

As  a final  exercise  in this  tutorial we  will  demonstrate how to run a  long-term continuous
simulation using a  historical rainfall record and how to perform a statistical frequency analysis on
the results. The rainfall record will come from a file named sta310301.dat that was included with
the example data  sets provided with  EPA SWMM.  It contains several years of hourly rainfall
beginning in January 1998. The data are stored in the National Climatic Data Center's DSI 3240
format, which SWMM can automatically recognize.
                                           42

-------
To run a continuous simulation with this rainfall record:
    i.  Select the rain gage Gagel into the Property Editor.
    2.  Change the selection of Data Source to FILE.
    3.  Select the File Name data field and click the ellipsis button (or press the Enter key) to
        bring up a standard Windows File Selection dialog.
    4.  Navigate to the folder where the SWMM example files were stored, select the file named
        sta310301 .dat, and click Open to select the file and close the dialog.
    5.  In the Station No. field of the Property Editor enter 310301.
    6.  Select the Options category in the Project Browser and click the  ^ button to bring up
        the Simulation Options form.
    7.  On the General  page of the form, select Kinematic Wave as the Routing Method (this
        will help speed up the computations).
    8.  On the Dates page of the form, set both  the Start Analysis and  Start Reporting dates to
        01/01/1998, and  set the End Analysis date to 01/01/2000.
    9.  On the Time Steps page of the form, set the Routing Time Step to 300 seconds.
    10. Close the Simulation Options form by clicking the OK button and start the simulation by
        selecting Project » Run Simulation (or by clicking ^on  the Standard Toolbar).
After our continuous simulation is completed we can perform a statistical frequency analysis on
any  of the variables produced as output.  For example,  to determine the  distribution  of rainfall
volumes within each storm event over the two-year period simulated:
    l. Select Report » Statistics  or click the 2 button on the Standard  Toolbar.
    2. In the Statistics Selection dialog that appears, enter the values shown in Figure 2-24.
    3. Click the OK button to close the form.
                                           43

-------
                      Statistics Report Selection

                        Object Category        System
                        Variable Analyzed

                        Event Time Period

                        Statistic

                         Event Thresh olds

                           Precipitation

                           Event Volume

                           Separation Time
Precipitation

Event-Dependent

Total



       0

       0

       6
                              OK
                          Figure 2-24 Statistics selection dialog

The  results of this request will  be  a Statistics Report  form  (see Figure  2-25)  containing four
tabbed pages: a Summary page, an Events page containing a rank-ordered listing of each event,
a Histogram page containing  a plot  of the occurrence frequency versus event magnitude, and a
Frequency Plot page that plots event magnitude versus cumulative frequency.

The summary page shows that there were a total of 213 rainfall events. The Events page shows
that the largest rainfall event  had a  volume of 3.35 inches and occurred over a 24- hour period.
There were no events that matched the 3-inch, 6-hour design storm event used  in our previous
single-event analysis that had produced some internal flooding. In fact, the Summary Report for
this continuous simulation indicates that there were  no  flooding or surcharge occurrences over
the simulation period.
                                            44

-------
            Statistics - System  Precipitation
          Summary  Events f Histogram , Frequency Plot1
             SUMMARY
STATISTICS
            Object  ,,,	  System
            Variable .............  Precipitation   (in/hr)
            Event  Period .........  Variable
            Event  Statistic ......  Total (in)
            Event  Threshold 	  Precipitation > 0.0000   (in/hr)
            Event  Threshold 	  Event Volume > 0.0000  (in)
            Event  Threshold	  Separation Tinse >=  6.0   (hr)
            Period of  Record  	  01/01/1998 to 01/01/2000

            Number of  Events  	  213
            Event  Frequency*......  0. 076
            Minimum Value ........  0.010
            Maximum Value	  3, 350
            Mean Value	  0.309
            Std. Deviation	  0.449
            Skewness Coeff.  ......  3,161

            *Fraction  of all  reporting  periods belonging  to an event.
                          Figure 2-25 Example statistics report
We have only touched the surface of SWMM's capabilities. Some additional features of the
program that you will find useful include:
    •   utilizing additional  types  of drainage elements, such as  storage units, flow dividers,
       pumps, and regulators, to model more complex types of systems
    •   using control rules to simulate real-time operation of pumps  and regulators
    •   employing different types of externally-imposed  inflows at drainage system  nodes, such
       as direct time series inflows, dry weather inflows, and rainfall-derived infiltration/inflow
    •   modeling groundwater  interflow  between aquifers  beneath subcatchment areas and
       drainage system nodes
    •   modeling snow fall accumulation and melting within subcatchments
    •   adding calibration data to a project so that simulated  results can  be compared with
       measured values
    •   utilizing a background street, site plan,  or topo map to  assist in laying out a system's
       drainage elements and to help relate simulated results to real-world locations.
You can  find more information on  these and other features in  the remaining chapters of this
manual.
                                          45

-------
              CHAPTER 3 - SWMM'S CONCEPTUAL MODEL
This chapter discusses  how  SWMM models  the  objects and operational  parameters  that
constitute a stormwater drainage system. Details about how this information is entered into the
program are presented in later chapters. An overview is also given on the computational methods
that SWMM uses to simulate the hydrology, hydraulics and water quality behavior of a drainage
system.


3.1     Introduction

SWMM conceptualizes a drainage system as a series  of water and material flows between
several major environmental compartments. These compartments and the SWMM objects  they
contain include:
    •   The Atmosphere compartment, which generates precipitation and deposits pollutants
       onto the land surface compartment. SWMM uses  Rain Gage objects to  represent rainfall
       inputs to the system.
    •   The Land  Surface  compartment,   which  is  represented  through  one  or more
       Subcatchment objects.  It receives precipitation from the Atmospheric compartment in the
       form of rain or snow;  it sends outflow in  the form of  infiltration to the Groundwater
       compartment  and  also as  surface  runoff  and  pollutant loadings to  the  Transport
       compartment.
    •   The Groundwater compartment receives infiltration from the Land Surface compartment
       and transfers a portion  of this inflow to the Transport compartment. This compartment is
       modeled using Aquifer objects.
    •   The Transport compartment  contains a network of conveyance elements (channels,
       pipes, pumps, and regulators) and storage/treatment units that transport water to outfalls
       or to treatment facilities. Inflows to this compartment can come from surface runoff,
       groundwater interflow, sanitary dry weather flow, or from  user-defined hydrographs.  The
       components of the Transport compartment are modeled with Node and Link objects

Not all  compartments need  appear in a particular SWMM model.  For example,  one could model
just the transport compartment,  using pre-defined hydrographs as inputs.


3.2     Visual Objects

Figure  3-1 depicts how a collection of SWMM's visual objects might be arranged together to
represent a stormwater drainage system. These objects can be displayed on a map in the SWMM
workspace. The following sections describe each of these objects.
                                         46

-------
                    Raingage  *9
                               Divider
                          Storage Unit
                                                     Subcatchment
       Outfall
! Regulator
                                         Pump
              Figure 3-1  Physical objects used to model a drainage system
3.2.1   Rain Gages

Rain Gages supply precipitation data for one or more subcatchment areas in a study region. The
rainfall data can be  either a user-defined time series or come from an  external file. Several
different popular rainfall file formats currently in use are supported, as well as a standard user-
defined format. More details on these formats are presented in Section 11.3.

The principal input properties of rain gages include:
    •   rainfall data type (e.g., intensity, volume, or cumulative volume)
    •   recording time interval (e.g., hourly, 15-minute, etc.)
    •   source of rainfall data (input time series or external file)
    •   name of rainfall data source


3.2.2   Subcatchments

Subcatchments are hydrologic units of land whose topography and drainage system  elements
direct surface runoff to a single discharge point. The user is responsible for dividing a study area
into an  appropriate  number  of  Subcatchments,  and for identifying the  outlet  point  of each
subcatchment. Discharge  outlet  points can be either nodes of the  drainage system  or other
Subcatchments.

Subcatchments are divided into pervious and  impervious subareas. Surface  runoff can infiltrate
into the upper  soil zone  of the pervious subarea,  but not through  the  impervious  subarea.
Impervious areas are themselves  divided into two  subareas - one that contains depression
storage  and another  that  does not. Runoff flow from one subarea in  a subcatchment can  be
routed to the other subarea, or both subareas can drain to the subcatchment outlet.
                                           47

-------
Infiltration of rainfall from the pervious area of a subcatchment into the unsaturated  upper soil
zone can be described using four different models:
    •   Morton infiltration
    •   Modified Morton infiltration
    •   Green-Ampt infiltration
    •   Modified Green-Ampt infiltration
    •   Curve Number infiltration
To model the accumulation, re-distribution, and melting of precipitation that falls as snow  on a
subcatchment, it must be assigned a Snow Pack object. To model groundwater flow between an
aquifer underneath the subcatchment and a node of the drainage system, the subcatchment  must
be  assigned  a  set of Groundwater  parameters.   Pollutant  buildup  and  washoff  from
subcatchments  are associated with the  Land Uses assigned to the subcatchment. Capture and
retention  of rainfall/runoff using different types of low impact development practices (such as bio-
retention  cells, infiltration trenches, porous pavement, vegetative swales, and rain barrels) can be
modeled  by assigning a set of pre-designed LID controls to the subcatchment.
The other principal input parameters for subcatchments  include:
    •   assigned rain gage
    •   outlet node or subcatchment
    •   assigned land uses
    •   tributary surface area
    •   imperviousness
    •   slope
    •   characteristic width of overland flow
    •   Manning's n for overland flow on both pervious and impervious areas
    •   depression storage in both pervious and impervious areas
    •   percent of impervious area with no depression storage.

3.2.3   Junction Nodes
Junctions are drainage system nodes where links join together. Physically they can represent the
confluence of natural surface channels,  manholes in a sewer system, or pipe connection fittings.
External  inflows can enter  the system at junctions. Excess water at a junction can  become
partially pressurized while connecting conduits are surcharged and can either be lost from the
system or be allowed to pond atop the junction and subsequently drain back into the junction.
The principal input parameters for a junction are:
    •   invert (channel or manhole bottom) elevation
                                           48

-------
    •   height to ground surface
    •   ponded surface area when flooded (optional)
    •   external inflow data (optional).


3.2.4   Outfall Nodes

Outfalls are terminal nodes of the drainage system used to define final downstream boundaries
under Dynamic Wave flow routing. For other types of flow routing they behave as a junction. Only
a single link can be  connected to  an outfall node,  and the option exists to have  the  outfall
discharge onto a subcatchment's surface.

The boundary conditions at  an outfall  can  be  described  by any  one of the following  stage
relationships:
    •   the critical or normal flow depth in the  connecting conduit
    •   a fixed stage elevation
    •   a tidal stage described in a table of tide height versus hour of the day
    •   a user-defined time series of stage versus time.

The principal input parameters for outfalls include:
    •   invert elevation
    •   boundary condition type and stage description
    •   presence of a flap gate to prevent backflow through the outfall.


3.2.5   Flow Divider Nodes

Flow Dividers are drainage system nodes that divert inflows to a specific conduit in  a  prescribed
manner. A flow divider can have no more than two  conduit links on  its  discharge  side. Flow
dividers are only active under Steady Flow and Kinematic Wave routing and are treated as simple
junctions under Dynamic Wave routing.

There are four types of flow dividers, defined by the manner in which inflows are diverted:

    Cutoff Divider.      diverts all inflow above a defined cutoff value.
    Overflow Divider.    diverts  all  inflow  above  the  flow capacity of  the  non-diverted
                       conduit.
    Tabular Divider:    uses a table that expresses  diverted  flow as a function of total
                       inflow.
    Weir Divider.        uses a weir equation to compute diverted flow.

The flow diverted through a weir divider is computed by the following equation
                                            49

-------
where Qd,v = diverted flow, Cw = weir coefficient, Hw = weir height and /Ms computed as


     r 	 z~>in   i^min
          max   Xi-mm
where  Q/n is  the inflow to the divider,  Qm,n  is  the  flow at which  diversion  begins,  and
 O    — f ff^'^
 timax -   w  w _ jhe user-specified parameters for the weir divider are Qm/n, Hw, and Cw.
The principal input parameters for a flow divider are:
    •   junction parameters (see above)
    •   name of the link receiving the diverted flow
    •   method used for computing the amount of diverted flow.


3.2.6   Storage Units

Storage Units  are drainage  system  nodes that  provide storage volume. Physically they could
represent  storage  facilities as small as a  catch basin  or  as  large as  a  lake. The  volumetric
properties of a storage unit are described by a function or table of surface area versus height. In
addition to receiving inflows and discharging outflows to other nodes in the drainage network,
storage nodes can also lose water from surface evaporation  and from seepage into native soil.

The principal input parameters for storage units include:
    •   invert (bottom) elevation
    •   maximum depth
    •   depth-surface area data
    •   evaporation potential
    •   seepage parameters (optional)
    •   external inflow data (optional).


3.2.7   Conduits

Conduits are pipes or channels that move water from one node to another in the conveyance
system. Their cross-sectional shapes can be selected from a variety of standard open and closed
geometries as  listed in Table 3-1.

Most open channels can  be represented with a rectangular,  trapezoidal, or user-defined irregular
cross-section shape.  For the latter, a Transect object is used to define how depth varies  with
distance across the cross-section (see Section 3.3.5 below). Most new drainage and sewer pipes
are circular while culverts typically have elliptical or arch shapes.  Elliptical and Arch pipes come in
standard  sizes that are  listed in  Appendix A.12  and A.13. The  Filled Circular shape  allows the
bottom of a circular pipe to be filled  with sediment and thus limit  its flow capacity.  The Custom
                                            50

-------
Closed Shape allows any closed geometrical shape that is symmetrical about the center line to
be defined by supplying a Shape Curve for the cross section (see Sections.3.11 below).

SWMM  uses the Manning  equation to express the relationship between flow  rate (Q), cross-
sectional area (A), hydraulic radius (R), and slope (S) in all conduits. For standard U.S. units,
          n

where n is the Manning roughness coefficient. The slope S is interpreted as either the conduit
slope or the friction slope (i.e., head loss per unit length), depending on the flow routing method
used.

For pipes  with Circular Force Main cross-sections either the Hazen-Williams or Darcy-Weisbach
formula  is used in place of the Manning equation for fully pressurized flow. For U.S. units the
Hazen-Williams formula is:




where C is the Hazen-Williams C-factor which varies  inversely  with surface roughness and  is
supplied as one of the cross-section's parameters. The Darcy-Weisbach formula is:
where g is the acceleration of gravity and f is the Darcy-Weisbach friction factor. For turbulent
flow, the latter is determined from the height of the roughness elements on the walls of the pipe
(supplied as an  input parameter) and the flow's Reynolds Number using the Colebrook-White
equation. The choice of which equation to use is a user-supplied option.


        A  conduit does not have to be assigned a Force Main shape for it to  pressurize. Any of
        the closed cross-section shapes can potentially pressurize and thus function  as force
        mains that use the Manning equation to compute friction losses.

A  constant rate  of  exfiltration of water along  the length  of the  conduit can  be modeled  by
supplying  a Seepage Rate value (in/hr or mm/hr). This only accounts for seepage losses, not
infiltration  of rainfall  dependent groundwater. The latter can be modeled using SWMM's RDM
feature (see Section 3.3.6).
                                           51

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Table 3-1 Available cross section shapes for conduits
Name
Circular


Filled Circular

Rectangular
-Open


Triangular
Vertical
Ellipse

Parabolic

Rectangular-
Triangular
Modified
Baskethandle

Horseshoe
Catenary
Baskethandle
Irregular
Natural
Channel
Parameters
Full Height

Full Height,
Filled Depth

Full Height
Width

Full Height,
Top Width
Full Height,
Max. Width
Full Height,
Top Width
Full Height,
Top Width
Triangle
Height
Full Height,
Bottom
Width,
Top Radius
Full Height
Full Height
Full Height
Transect
Coordinates
Shape
$32

/"" X
&.>'j
^^^^^
m
/' ''
' V ,
/ f ' *



•\
r^
V
i ,
', * /
\J


• 7 ,.^4
«^£>
^"~r^\
$.?.•'!•

1 /' ,, i
^jJ
&&
~X
r ^
t^J
\ /
V F /
^
Name
Circular Force
Main

Rectangular -
Closed


Trapezoidal

Horizontal
Ellipse
Arch

Power

Rectangular-
Round

Egg

Gothic
Semi-Elliptical
Semi-Circular
Custom
Closed Shape
Parameters
Full Height,
Roughness

Full Height,
Width

Full Height,
Base Width,
Sirlp Slonp^

Full Height,
Max. Width
Full Height,
Max. Width
Full Height,
Top Width,
Exponent
Full Height,
Top Width
Bottom
Radius

Full Height

Full Height
Full Height
Full Height
Full Height,
Shape
Curve
Coordinates
Shape
®


'f *'',/<'

\ !'
'• T '


.-"' """-,.
> • ^
<:'»-;
^«,^,«*^
f'~~~---*
( '•'' ' Jr. '5
'"' * /
\''1
\/


?yr~3
•"•••^T ' jjju&^
O
^P

/""7\
i '' ' 'j
^J
h>\
I""" 5
**^iLLc,6t
\
fej .&£
P\
(^'•^
                        52

-------
A conduit can also be designated to act as a culvert (see Figure 3-2) if a Culvert Inlet Geometry
code number is assigned to it. These code numbers are listed in Appendix A.10.  Culvert conduits
are checked continuously  during dynamic wave flow routing to  see if they operate under Inlet
Control  as defined in  the Federal  Highway Administration's publication Hydraulic Design of
Highway Culverts  Third Edition  (Publication  No.  FHWA-HIF-12-026,  April  2012).  Under inlet
control a culvert obeys  a particular flow versus inlet depth rating curve whose shape depends on
the culvert's shape, size, slope, and inlet geometry.

               SB,.'.'
                             Figure 3-2 Concrete Box Culvert

The principal input parameters for conduits are:
    •   names of the inlet and outlet nodes
    •   offset height or elevation above the inlet and outlet node inverts
    •   conduit length
    •   Manning's roughness
    •   cross-sectional geometry
    •   entrance/exit losses (optional)
    •   seepage rate (optional)
    •   presence of a flap gate to prevent reverse flow (optional)
    •   inlet geometry code number if the conduit acts as a culvert (optional).
                                           53

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3.2.8   Pumps

Pumps are links used  to lift water to higher elevations. A pump curve describes the relation
between  a pump's flow rate and conditions at its inlet and outlet nodes. Five different types of
pump curves are supported:

Typel
An  off-line  pump with  a wet well
where flow increases incrementally
with available wet well volume                    •—n
                                                  Volume
Type2
An   in-line   pump  where  flow
increases incrementally with inlet
node depth.
                                                  Depth
Type3
An in-line pump where flow varies
continuously with head difference
between the inlet and outlet nodes.
                                                  Flow
Type4
A  variable  speed   in-line  pump
where flow varies continuously with
inlet node depth.
                                                  Depth
Ideal
An "ideal" transfer pump whose flow rate equals the inflow rate  at its inlet node.  No curve is
required. The pump must be the only outflow link from its inlet node. Used mainly for preliminary
design.

The on/off status of pumps can be controlled dynamically by specifying startup and shutoff water
depths at the inlet node or through user-defined Control  Rules. Rules can also  be used to
simulate variable speed drives that modulate pump flow.
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The principal input parameters for a pump include:
    •    names of its inlet and outlet nodes
    •    name of its pump curve (or * for an Ideal pump)
    •    initial on/off status
    •    startup and shutoff depths.


3.2.9    Flow Regulators

Flow Regulators are structures or devices used to control and divert flows within a conveyance
system. They are typically used to:
    •    control releases from storage facilities
    •    prevent unacceptable surcharging
    •    divert flow to treatment facilities and interceptors

SWMM can model the following types of flow regulators: Orifices, Weirs, and Outlets.

Orifices

Orifices are used to model outlet and diversion structures in drainage systems, which are typically
openings in the wall of a manhole, storage facility, or control gate. They are internally represented
in  SWMM  as  a  link connecting two nodes. An  orifice can have  either a circular or rectangular
shape, be  located either at the bottom or along the side of the upstream node, and have a flap
gate to prevent backflow.

Orifices can be used as storage unit outlets under all types  of flow routing.  If not attached to a
storage unit node, they can only be used in drainage networks that are analyzed with Dynamic
Wave flow  routing.

The flow through a fully submerged orifice is computed as
where  Q = flow rate, C = discharge coefficient, A = area of orifice opening, g = acceleration of
gravity, and h = head  difference across the orifice.  The height of an orifice's opening can be
controlled dynamically  through  user-defined Control  Rules. This feature can be used to model
gate openings and closings. Flow through a partially  full orifice is computed  using an equivalent
weir equation.

The principal input parameters for an orifice include:
    •   names of its inlet and outlet nodes
    •   configuration (bottom or side)
    •   shape (circular or rectangular)
    •   height or elevation above the inlet node invert
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       discharge coefficient
       time to open or close.
Weirs
Weirs, like orifices, are used to model outlet and diversion structures in a drainage system. Weirs
are typically located in a manhole, along the side of a channel, or within a storage unit. They are
internally represented in SWMM as a link connecting two nodes, where the weir itself is placed at
the upstream node. A flap gate can be included to prevent backflow.

Five varieties of weirs are  available, each  incorporating  a different  formula for computing flow
across the weir as listed in Table 3-2.
                            Table 3-2 Available types of weirs
Weir Type
Transverse
Side flow
V- notch
Trapezoidal
Roadway
Cross Section
Shape
Rectangular
Rectangular
Triangular
Trapezoidal
Rectangular
Flow Formula
CwLh^
CwLh^
CwSh^
CwLh^+CwsSh^
CwLh^
Cw = weir discharge coefficient, L = weir length, S = side slope of
V-notch or trapezoidal weir, h = head difference across the weir,
Cws = discharge coefficient through sides of trapezoidal weir.
The Roadway weir is a broad crested rectangular weir used model roadway crossings usually in
conjunction with culvert-type conduits (see Figure 3-2). It uses curves from the Federal Highway
Administration publication Hydraulic Design of Highway Culverts Third Edition (Publication  No.
FHWA-HIF-12-026, April 2012) to determine CM/as a function of h and roadway width.

Weirs can be used as storage unit outlets under all types of flow routing.  If not attached to a
storage unit, they can only be  used in drainage  networks that are analyzed with Dynamic Wave
flow routing.

The height of the weir crest above the inlet node invert can be controlled dynamically through
user-defined Control Rules. This feature can be used to model inflatable dams.

Weirs can either be allowed to surcharge or not. A surcharged weir will use an equivalent orifice
equation to compute the  flow through it. Weirs placed in open channels would normally not be
allowed to surcharge while those placed in closed diversion structures or those used to represent
storm drain inlet openings would be allowed to.
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The principal input parameters for a weir include:
    •    names of its inlet and outlet nodes
    •    shape and geometry
    •    crest height or elevation above the inlet node invert
    •    discharge coefficient.

Outlets

Outlets  are  flow control devices that are  typically used to control outflows from  storage units.
They  are  used to  model special  head-discharge  relationships that cannot be characterized by
pumps,  orifices,  or weirs. Outlets are internally represented  in SWMM as  a link connecting two
nodes. An outlet can also have a flap gate that restricts flow to only one direction.

Outlets  attached to storage  units are active under all types  of flow routing. If not attached  to a
storage  unit, they can only be used in drainage networks  analyzed  with Dynamic Wave  flow
routing.

A  user-defined rating curve determines an outlet's discharge flow  as a function of either the
freeboard  depth above the outlet's opening or the head difference across it. Control Rules can be
used to  dynamically adjust this flow when certain conditions exist.

The principal input parameters for an outlet include:
    •    names of its inlet and outlet nodes
    •    height or elevation above the inlet node invert
    •    function or table containing its head (or depth) - discharge relationship.

3.2.10  Map Labels

Map Labels  are optional text labels added to SWMM's Study Area Map to help identify particular
objects  or regions of the map. The labels can be drawn in any Windows font, freely edited and be
dragged to any position on the map.
3.3     Non-Visual Objects

In addition to physical  objects that can be displayed visually on a map, SWMM utilizes several
classes of non-visual data  objects to describe additional characteristics and processes within a
study area.
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3.3.1 Climatology

Temperature

Air temperature data are  used when simulating snowfall and snowmelt processes during runoff
calculations. They can also be used to compute daily evaporation rates. If these processes are
not being simulated then temperature data are not required. Air temperature data can be supplied
to SWMM from one of the following sources:
    •   a user-defined time series of point values (values at intermediate times are interpolated)
    •   an  external  climate file containing daily minimum and maximum values (SWMM fits a
       sinusoidal curve through these values depending on the day of the year).
For user-defined time series, temperatures  are in degrees F  for US units and  degrees C for
metric units. The external climate file can also be used to directly supply evaporation and wind
speed as well.

Evaporation

Evaporation can occur for standing water on  subcatchment surfaces, for subsurface water in
groundwater aquifers, for water traveling through open channels, and for water held in storage
units.  Evaporation rates can be stated as:
    •   a single constant value
    •   a set of monthly average values
    •   a user-defined time series of values
    •   values computed from the daily temperatures contained in an external climate file
    •   daily values  read directly from an external climate file.
If rates are read directly from a climate file, then a set of monthly pan coefficients should also be
supplied to convert  the pan evaporation data to free water-surface values. An option is also
available to allow evaporation only during periods with no precipitation.

Note  that the evaporation rates supplied to SWMM  are potential rates. The  actual amount of
water evaporated will depend on the amount of water available.

Wind  Speed

Wind  speed is an optional climatic variable that is only used for snowmelt calculations.  SWMM
can use either a  set of monthly average speeds or  wind speed data contained in the  same
climate file used for daily minimum/maximum temperatures.

Snowmelt

Snowmelt parameters  are  climatic  variables  that apply  across  the  entire study area  when
simulating snowfall and snowmelt. They include:
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    •   the air temperature at which precipitation falls as snow
    •   heat exchange properties of the snow surface
    •   study area elevation, latitude, and longitude correction

Areal Depletion

Areal  depletion refers to the tendency of accumulated snow to melt non-uniformly over the
surface of a subcatchment. As  the melting  process proceeds, the area covered  by snow gets
reduced.  This  behavior is described by an Areal Depletion Curve that plots the fraction of total
area that remains snow covered against the ratio of the actual snow depth to the depth at which
there is 100% snow cover.  A typical ADC for a natural area is shown in Figure 3-3. Two such
curves can be supplied to SWMM, one for impervious areas and another for pervious areas.
                   o
                   "•S
                   is
                     0.8
                     0.6
                     04
                     0.2
                         0       0.2      0.4      0.6      0,8       1
                                  Fraction Snow Covered Area

                    Figure 3-3  Areal depletion curve fora natural area

Climate Adjustments

Climate Adjustments are optional modifications applied to the temperature, evaporation rate, and
rainfall intensity that SWMM would otherwise use at each time step of a simulation. Separate sets
of adjustments that vary periodically by month  of the year can be assigned to these variables.
They  provide a simple way to examine the  effects of future climate change without having to
modify the original climatic time series.

In a similar manner, a set of monthly  adjustments can be applied to the  hydraulic conductivity
used  in computing  rainfall  infiltration  on  pervious land surfaces and  exfiltration from storage
nodes and conduits. These can reflect  the  increase  of hydraulic conductivity with  increasing
temperature or the effect that seasonal  changes in land surface conditions, such as frozen
ground, can have on infiltration capacity.
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3.3.2   Snow Packs

Snow Pack objects contain parameters that characterize the buildup, removal,  and melting of
snow over three types of sub-areas within a subcatchment:
    •   The Plowable snow pack area consists of a user-defined fraction of the total impervious
       area.  It is meant to represent such areas as streets and parking lots where plowing and
       snow  removal can be done.
    •   The   Impervious  snow  pack  area  covers  the  remaining  impervious  area   of  a
       subcatchment.
    •   The Pervious snow pack area encompasses the entire pervious area of a subcatchment.

Each of these three areas is characterized by the following parameters:
    •   Minimum and maximum snow melt coefficients
    •   minimum air temperature for snow melt to occur
    •   snow  depth above which 100% areal coverage occurs
    •   initial  snow depth
    •   initial  and maximum free water content in the pack.

In  addition, a set  of snow removal parameters can  be assigned to the Plowable area. These
parameters consist of the depth at which snow removal begins and the fractions of snow moved
onto various other areas.

Subcatchments  are assigned a snow pack object through their Snow Pack property. A single
snow pack object can be applied to any number of subcatchments. Assigning a snow pack to a
subcatchment simply establishes  the  melt  parameters and  initial  snow conditions  for that
subcatchment. Internally, SWMM creates a "physical" snow pack for each subcatchment, which
tracks snow accumulation and melting for that particular subcatchment based on its snow  pack
parameters, its amount of pervious and impervious area, and the  precipitation history it sees.


3.3.3   Aquifers

Aquifers are  sub-surface  groundwater zones  used to model the  vertical movement of water
infiltrating  from  the subcatchments that lie  above them.  They also permit the infiltration of
groundwater into the drainage system, or exfiltration of surface water from the drainage system,
depending on the hydraulic gradient that exists. Aquifers are only required in models that need to
explicitly account for the exchange of groundwater with the drainage system or to establish  base
flow and recession curves in natural channels and non-urban systems. The parameters of an
aquifer object can  be shared by several subcatchments but there is no exchange  of groundwater
between subcatchments. A drainage system  node can  exchange groundwater with  more  than
one subcatchment.

Aquifers are represented using  two zones - an un-saturated zone and a saturated  zone. Their
behavior  is  characterized  using  such parameters  as  soil porosity,  hydraulic  conductivity,
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evapotranspiration depth, bottom elevation, and loss rate to deep groundwater. In addition, the
initial water table elevation and initial moisture content of the unsaturated zone must be supplied.

Aquifers  are  connected  to  subcatchments  and  to  drainage  system  nodes  through  a
subcatchment's Groundwater Flow property. This property also contains parameters that govern
the rate of groundwater flow between the aquifer's saturated zone and the drainage system node.


3.3.4   Unit Hydrographs

Unit Hydrographs (UHs) estimate rainfall-dependent infiltration/inflow (RDM) into a sewer system.
A  UH set contains up to three  such  hydrographs,  one for a short-term response, one for an
intermediate-term response, and one for a  long-term response. A UH group can have up to 12
UH sets,  one for each month of  the year. Each UH group is considered as a separate object by
SWMM, and is assigned  its own  unique name along with the name of the rain gage that supplies
rainfall data to it.

Each unit hydrograph, as shown  in Figure 3-4, is defined by three parameters:
   •   R: the fraction of rainfall volume that enters the sewer system
   •   T: the time from the onset of rainfall  to the peak of the UH in hours
   •   K: the ratio of time to recession of the UH to the time to peak
                    Qpeak
             3
             o
                                        Time
                           Figure 3-4 An RDM unit hydrograph

Each unit hydrograph can also have a set of Initial Abstraction (IA) parameters associated with it.
These  determine  how much rainfall  is lost to interception and depression storage before  any
excess rainfall is generated and transformed into RDM flow by the hydrograph. The IA parameters
consist of:
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    •   a maximum possible depth of IA (inches or mm),
    •   a recovery rate (inches/day or mm/day) at which stored IA is depleted during dry periods,
    •   an initial depth of stored IA (inches or mm).
To  generate  RDM into a drainage  system node, the  node must identify (through its Inflows
property) the UH group and  the area  of the surrounding sewershed that contributes RDM flow.
       An alternative to using unit hydrographs to define RDM flow is to create an external RDM
       interface file, which contains RDM time series data. See Section 11.7 Interface Files.
 W    Unit hydrographs could also be used to replace SWMM's main rainfall-runoff process that
       uses Subcatchment objects,  provided that properly calibrated UHs are utilized.  In this
       case what SWMM calls RDM inflow to a node would actually represent overland runoff.


3.3.5   Transects

Transects refer to the geometric data that describe  how bottom elevation varies with horizontal
distance  over the  cross  section of a natural channel  or  irregular-shaped  conduit.  Figure 3-5
displays an example transect for a natural channel.
                                        Transect 92

                                     Qverbark •» Channe-
       304

       303

       802

       801

       800

       799

       798
           0   10   20   30   40   50   60   70   80   90   100  110   120  130  140   150  160
                                             Station (ft)
                    Figure 3-5 Example of a natural channel transect

Each  transect must be given  a unique name. Conduits  refer to that name to represent their
shape. A special Transect Editor is available for editing the station-elevation data of a transect.
SWMM internally converts these data into tables of area, top width, and hydraulic radius versus
channel depth. In  addition, as shown  in Figure  3-5,  each transect can  have a left and right
overbank section whose Manning's  roughness can be different from that of the main channel.
This feature  can  provide more realistic estimates of channel  conveyance  under  high flow
conditions.
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3.3.6   External Inflows

In  addition to inflows originating from subcatchment runoff and groundwater, drainage system
nodes can receive three other types of external inflows:
    •   Direct Inflows - These are user-defined time series of inflows added directly into a node.
       They can be used to perform flow and water quality routing in the absence of any runoff
       computations (as in a study area where no subcatchments are defined).
    •   Dry Weather Inflows - These are continuous inflows that typically reflect the contribution
       from sanitary sewage  in sewer systems or base flows in  pipes  and stream  channels.
       They are represented  by an  average inflow rate that  can be periodically adjusted on a
       monthly,  daily, and  hourly basis  by applying Time Pattern multipliers to this average
       value.
    •   Rainfall-Dependent Infiltration/Inflow (RDM) - These  are stormwater flows that enter
       sanitary or combined  sewers due to "inflow" from direct  connections of downspouts,
       sump pumps, foundation drains, etc. as well as "infiltration" of subsurface water through
       cracked pipes, leaky joints, poor manhole connections, etc. RDM can be computed for a
       given rainfall  record based on set of triangular unit hydrographs  (UH) that determine a
       short-term, intermediate-term, and  long-term inflow response for each time  period of
       rainfall. Any number of UH  sets can be supplied for different sewershed areas  and
       different months of the year. RDM flows can also be specified in an external RDM interface
       file.

Direct,  Dry Weather, and RDM inflows are  properties associated  with  each type of  drainage
system node (junctions,  outfalls, flow dividers, and storage units) and can be specified when
nodes are edited. They can  be used  to perform flow and water quality routing in the absence of
any runoff computations (as in a study area where no subcatchments  are defined).  It is  also
possible to make the  outflows  generated from an upstream drainage system be the inflows  to a
downstream system by using interface files. See Section 11.7 for further details.


3.3.7   Control Rules

Control Rules determine how pumps  and regulators in the drainage system will be adjusted  over
the course of a simulation. Some examples of these rules are:

Simple time-based pump control:
RULE R1
IF  SIMULATION TIME > 8
THEN PUMP 12 STATUS = ON
ELSE PUMP 12 STATUS = OFF

Multiple-condition orifice gate control:
RULE R2A
IF  NODE 23 DEPTH > 12
AND LINK 165 FLOW > 100
THEN ORIFICE R55 SETTING = 0.5
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RULE R2B
IF NODE 23 DEPTH > 12
AND LINK 165 FLOW > 200
THEN ORIFICE R55 SETTING = 1.0

RULE R2C
IF NODE 23 DEPTH <= 12
OR LINK 165 FLOW <= 100
THEN ORIFICE R55 SETTING = 0

Pump station operation:
RULE R3A
IF NODE N1 DEPTH > 5
THEN PUMP N1A STATUS = ON

RULE R3B
IF NODE N1 DEPTH > 7
THEN PUMP N1B STATUS = ON

RULE R3C
IF NODE N1 DEPTH <= 3
THEN PUMP N1A STATUS = OFF
AND PUMP N1B STATUS = OFF

Modulated weir height control:
RULE R4
IF NODE N2 DEPTH >= 0
THEN WEIR W25 SETTING = CURVE C25

Appendix C.3 describes the control rule format in more detail and the special Editor used to edit
them.
3.3.8   Pollutants

SWMM can  simulate  the  generation, inflow and transport of any number  of user-defined
pollutants. Required information for each pollutant includes:
    •   pollutant name
    •   concentration units (i.e., milligrams/liter, micrograms/liter, or counts/liter)
    •   concentration in rainfall
    •   concentration in groundwater
    •   concentration in inflow/infiltration
    •   concentration in dry weather flow
    •   initial concentration throughout the conveyance system
    •   first-order decay coefficient.
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Co-pollutants can also be defined in SWMM. For example, pollutant X can have a co-pollutant Y,
meaning that the runoff concentration  of  X  will  have  some  fixed  fraction  of the runoff
concentration of Y added to it.

Pollutant buildup and washoff from subcatchment  areas are determined  by the land uses
assigned to those areas.  Input loadings of pollutants to the drainage system can also originate
from external time series inflows as well as from dry weather inflows.


3.3.9    Land  Uses

Land Uses are categories of development activities or land surface characteristics assigned to
subcatchments.  Examples of  land  use  activities are residential, commercial, industrial,  and
undeveloped.  Land  surface  characteristics  might  include  rooftops,  lawns,  paved  roads,
undisturbed soils, etc. Land  uses are used  solely to account for spatial  variation in pollutant
buildup and washoff rates within subcatchments.

The SWMM user has many options for defining land uses and assigning them  to subcatchment
areas. One approach is to assign a mix of land uses for each subcatchment, which results in all
land  uses within  the subcatchment  having the same pervious and impervious characteristics.
Another approach is to create subcatchments that have a single land use classification along with
a distinct set of pervious and  impervious characteristics that reflects the classification.

The following processes can  be defined for each land  use category:
   •    pollutant buildup
   •    pollutant washoff
   •    street cleaning.

Pollutant Buildup

Pollutant buildup that accumulates within a land use category is described (or "normalized")  by
either a mass per unit of subcatchment area or per unit  of curb length.  Mass is expressed in
pounds  for US units and  kilograms for metric units. The amount  of buildup is  a function of the
number of preceding dry weather days and can be computed using one of the following  functions:

Power Function: Pollutant  buildup  (B) accumulates proportionally to time  (t)  raised to some
power, until a maximum limit  is  achieved,
    B=Min(ci,C2tC3)
where C? = maximum buildup possible (mass per unit of area or curb length), €2 = buildup rate
constant, and Cs = time exponent.

Exponential Function: Buildup follows an exponential growth curve that approaches a maximum
limit asymptotically,
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where C? = maximum buildup possible (mass per unit of area or curb length) and €2 = buildup
rate constant (1/days).

Saturation Function: Buildup begins at a linear rate that continuously declines with time until a
saturation value is reached,
        C2+t

where  C?  = maximum buildup  possible (mass  per unit area or curb length) and  62 = half-
saturation  constant (days to reach half of the maximum buildup).

External Time Series: This option  allows one  to  use  a Time Series to describe the rate of
buildup per day as a function of time. The values placed in the time series would have units of
mass per  unit area (or curb length) per day. One can also provide a maximum possible buildup
(mass  per unit area or curb length) with this option  and  a scaling factor that multiplies the time
series values.

Pollutant Washoff

Pollutant washoff from a given land use category occurs  during wet weather periods and can be
described  in one of the following ways:

Exponential Washoff: The washoff load (I/I/) in units of mass per hour is proportional  to the
product of runoff raised to some power and to the amount of buildup remaining,

    W = C,qClB

where  C? = washoff coefficient, €2 = washoff exponent, q = runoff rate per unit area (inches/hour
or mm/hour), and 8 =  pollutant buildup in mass units. The buildup here is the total mass (not per
area or curb length) and both buildup and washoff mass units are the same as used to express
the pollutant's concentration (milligrams, micrograms, or counts).

Rating Curve Washoff: The rate of washoff I/I/ in mass  per second is proportional to the runoff
rate raised to some power,

    W = C,QC2

where  C?  = washoff coefficient, €2 = washoff exponent, and Q = runoff rate in user-defined flow
units.
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Event Mean Concentration: This is a special case of Rating Curve Washoff where the exponent
is  1.0 and  the coefficient  Ci represents the washoff pollutant concentration  in mass per liter
(Note: the  conversion between user-defined flow units used for runoff  and  liters is handled
internally by SWMM).

Note that in  each case buildup is continuously depleted as washoff proceeds,  and washoff
ceases when  there is no more buildup available.

Washoff loads for a given pollutant and land use category can be  reduced  by a fixed percentage
by specifying a BMP Removal Efficiency that  reflects the effectiveness  of any BMP controls
associated  with the land  use. It is also possible to use the Event  Mean Concentration option by
itself, without  having to model any pollutant buildup at all.

Street Sweeping

Street sweeping can  be used on each land use category to periodically reduce the accumulated
buildup of specific pollutants. The parameters that describe street sweeping include:
    •   days  between sweeping
    •   days since the last sweeping at the start of the simulation
    •   the fraction of buildup of all pollutants that is available for removal by sweeping
    •   the fraction of available buildup for each pollutant removed by sweeping
Note that these  parameters can be different for each land use, and the last parameter can vary
also with  pollutant.


3.3.10  Treatment

Removal  of pollutants from the flow streams entering any drainage system node is modeled by
assigning a set of treatment functions to the node. A treatment function can be any well-formed
mathematical expression involving:
    •   the pollutant concentration
    •   the removals of other pollutants
    •   any of several process variables, such as flow rate, depth,  hydraulic residence time, etc.

The result of  the treatment function can be either a concentration (denoted by the letter C) or a
fractional removal (denoted by R). For example, a first-order  decay  expression for BOD exiting
from a storage node might  be expressed as:
    C = BOD  *exp(-0.05 *HRT)

where HRT is the reserved variable name for  hydraulic residence time. The  removal of some
trace pollutant that is proportional to the  removal of  total suspended solids  (TSS) could  be
expressed as:
    R = 0.75*R  TSS
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Section C.22 provides more details on how user-defined treatment equations are supplied to the
program.

3.3.11   Curves
Curve objects are used to describe a functional relationship between two quantities. The following
types of curves are used in SWMM:
    •   Storage - describes how the surface area of a Storage Unit node varies with water depth.
    •   Shape - describes how the width of a  customized cross-sectional shape varies with
        height for a Conduit link.
    •   Diversion - relates diverted outflow to total inflow for a Flow Divider node.
    •   Tidal - describes how the stage at an Outfall node changes by hour of the day.
    •   Pump - relates flow through a Pump link to the depth or volume at the upstream node or
        to the head delivered by the pump.
    •   Rating - relates flow through an  Outlet link to the freeboard depth or head difference
        across the outlet.
    •   Control  - determines how the control setting  of a pump or flow regulator varies as a
        function of some control variable (such as water level at a particular node) as specified in
        a Modulated Control rule.
Each curve must be given a unique name and can be assigned any number of data pairs.
3.3.12  Time Series
Time Series objects are  used to describe how certain object  properties vary with time. Time
series can be used to describe:
    •   temperature data
    •   evaporation data
    •   rainfall data
    •   water stage at outfall nodes
    •   external inflow hydrographs at drainage system nodes
    •   external inflow pollutographs at drainage system nodes
    •   control settings for pumps and flow regulators..
Each time series must  be given a unique name and can be assigned any number of time-value
data pairs. Time can be specified either as hours from the start of a simulation or as an absolute
date and time-of-day. Time series data can  either be entered directly into the program or be
accessed from a user-supplied Time Series file.
       For  rainfall  time  series, it is  only  necessary to enter periods  with  non-zero  rainfall
       amounts.  SWMM interprets the  rainfall  value  as a  constant value  lasting  over the
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        recording interval specified for the  rain gage that utilizes the time series. For all other
        types of time series, SWMM  uses  interpolation to estimate values at times that fall in
        between the recorded values.
        For times that fall outside the range of the time series, SWMM will use a value of 0 for
        rainfall  and external  inflow time series,  and  either  the  first or last  series value for
        temperature, evaporation, and water stage time  series.
3.3.13  Time Patterns

Time Patterns allow external Dry Weather Flow (DWF) to vary in a periodic fashion. They consist
of a set  of adjustment factors applied as multipliers to a baseline  DWF flow rate or pollutant
concentration. The different types of time patterns include:
    Monthly   - one multiplier for each month of the year
    Daily      - one multiplier for each day of the week
    Hourly     - one multiplier for each hour from 12 AM to 11 PM
    Weekend   - hourly multipliers for weekend days
Each Time Pattern must have a unique name and there is no limit on the number of patterns that
can be created. Each  dry weather inflow (either flow or quality)  can have up to four  patterns
associated with it, one for each type listed above.
3.3.14   LID Controls

LID Controls are low  impact  development  practices designed to capture surface runoff  and
provide some  combination  of detention, infiltration, and  evapotranspiration  to it.  They  are
considered as properties of a given subcatchment, similar to how Aquifers and Snow  Packs are
treated. SWMM can explicitly model eight different generic types of LID controls:
                       Bio-retention Cells are depressions that contain vegetation grown in an
                       engineered soil  mixture  placed  above  a gravel  drainage  bed. They
                       provide storage,  infiltration  and evaporation  of both direct rainfall  and
                       runoff captured from surrounding areas.


                       Rain  Gardens are a type of bio-retention  cell consisting  of just the
                       engineered soil layer with no gravel bed below it.
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                       Green Roofs are another variation of a bio-retention cell that have a soil
                       layer laying atop a special drainage mat material that conveys excess
                       percolated rainfall off of the roof.
                       Infiltration Trenches are narrow ditches filled with gravel that intercept
                       runoff from upslope impervious areas. They provide storage volume and
                       additional time for captured runoff to infiltrate the native soil below.
                       Continuous Permeable Pavement systems are excavated areas filled
                       with gravel and  paved over with  a  porous concrete or asphalt  mix.
                       Normally all rainfall will immediately pass through the pavement into the
                       gravel storage layer below it where it can infiltrate at natural rates  into
                       the site's native soil. Block Paver systems consist of impervious paver
                       blocks placed on a sand or pea gravel  bed  with a gravel storage layer
                       below. Rainfall is captured in the open spaces between the blocks  and
                       conveyed to the storage zone and native soil below.
                       Rain Barrels (or Cisterns) are containers that collect roof runoff during
                       storm events  and can either  release or re-use the rainwater during dry
                       periods.
                       Rooftop  Disconnection  has   downspouts  discharge  to  pervious
                       landscaped areas and lawns instead of directly into storm drains.  It can
                       also  model  roofs with directly connected  drains  that  overflow onto
                       pervious areas.
                       Vegetative Swales are channels or depressed areas with sloping sides
                       covered with  grass  and  other vegetation.  They  slow  down  the
                       conveyance of collected runoff and  allow it more time to infiltrate the
                       native soil beneath it.
Bio-retention  cells, infiltration trenches, and permeable pavement systems can contain optional
drain systems in their gravel storage beds to convey excess captured runoff off of the site and
prevent the unit from flooding. They can also have an impermeable floor or liner that prevents any
infiltration into  the  native soil from  occurring.  Infiltration trenches and  permeable  pavement
systems can also be subjected to a decrease in hydraulic conductivity overtime due to clogging.
Although some LID  practices can also provide significant pollutant reduction benefits, at this time
SWMM only models the reduction in  runoff mass load resulting from the reduction in runoff flow
volume.
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There are two different approaches for placing LID controls within a subcatchment:
•   place one or more controls in an existing subcatchment that will displace an equal amount of
    non-LID area from the subcatchment
•   create a new subcatchment devoted entirely to just a single LID practice.

The first approach allows a mix of LIDs to be placed into a  subcatchment, each treating  a
different portion of the runoff generated from the non-LID fraction of the subcatchment. Note that
under this option the subcatchment's LIDs act in parallel - it is not possible to make them act in
series (i.e., have the outflow from one LID control become the inflow to another LID). Also, after
LID placement the subcatchment's  Percent  Impervious  and  Width  properties may  require
adjustment to  compensate  for the amount  of original subcatchment area that has now been
replaced by LIDs (see Figure 3-6 below). For example, suppose that a subcatchment which is
40% impervious has 75% of that area converted to a permeable pavement LID. After the LID is
added  the subcatchment's  percent  imperviousness  should  be changed to the  percent  of
impervious area remaining divided by the  percent of non-LID area remaining. This works out to (1
- 0.75)*40 / (100 - 0.75*40) or 14.3 %.
                                 Width
                                                                    Width
       Before LIDs
                                   After LIDs
         Figure 3-6  Adjustment of subcatchment parameters after LID placement

Under this first approach the runoff available for capture by the subcatchment's LIDs is the runoff
generated from its impervious area.  If the option to re-route some fraction of this runoff to the
pervious area is exercised, then only the remaining  impervious runoff (if any) will be available for
LID treatment. Also note that green roofs and roof disconnection only treat the precipitation that
                                          71

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falls  directly  on  them  and  do not  capture  runoff  from other impervious  areas  in  their
subcatchment.

The second approach allows LID controls to be strung along in series and also allows runoff from
several  different upstream  subcatchments to be routed onto the  LID subcatchment. If these
single-LID subcatchments are carved out of existing  subcatchments, then  once again some
adjustment of the Percent Impervious, Width and also  the Area properties of the latter may be
necessary. In addition, whenever an LID occupies the entire subcatchment the values assigned
to the subcatchment's standard surface properties (such as imperviousness, slope, roughness,
etc.) are overridden by those that pertain to the LID unit.

Normally both surface and drain outflows from LID units are routed to the same outlet location
assigned to the parent subcatchment.  However one can  choose to return all LID outflow to the
pervious area of the parent subcatchment and/or route the drain outflow to a separate designated
outlet. (When both of these options are chosen,  only the  surface outflow  is returned to the
pervious sub-area.)
3.4    Computational Methods

SWMM  is a  physically based,  discrete-time  simulation  model.  It employs principles of
conservation  of  mass,  energy,  and  momentum  wherever  appropriate.  This  section  briefly
describes the methods SWMM uses to model stormwater runoff quantity and quality through the
following physical processes:

       •   Surface Runoff                           •   Infiltration
       •   Groundwater                            •   Snowmelt
       •   Flow Routing                            •   Surface Ponding
       •   Water Quality Routing
3.4.1   Surface Runoff

The conceptual view of surface runoff used by SWMM is illustrated in  Figure 3-7 below.  Each
subcatchment surface is treated as a nonlinear reservoir. Inflow comes from precipitation and any
designated  upstream  subcatchments.  There  are  several  outflows,  including  infiltration,
evaporation, and  surface runoff. The  capacity of this "reservoir" is  the  maximum depression
storage, which  is the  maximum surface storage provided  by ponding,  surface  wetting,  and
interception. Surface runoff per unit area, Q, occurs only when the depth  of  water in the
"reservoir" exceeds the maximum depression storage, ds, in  which case the outflow is given by
Manning's equation. Depth of water over the subcatchment (d) is continuously updated with time
by solving numerically a water balance equation over the subcatchment.
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              Precipitation
                     V
Evaporation
     A
                                                                      Runoff
                            Infiltration
                      Figure 3-7 Conceptual view of surface runoff
3.4.2    Infiltration

Infiltration is the  process of rainfall penetrating the ground surface into the unsaturated soil zone
of pervious subcatchments areas.  SWMM offers four choices for modeling infiltration:

Morton's Method
This method is based on empirical observations showing that infiltration  decreases exponentially
from an initial maximum rate to some minimum rate over the course of a long rainfall event. Input
parameters required by this method include the maximum and minimum  infiltration rates, a decay
coefficient that  describes  how fast  the  rate decreases over  time, and a time it takes  a fully
saturated soil to completely dry.

Modified Morton Method
This is a modified version  of the classical Morton  Method that uses the cumulative infiltration in
excess  of the minimum rate as  its state variable (instead of time along the Morton curve),
providing a more accurate infiltration estimate when low rainfall intensities occur. It uses the same
input parameters as does the traditional Morton Method.

Green-Ampt Method
This method for modeling infiltration  assumes that a sharp wetting front exists in the soil column,
separating  soil with some  initial moisture content below from saturated soil  above. The input
parameters required are the initial  moisture deficit of the soil, the soil's hydraulic conductivity, and
the  suction head at the wetting front. The recovery rate of moisture deficit during dry periods is
empirically related to the hydraulic conductivity.

Modified Green-Ampt Method
This method modifies the original  Green-Ampt procedure by not depleting moisture deficit in the
top  surface layer of soil during initial periods of low rainfall as was done in the original method.
This change  can produce  more realistic infiltration behavior for storms with  long  initial periods
where the rainfall intensity is below the soil's saturated hydraulic conductivity.
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Curve Number Method
This approach is adopted from the NRCS (SCS) Curve Number method for estimating runoff. It
assumes that the total infiltration capacity of a soil can be found from the soil's tabulated Curve
Number. During  a rain event this capacity is depleted as a function of cumulative rainfall and
remaining capacity. The  input  parameters for this method are the curve number and the time it
takes a fully saturated soil to completely dry.

SWMM  also allows the infiltration recovery rate to be adjusted  by a fixed amount on a monthly
basis to account for seasonal  variation in such  factors as evaporation rates and groundwater
levels. This optional monthly soil recovery pattern is specified as part of a project's Evaporation
data.
3.4.3   Groundwater

Figure 3-8 is a definitional sketch of the two-zone groundwater model that is used in SWMM. The
upper zone is unsaturated with a variable moisture content of 6. The lower zone is fully saturated
and therefore its moisture content  is  fixed at the soil porosity 4>. The fluxes shown in the figure,
expressed as volume per unit area  per unit time, consist of the following:
         Upper
          Zone
          Zone
                        A-    /r
                KXXXXXXXXXXXXI p
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After computing the water fluxes that exist during a given time step, a mass balance is written for
the change in water volume stored in each zone so that a new water table depth and unsaturated
zone moisture content can be computed for the next time step.


3.4.4   Snowmelt

The snowmelt routine in SWMM is a part of the runoff modeling process. It updates the state of
the snow packs associated with each subcatchment by accounting for snow accumulation, snow
redistribution  by areal  depletion  and  removal operations,  and snow melt via heat  budget
accounting. Any snowmelt coming off the pack is treated as an additional rainfall input onto the
subcatchment.

At each runoff time step the following computations are made:
    l.  Air temperature and melt coefficients are updated according to the calendar date.
    2.  Any precipitation that falls as snow is added to the snow pack.
    3.  Any excess snow depth on the plowable area of the pack is redistributed according to the
       removal parameters established for the pack.
    4.  Areal coverage of snow on the  impervious and pervious areas of the pack is reduced
       according to the Areal Depletion Curves defined  for the study area.
    5.  The amount of snow in the pack that melts to liquid water is found using:
           a.  a heat budget equation for  periods with rainfall, where melt rate increases with
               increasing air temperature, wind speed, and rainfall intensity
           b.  a degree-day equation for  periods with no rainfall, where melt  rate equals the
               product of a melt  coefficient and the difference between the air temperature and
               the pack's base melt temperature.
    6.  If no melting occurs, the pack temperature is adjusted up or down based on the product
       of the difference between current and past air temperatures and  an adjusted melt
       coefficient. If melting occurs, the temperature of the pack is increased by the  equivalent
       heat content of the melted snow, up to the base melt temperature. Any remaining melt
       liquid beyond this is available to runoff from the pack.
    7.  The available snowmelt is then  reduced by the amount  of free water holding capacity
       remaining in the pack. The remaining  melt is treated the same as an additional rainfall
       input onto the subcatchment.
3.4.5   Flow Routing

Flow routing  within a conduit  link in SWMM is  governed by the conservation  of mass and
momentum equations for gradually varied, unsteady flow (i.e., the Saint Venant flow equations).
The SWMM user has a choice on the level of sophistication used to solve these equations:
    •   Steady Flow Routing
    •   Kinematic Wave Routing
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    •   Dynamic Wave Routing

Each  of these routing methods employs the Manning equation to relate flow rate to flow depth
and bed (or friction) slope. For user-designated Force Main conduits, either the Hazen-Williams
or Darcy-Weisbach equation can be used when pressurized flow occurs.

Steady Flow Routing

Steady Flow routing represents the simplest type  of routing  possible (actually no routing) by
assuming  that within each computational time step flow is uniform and steady. Thus it simply
translates  inflow hydrographs at the upstream end of the conduit to the downstream end, with no
delay or change in shape. The normal flow equation is used to relate flow rate to flow area (or
depth).

This type of routing  cannot account for channel storage, backwater effects, entrance/exit  losses,
flow reversal or pressurized flow. It can only be used with dendritic conveyance networks, where
each  node has only a single outflow link (unless the node is a divider in which case two  outflow
links are required). This form of routing is insensitive to the time step employed and is really only
appropriate for preliminary analysis using long-term continuous simulations.

Kinematic Wave Routing

This routing method solves the continuity equation along with a simplified form of the momentum
equation in each conduit. The latter assumes that the slope of the water surface equal the slope
of the conduit.

The maximum flow that can be conveyed through a conduit is the full normal flow value. Any flow
in excess  of this entering the inlet node is either lost from the system or can pond atop the inlet
node  and be re-introduced into the conduit as capacity becomes available.

Kinematic wave routing allows  flow  and area to vary both  spatially  and temporally within a
conduit. This  can result in attenuated and delayed  outflow  hydrographs as  inflow  is  routed
through the  channel.  However  this form  of routing  cannot  account for  backwater effects,
entrance/exit losses, flow reversal, or pressurized flow, and is also restricted to dendritic network
layouts. It  can usually maintain numerical stability with moderately large time steps, on the order
of 1 to 5  minutes.  If the aforementioned  effects  are not expected to be significant then  this
alternative can be an accurate and efficient routing method, especially for long-term simulations.

Dynamic Wave Routing

Dynamic Wave routing solves the complete one-dimensional Saint Venant flow equations  and
therefore  produces  the most theoretically accurate  results.  These equations  consist  of the
continuity and momentum equations for conduits and a volume continuity equation at nodes.

With  this  form of routing it is possible to  represent pressurized flow when a  closed conduit
becomes full, such that flows  can exceed the full normal flow value. Flooding occurs when the
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water depth at a node exceeds the maximum available depth, and the excess flow is either lost
from the system or can pond atop the node and re-enter the drainage system.

Dynamic wave  routing can account for channel storage, backwater, entrance/exit losses, flow
reversal,  and  pressurized flow. Because it couples together the solution for both water levels at
nodes and flow in conduits it can be applied to any general network layout, even those containing
multiple downstream diversions and loops. It is the method of choice for systems subjected to
significant backwater effects due to downstream flow restrictions and with flow regulation  via
weirs and orifices. This generality comes at a price of having to use much smaller time steps, on
the order of a thirty seconds or less (SWMM can automatically reduce the user-defined maximum
time  step as needed to maintain numerical stability).


3.4.6  Ponding and Pressurization

Normally in flow routing,  when the flow into a junction exceeds the  capacity of the system to
transport it further downstream, the excess volume overflows the system and is lost. An option
exists to have instead the excess volume be stored atop the junction, in a ponded  fashion, and be
reintroduced into the system as capacity permits. Under Steady and Kinematic Wave flow routing,
the ponded water is stored simply  as an excess volume. For Dynamic Wave routing,  which is
influenced by the water depths maintained at nodes, the excess volume is assumed to pond over
the node with a  constant surface  area. This amount of surface  area  is an input parameter
supplied for the junction.

Alternatively,  the  user may wish to represent the surface  overflow system  explicitly.  In open
channel systems this can include  road  overflows at  bridges  or culvert crossings as  well as
additional floodplain  storage  areas.  In  closed  conduit systems, surface overflows  may  be
conveyed down streets, alleys, or other surface routes to the next available stormwater inlet or
open channel. Overflows  may also be impounded  in surface depressions such as parking lots,
back yards or other areas.

In  sewer systems with pressurized  pipes and force mains the hydraulic  head at junction nodes
can  at times  exceed the ground elevation  under Dynamic Wave routing. This  would  normally
result in an overflow which, as described above, can either be lost or ponded. SWMM allows the
user to specify an additional "surcharge" depth for junction nodes that lets them pressurize and
prevents  any  outflow until this additional depth is  exceeded. If both ponding  and pressurization
are specified for a node  ponding takes precedence and the surcharge depth  is ignored. Neither
ponding nor pressurization applies to storage nodes.


3.4.7  Water Quality Routing

Water quality routing within conduit links assumes that the conduit behaves as a continuously
stirred tank reactor (CSTR). Although a plug flow reactor assumption might be more realistic, the
differences will be small if the  travel time through the conduit is on the same order as the routing
time  step. The concentration of a constituent exiting the conduit at the end of a time step is found
by integrating the conservation of mass equation,  using average values for quantities that might
change over the time step such as flow rate  and conduit volume.
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Water quality modeling within storage unit nodes follows the same approach used for conduits.
For other types of nodes that have no volume, the quality of water exiting the node is simply the
mixture concentration of all water entering the node.

The pollutant concentration in both a conduit and a storage node will be reduced by a first-order
decay reaction if the pollutant's first-order decay coefficient is not zero.


3.4.8   LID Representation

LID controls are represented by a combination of vertical layers whose properties are  defined on
a per-unit-area  basis. This allows LIDs of the same design  but differing  area coverage to easily
be placed within different subcatchments of a study area. During a simulation SWMM  performs a
moisture balance that keeps track of how much water moves between and is stored within each
LID layer. As an example, the layers used to model a bio-retention cell and the flow pathways
between them are shown in Figure 3-9. The various possible layers consist of the following:
            Rainfall   ET
Overflow           * f
                                                          Runon
,— <
^
Surface Layers
/
i
Soil Layer '
Storage Layer
Inflltratk
B
-0-
Percolat
4
                                                          on
                        Underdrain
                                                  Infiltration

                Figure 3-9 Conceptual diagram of a bio-retention cell LID

    The Surface Layer corresponds to the ground (or  pavement) surface that receives direct
    rainfall and runon from upstream land areas, stores excess inflow in depression storage, and
    generates surface outflow that either enters the drainage system or flows onto downstream
    land areas.
    The Pavement Layer is the layer of porous concrete or asphalt used in continuous permeable
    pavement systems, or is the paver blocks and filler material used in modular systems.
    The So;7 Layer is the engineered soil mixture used in bio-retention cells to support vegetative
    growth. It can also be a sand layer placed beneath a pavement layer to provide bedding and
    filtration.
    The Storage Layer is a bed of crushed rock or gravel that provides storage in bio-retention
    cells, porous pavement, and infiltration trench systems. For a rain barrel it is simply the barrel
    itself.
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•   The Drain  System conveys water out of the gravel  storage  layer of bio-retention  cells,
    permeable  pavement systems, and  infiltration trenches (typically with slotted  pipes) into a
    common outlet pipe or chamber. For rain barrels it is simply the drain valve at the bottom of
    the barrel while for rooftop disconnection it is the roof gutter and downspout system.
•   The Drainage Mat Layer is a  mat or plate placed between the soil media and the  roof in a
    green  roof whose purpose  is to convey any water that drains through the soil layer off of the
    roof.
Table 3-3  indicates which combination of layers applies to each type of LID (x means required, o
means optional).
                Table 3-3 Layers used to model different types of LID units
LID Type
Bio-Retention Cell
Rain Garden
Green Roof
Permeable Pavement
Infiltration Trench
Rain Barrel
Roof Disconnection
Vegetative Swale
Surface
X
X
X
X
X

X
X
Pavement



X




Soil
X
X
X
0




Storage
0


X
X
X


Drain
0


0
0
X
X

Drainage Mat


X





All of the LID controls provide some amount of rainfall/runoff storage and evaporation of stored
water (except for rain barrels). Infiltration into native soil occurs in vegetative swales and can also
occur in bio-retention cells, rain  gardens, permeable  pavement systems, and infiltration trenches
if those systems do not employ an optional impermeable bottom liner.  Infiltration trenches and
permeable  pavement systems can also be subjected to clogging. This reduces their hydraulic
conductivity overtime proportional to the cumulative hydraulic loading they receive.

The  performance  of the LID  controls placed in a subcatchment is reflected in the overall runoff,
infiltration,  and evaporation  rates computed  for  the  subcatchment as  normally reported by
SWMM. SWMM's Status Report also contains a section entitled LID Performance Summary that
provides an overall water balance  for each  LID control  placed  in each subcatchment.  The
components of this water balance include total inflow, infiltration,  evaporation, surface runoff,
drain flow and initial and final stored volumes, all expressed  as inches (or mm) over the LID's
area. Optionally, the entire time  series  of flux rates and moisture levels for a selected LID control
in a given subcatchment can be written to a tab delimited text  file for easy viewing and graphing
in a spreadsheet program (such  as Microsoft Excel).
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                    CHAPTER 4 - SWMM'S MAIN WINDOW
This chapter discusses the essential features of SWMM's workspace. It describes the main menu
bar, the tool and status bars, and the three windows used most often - the Study Area Map, the
Browser, and the Property Editor. It also shows how to set program preferences.
4.1
Overview
The EPA SWMM  main window  is pictured below.  It consists  of the  following user  interface
elements: a Main Menu, several Toolbars, a Status Bar, the Study Area Map window, a Browser
panel, and a Property Editor window.  A description of each of these elements is provided in the
sections that follow.
  I! SWMM 5,1 - Examplel.inp
   File  Edit V -.    !-n= i  ;
   . D & y d; % M •
                                                                                  £2
   Project Map
    Project/Map Browser
      Hydrology
    j • Hydraulics
    \   • • Nodes
    ;   4 Links
    i   i  !••• Conduits
    ;   \  :•••• Pumps
    \   \  !••- Orifices
    \   \  L Weirs
           Outlets
  i Conduits
  I4
  J5
  I6
  J7
  |s
  110
                                         Main Menu
S
                                                                       H
                                                                            Toolbars
                                                         Conduitl
                                                                  Property Editor
                                                                                IS!
                                                         Property
                                                                      Value
                                                         Name         1
                                                         Inlet Node      9
                                                         Outlet Node     10
                                                         Description
                                                         Tag
                                                         Shape         CIRCULAR
                                                         Max. Depth     1,5
                                                         Length        400

                                                         User-assigned name of Conduit
   Auto-Length: Off  -   Offsets: Depth  -r   Flow Units; CFS  *  E'J   Zoom Level: 100%    XV: 3656,915,10026.596
                                             80

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4.2
Main Menu
The Main Menu located across the top of the EPA SWMM main window contains a collection of
menus used to control the program. These include:
    •   File Menu
    •   Edit Menu
    •   View Menu
    •   Project Menu
    •   Report Menu
    •   Tools Menu
    •   Window Menu
    •   Help Menu

File Menu

The File Menu contains commands for opening and saving data files and for printing:
    Command
             Description
    New            Creates a new SWMM project
    Open            Opens an existing project
    Reopen          Reopens a recently used project
    Save            Saves the current project
    Save As         Saves the current project under a different name
    Export           Exports study area map to a file in a variety of formats;
                    Exports current results to a Hot Start file;
                    Exports the current result's Status/Summary reports
    Combine         Combines two Routing Interface files together
    Page Setup      Sets page margins and orientation for printing
    Print Preview     Previews a printout of the currently active view (map, report,
                    graph, or table)
    Print            Prints the current view
    Exit             Exits EPA SWMM
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Edit Menu

The Edit Menu contains commands for editing and copying:
    Command
Description
    Copy To          Copies the currently active view (map, report, graph or table)
                     to the clipboard or to a file
    Select Object      Enables the user to select an object on the map
    Select Vertex      Enables the user to select the vertex of a subcatchment or
                     link
    Select Region     Enables the user to delineate a region on the map for
                     selecting multiple objects
    Select All         Selects all objects when the map is the active window or all
                     cells of a table when a tabular report is the active window
    Find Object       Locates a specific object by name on the map
    Edit Object        Edits the properties of the currently selected  object
    Delete Object      Deletes the currently selected object
    Group Edit        Edits a property for the  group of objects that fall within the
                     outlined region of the map
    Group Delete      Deletes a group of objects that fall within the outlined region
                     of the map

View Menu

The View Menu contains commands for viewing the Study Area Map:
    Command
 Description
    Dimensions        Sets reference coordinates and distance units for the study
                      area map
    Backdrop          Allows a backdrop image to be added, positioned, and
                      viewed behind the map
    Pan               Pans across the map
    Zoom In           Zooms in on the map
    Zoom Out          Zooms out on the map
    Full Extent         Redraws the  map at full extent
    Query             Highlights objects on the map that meet specific criteria
    Overview          Toggles the display of the Overview Map
    Objects            Toggles display of classes of objects on the map
    Legends           Controls display of the map legends
    Toolbars           Toggles display of toolbars
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Project Menu

The Project menu contains commands related to the current project being analyzed:
    Command
Description
    Summary
    Details
    Defaults
    Calibration Data
    Add a New Object
    Run Simulation
Lists the number of each type of object in the project
Shows a detailed listing of all project data
Edits a project's default properties
Registers files containing calibration data with the project
Adds a new object to the project
Runs a simulation
Report Menu

The Report menu contains commands used to report analysis results in different formats:
    Command
Description
    Status
    Summary
    Graph
    Table
    Statistics
    Customize
Displays a status report for the most recent simulation run
Displays summary results in tabular form
Displays simulation results in graphical form
Displays simulation results in tabular form
Displays a statistical analysis of simulation results
Customizes the display style of the currently active graph
Tools Menu

The  Tools menu contains commands used to configure program preferences, study area map
display options, and external add-in tools:
    Command
    Program
    Preferences
    Map Display
    Options
    Configure Tools
Description
Sets program preferences, such as font size, confirm
deletions, number of decimal places displayed, etc.
Sets appearance options for the Map, such as object size,
annotation, flow direction arrows, and back-ground color
Adds, deletes, or modifies external add-in tools
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Window Menu

The Window Menu contains commands for arranging and selecting windows within the SWMM
workspace:

    Command          Description
    Cascade            Arranges windows in cascaded style, with the study area
                       map filling the entire display area
    Tile                Minimizes the study area map and tiles the remaining
                       windows vertically in the display area
    Close All            Closes all open windows except for the study area map
    Window List         Lists all open windows; the currently selected window has
                       the focus and is denoted with a check mark
Help Menu

The Help Menu contains commands forgetting help in using EPA SWMM:

    Command           Description
    Help Topics          Displays the Help system's Table of Contents
    How Do I             Displays a list of topics covering the most common
                        operations
    Measurement Units   Shows measurement units for all of SWMM's parameters
    Error Messages       Lists the meaning of all error messages
    Tutorial              Presents a short tutorial introducing the user to EPA
                        SWMM
    About               Lists information about the version of EPA SWMM being
                        used
4.3    Toolbars

Toolbars provide shortcuts to commonly used operations. There are three such toolbars:
    •   Standard Toolbar
    •   Map Toolbar
    •   Object Toolbar

Individual toolbars can be made visible or invisible by selecting View » Toolbars from the Main
Menu.
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The Standard Toolbar contains buttons for the following commonly used commands:
    0    Creates a new project (File » New)
    \jSr    Opens an existing project (File » Open)
    y    Saves the current project (File » Save)
    ^    Prints the currently active window (File » Print)
    Hd    Copies selection to the clipboard or to a file (Edit » Copy To)
    J4    Finds a specific object on the Study Area Map (Edit » Find Object)
    ?{]    Makes a visual query of the study area map (View » Query)
    i®    Toggles the display of the Overview Map (View » Overview)
    ^    Runs a simulation (Project » Run Simulation)
    HI    Displays a run's Status or Summary reports (Report » Status and Report
          » Summary appear in a dropdown menu)
    Ny    Creates a profile plot of simulation results (Report » Graph » Profile)
    H£    Creates a time series plot of simulation results (Report » Graph » Time
          Series)
    HI]    Creates a time series table of simulation results (Report » Table)
    |£    Creates a scatter plot of simulation results (Report » Graph » Scatter)
    2    Performs a statistical analysis of simulation results (Report » Statistics)
    Hf1    Modifies display options for the currently active view (Tools » Map Display
          Options or Report » Customize)
    3^,    Arranges windows in cascaded style, with the study area map filling the
          entire display area (Window » Cascade)
The Map Toolbar contains the following buttons for viewing the study area map:
    ^    Selects an object on the map  (Edit » Select Object)
    [^    Selects link or subcatchment vertex points (Edit » Select Vertex)
    jj£    Selects a region on the map (Edit » Select Region)
    O    Pans across the map (View » Pan)
    <±^    Zooms in on the map (View » Zoom In)
    G^    Zooms out on the map (View  » Zoom Out)
    H    Draws map at full extent (View » Full Extent)
    ^    Measures a length or area on the map
                                          85

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The  Object Toolbar contains buttons for adding visual objects to  a  project via the study area
map.
     9?   Adds a rain gage to the map.
     ^   Adds a subcatchment to the map

     O   Adds a junction node to the map
     V   Adds an outfall node to the map
     O   Adds a flow divider node to the map
     bid   Adds a storage unit node to the map
     *-<   Adds a conduit link to  the map
     (71   Adds a pump link to the map
     •H   Adds an orifice link to  the map
     Q   Adds a weir link to the map
     3   Adds an outlet link to the map
     T   Adds a text label to the map



4.4    Status Bar

The Status Bar appears at the bottom of SWMM's Main Window and is divided into six sections:
 Auto-Length: Off  '   Offsets: Depth  "  Flow Units: CFS  "   |   Zoom Level: 100%   X,Y: -1103,723,53,191
Auto-Length
Indicates whether the  automatic computation of conduit  lengths and subcatchment areas is
turned on or off. The setting can be changed by clicking the drop down arrow.

Offsets
Indicates whether the positions of links above the invert of their connecting nodes are expressed
as a Depth above the node invert or as the Elevation of the offset. Click the drop down arrow to
change this option. If changed, a dialog box will appear asking if all existing offsets in the current
project should be changed or not (i.e., convert Depth  offsets to Elevation  offsets or Elevation
offsets to Depth offsets, depending on the option selected)

Flow Units
Displays the current flow units that are in  effect. Click the drop down  arrow to change the choice
of flow units. Selecting a US flow unit  means that all other quantities will  be expressed in US
units, while choosing a metric flow unit will force all quantities to be expressed in metric units. The
units of previously entered data are not automatically adjusted if the unit system is changed.
                                           86

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Run Status

  I     results are not available because no simulation has been run yet.
-|     results are up to date.
•-'I     results are out of date because project data have changed.
^|     results are not available because the last simulation had errors.

Zoom Level
Displays the current zoom level for the map (100% is full-scale).

XY Location
Displays the map coordinates of the current position of the mouse pointer.
4.5    Study Area Map

The  Study Area  Map (shown  below) provides a  planar  schematic diagram  of  the  objects
comprising a drainage system. Its pertinent features are as follows:
                       Study Area Map
       The location of objects and  the  distances between them  do not necessarily have to
       conform to their actual physical scale.
       Selected properties of these  objects, such as water quality at nodes or flow velocity in
       links, can  be displayed by using different colors. The color-coding is  described  in a
       Legend, which can be edited.
                                           87

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       New objects can be directly added to the  map and existing objects can  be selected for
       editing, deleting, and repositioning.
       A backdrop drawing (such as a street or topographic  map) can be  placed behind the
       network map for reference.
       The map can be zoomed to any scale and panned from one position to another.
       Nodes and links can be drawn at different  sizes, flow direction arrows added, and object
       symbols, ID labels and numerical property values displayed.
       The map can be printed, copied onto the Windows clipboard, or exported as a DXF file or
       Windows metafile.
4.6    Project Browser

The  Project Browser panel (shown below) appears when the Project tab on the left panel  of
SWMM's main window is selected. It provides access to all of the data objects in a project. The
vertical sizes of the list boxes in the browser can be adjusted by using the splitter bar located just
below the upper list box. The width of the Browser panel can be adjusted by using the splitter bar
located along its right edge.
                              The upper list box displays the various categories of data objects
                              available to a SWMM project. The lower list box lists the name of
                              each individual object of the currently selected data category.
Project  Map

 ;•••• Climatology
   Hydrology
 j Hydraulics
 I    • Nodes
 !   * - Links
 |   |   !•••• Conduits
 I   !   !•••• Pumps
 |   i   ;•••• Orifices
 |   j   [..-Weirs
 \   I   i.- Outlets
          II
 Conduits
 [ 10001

  10003
  10004
  10005
  10006
  10007
The buttons between the two list boxes are used as follows:
 *  adds a new object
 ~  deletes the selected object
 &  edits the selected object
 "fr  moves the selected object up one position
 ®  moves the selected object down one position
 z+  sorts the objects in ascending order

Selections  made in  the  Project Browser are coordinated  with
objects highlighted on the Study Area Map, and vice versa. For
example,  selecting  a conduit in  the Browser will cause  that
conduit to be  highlighted on the map, while  selecting it  on the
map will cause it to become the selected object in the Browser.
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4.7    Map Browser

The  Map Browser panel  (shown below) appears when the Map tab  on the  left panel of the
SWMM's main window is  selected. It controls the mapping themes and time periods viewed on
the Study Area Map. The width of the Map Browser panel can be adjusted by using the splitter
bar located along its right edge.  The Map Browser consists of the following three panels that
control what results are displayed  on the map:

  Project! Map
   Themes                  The Themes panel selects  a set of variables to view in  color-
   Subcatchments            coded fashion on the Map.
    Area            w

   Nodes
    Invert           T

   Links
    Flow           -r
   Time Period               j^g  jjme  perjoc| panel  selects which  time  period  of  the
   Date                     simulation results are viewed on the Map.
    06/27/2002
   Time of Day
    00:15:00
   Elapsed Time
    0,00:15:00
   Animator
           _               The Animator panel controls the animated display of the Study
                            Area Map and all Profile Plots overtime.
                                          89

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The Themes panel of the Map Browser is used to select a thematic variable to view in color-
coded fashion on the Study Area Map.

  Themes
  Sub catchments        Subcatchments - selects the theme to display for the subcatchment
               w      areas shown on the Map.
  Nodes               Nodes - selects the theme to display for the drainage system nodes
  Invert        -r      shown on the Map.
  Links
                      Links - selects the theme to display for the drainage system links
                      shown on the Map.

The Time Period panel of the Map Browser allows is used to select a time period in which to view
computed results in thematic fashion on the Study Area Map.

  Time Period
  Date
  06 ,-'27 ,-'2002      -r     Date - selects the day for which simulation results will be  viewed.
   Imeo   ay            Time of Day - selects the time of the current day (in
     '  '          T     hours:minutes:seconds) for which simulation results will be viewed.
   <  \             r
  Elapsed Time           Elapsed Time - selects the elapsed time from the start of the
   0,01:00:00        I     simulation (in days.hours:minutes:seconds) for which results will be
                       viewed.

The Animator panel of the Map Browser contains controls for animating the Study Area Map and
all Profile  Plots through time i.e.,  updating  map color-coding and hydraulic  grade line profile
depths as  the simulation time clock is automatically moved forward or back. The meaning of the
control buttons are as follows:

  Animator               M Returns to the starting period.
   M  4  H  *•          ^ Starts animating backwards in time
         pi              H Stops the animation
                         ^ Starts animating forwards in time
                       The slider bar is used to adjust the animation speed.
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4.8    Property Editor

The Property Editor (shown to the right) is used to edit
the properties of data  objects that can appear on the
Study Area Map. It is invoked when one of these objects
is selected (either on the Map or in the Project Browser)
and double-clicked or when the Project Browser's Edit
button  & is clicked.

Key features of the Property Editor include:
    •   The Editor is a grid with two  columns - one for
       the property's name and the other for its value.
    •   The columns can  be re-sized  by re-sizing the
       header at the top of the Editor with the mouse.
    •   A hint area  is  displayed  at the  bottom of the
       Editor with  an expanded description  of the
       property being  edited. The size of this area can
       be adjusted by dragging the splitter bar located
       just above it.
Conduit 10 H
Property
Name
Inlet Node
Outlet Node
Description
Tag
Shape
Max. Depth
Length
Roughness
Inlet Offset
Value
10
17 ; 	 [
18


IGRCULAR ...J
2
400
0.01
0
Click to edit the conduit's cross
section geometry

       The Editor window can be moved and re-sized via the normal Windows operations.
       Depending on the property, the value field can be one of the following:
       o   a text box in which you enter a value
       o   a dropdown combo box from which you select a value from a list of choices
       o   a dropdown combo box in which you can enter a value or select from a list of choices
       o   an ellipsis button which you  click to bring up a specialized editor.
       The field  in the Editor that currently has the focus will have a focus rectangle drawn
       around it.
       Both the mouse and the Up and Down arrow keys on the keyboard can be used to move
       between property fields.
       The Page Up key can be used to select the  previous object of the same type (as listed in
       the Project Browser) into the Editor, while the Page Down key will select the next object
       of the same type into the Editor.
       To  begin editing the property with the focus, either begin typing a value or hit the Enter
       key.
       To  have the program  accept edits made in a property field, either press the Enter key or
       move to another property. To cancel the edits, press the Esc key.
       The Property Editor can be hidden by clicking the button in the  upper right corner of its
       title bar.
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4.9    Setting Program Preferences

Program  preferences allow one  to customize  certain  program  features. To  set program
preferences, select Program Preferences from the Tools  menu. A Preferences dialog form will
appear containing two tabbed  pages - one for  General Preferences and one for Numerical
Precision.
Preferences

General Options
m
Numerical Precision
[3 Blinking Map Highlighter
G/] Flyover Map Labeling
(3 Confirm Deletions
O Automatic Backup File
[3 Tab Delimited Project File
0 Report Elapsed Time by Default
0 Prompt to Save Results
D Clear File List
Style Theme
Windows w

| OK



Cancel Help





Preferences

| General Options







Numerical Precision
gii

Select number of decimal places for
computed results^
Subcatch Parameter
Precipitation -r
Node Parameter
Depth w
Link Parameter
Flow T

OK



Cancel

Decimals
2 ;
Decimals
e ;
Decimals
2 *



Help






The following preferences can be set on the General Preferences page of the Preferences dialog:
    Preference
Description
    Blinking Map Highlighter
    Flyover Map Labeling
    Confirm Deletions
    Automatic Backup File
Check to make the selected object on the study area map
blink on and off
Check to display the ID label and current theme value in a
hint-style box whenever the mouse is placed over an object
on the study area  map
Check to display a confirmation dialog box before deleting
any object
Check to save a backup copy of a newly opened project to
disk named with a .bak extension
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    Report Elapsed Time by
    Default
    Prompt to Save Results
    Clear File List
    Style Theme
Check to use elapsed time (rather than date/time) as the
default for time series graphs and tables.
If left unchecked then simulation results are automatically
saved to disk when the current project is closed. Otherwise
the user will be asked if results should be saved.
Check to clear the list of most recently used files that appears
when  File » Reopen is selected from the Main Menu
Selects a color theme to use for SWMM's user interface (see
below for some examples)
Preferences
Genera! Options : Numerical Precision 1
i J Blinking Map Highlighter i
| •/ Flyover Map Labeling j
i V Confirm Deletions i
i Automatic Backup File i
| J Tab Delimited Project File |
i J Report Elapsed Time by Default i
j / Prompt to Save Results j
I Clear File List j
Style Theme; i
Windows T i
OK • ' Cancel | [ Help |

n^^^^^^^^^^^^jfpreference, ' ' ' ' X
1 1 General Options Numerical Precision
i i V Blinking Map Highlighter
i i */ Flyover Map Labeling
i i •>/ Confirm Deletions
1 1 Automatic Backup File
1 1 
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                CHAPTER 5 -WORKING WITH PROJECTS
Project files contain all of the information used to model a study area.  They are usually named
with a .INP extension. This section describes how to create, open, and save EPA SWMM projects
as well as setting their default properties.

5.1     Creating a New Project
To create a new project:
   l .  Select File » New from the Main Menu or click 0 on the Standard Toolbar.
   2 .  You will be prompted to save the existing project (if changes were made to it) before the
       new project is created.
   3 .  A new, unnamed  project is created with all options set to their default values.
A new project is automatically created whenever EPA SWMM first begins.
       If you are going to use a backdrop image with automatic area and length calculation, then
       it is recommended that you set the map dimensions immediately after creating the new
       project (see Section 7.2 Setting the Map's Dimensions).
5.2    Opening an Existing Project
To open an existing project stored on disk:
    l .  Either select File » Open from the Main Menu or click & on the Standard Toolbar.
    2 .  You will be prompted to save the current project (if changes were made to it).
    3 .  Select the file to open from the Open File dialog form that will appear.
    4 .  Click Open to open the selected file.
To open a project that was worked on recently:
    l .  Select File » Reopen from the Main Menu.
    2 .  Select a file from the list of recently used files to open.

5.3    Saving a Project
To save a project  under its current name either select File » Save from the  Main Menu or click
H on the Standard Toolbar.
To save a project  using a different name:
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    l.  Select File » Save As from the Main Menu.
    2.  A standard File Save dialog form will appear from  which you can select the folder and
        name that the project should be saved under.

5.4     Setting Project Defaults
Each project has a set of default values that are used unless overridden  by the SWMM  user.
These values fall into three categories:
    1.   Default ID labels (labels used to identify nodes and links when they are first created)
    2.   Default subcatchment properties (e.g., area, width, slope, etc.)
    3.   Default node/link properties (e.g., node invert, conduit length, routing method).
To set default values for a project:
    l.  Select Project » Defaults from the Main Menu.
    2.  A Project  Defaults  dialog will appear with  three pages, one  for each category listed
        above.
 Project Defaults
   ID Labels  I Sub catchments  Nodes/Links
   Object
   ID Prefix
   Rain Gages
   Sub catchments
   Junctions
   Outfalls
   Dividers
   Storage Units
   Conduits
   Pumps
   Regulators
   ID Increment
  [I] Save as defaults for all new projects
       OK
Cancel
Help
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    3.  Check the box in the lower left of the dialog form if you want to save your choices for use
       in all new future projects as well.
    4.  Click OK to accept your choice of defaults.
The specific items for each category of defaults will be discussed next.

Default ID Labels
The  ID Labels page  of the Project Defaults dialog  form is used to  determine  how SWMM will
assign  default  ID labels for the visual project components when they are first created. For each
type of object you can enter a label  prefix in the corresponding entry field or leave the field blank
if an object's default name will simply be a number. In the last field you can enter an increment to
be used when  adding a numerical suffix to the default label. As an example,  if C were used as a
prefix for Conduits along with an increment of 5, then as conduits are created they receive default
names of C5,  C10, C15, and so on. An object's default name can be changed by  using the
Property  Editor for visual objects or the object-specific editor for non-visual objects.

Default Subcatchment Properties
The  Subcatchment page  of  the Project  Defaults dialog sets  default property values  for newly
created subcatchments. These properties include:
    •  Subcatchment Area
    •  Characteristic Width
    •  Slope
    •  % Impervious
    •  Impervious Area Roughness
    •  Pervious Area Roughness
    •  Impervious Area Depression Storage
    •  Pervious Area Depression Storage
    •  % of Impervious Area with No Depression Storage
    •  Infiltration Method
The default properties of a Subcatchment can be modified later by using the Property Editor.

Default Node/Link Properties
The  Nodes/Links page of the Project Defaults dialog  sets default  property  values  for newly
created nodes  and links. These properties include:
    •  Node Invert Elevation
    •  Node Maximum Depth
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    •   Node Ponded Area
    •   Conduit Length
    •   Conduit Shape and Size
    •   Conduit Roughness
    •   Flow Units
    •   Link Offsets Convention
    •   Routing Method
    •   Force Main Equation

The defaults automatically assigned to individual objects can be changed by using the object's
Property  Editor. The choice of Flow Units and Link Offsets Convention can be changed directly
on the main window's Status Bar.


5.5    Measurement Units

SWMM can use either US units or SI metric units. The choice of flow units determines what unit
system is used for all other quantities:
    •   selecting  CFS (cubic feet  per second),  GPM (gallons per minutes),  or  MGD (million
       gallons per day) for flow units implies that US units will be used throughout
    •   selecting CMS (cubic  meters per second), LPS (liters per second), or MLD (million liters
       per day) as flow units implies that SI units will be used throughout.

Flow units can be selected directly on the main window's Status  Bar or by setting a project's
default values. In  the latter  case the selection can  be saved so that all new future projects will
automatically use those units.

  F":
       The units  of previously entered data are  not automatically adjusted if the unit system is
       changed.
5.6    Link Offset Conventions

Conduits and flow regulators (orifices, weirs, and outlets) can be offset some distance above the
invert of their connecting end nodes as depicted below:
                                           97

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There are two different conventions  available for specifying the  location  of these offsets. The
Depth convention uses the offset distance from the node's invert (distance between © and  ©, in
the figure above). The Elevation convention uses the absolute elevation of the offset location (the
elevation of point © in the figure). The choice of convention can  be made on the Status Bar of
SWMM's main window or on the Node/Link Properties page of the Project Defaults dialog. When
this convention is changed, a dialog will appear giving one the option to automatically re-calculate
all existing link offsets in the current project using the newly selected convention

5.7    Calibration Data
SWMM can compare the results of a simulation with measured field data in its Time Series Plots,
which are discussed in section 9.4. Before SWMM can use such calibration data they must be
entered into a specially formatted text file and registered with the project.

Calibration Files
Calibration  Files contain measurements of a  single parameter at one or more locations that can
be compared with simulated values in Time Series Plots. Separate files can be used for each of
the following parameters:
    •   Subcatchment Runoff
    •   Subcatchment Pollutant Washoff
    •   Groundwater Flow
    •   Groundwater Elevation
    •   Snow Pack Depth
    •   Node Depth
    •   Node Lateral Inflow
    •   Node Flooding
    •   Node Water Quality
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    •   Link Flow Rate
    •   Link Flow Depth
    •   Link Flow Velocity
The format of the file is described in Section 11.5.
Registering Calibration Data
To register calibration data residing in a Calibration File:
    l.  Select Project » Calibration Data from the Main Menu.
    2.  In the Calibration Data dialog form shown below, click in the box next to the parameter
        (e.g., node depth, link flow, etc.) whose calibration data will be registered.
    3.  Either type in the name of a Calibration File for this parameter or click the Browse button
        to search for it.
    4.  Click the Edit button if you want to  open the Calibration File  in Windows NotePad for
        editing.
    5.  Repeat steps 2 - 4 for any other parameters that have calibration data.
    6.  Click OK to accept your selections.
 Calibration Data
     Calibration Variable
     Subcatchment Runoff
     Subcatchment Wash off
     Node Water Depth
     Link Flow Rate
     Node Water Quality
     Node Lateral Inflow
     Node Flooding
     Groundwater Flow
     Groundwater Elevation
     Snow Pack Depth
     Link Flow Depth
     Link Flow Velocity
Name of Calibration File
                                                                         Cancel
                                                      Help
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5.8    Viewing All Project Data

A  listing  of all project data (with the exception of map  coordinates)  can be viewed  in a non-
editable window, formatted  for input to SWMM's computational engine (see below). This can be
useful for checking data consistency and to make sure that no key components are missing. To
view such a listing select Project » Details from the Main Menu. The format of the data in this
listing is the same as that used when the file is saved to disk.  It is described in detail in Appendix
D.2.
& Project Data
Data Category
[TITLE]
[OPTIONS]
[EVAPORATION]
[RAINGAGES]

[SUBAREAS]
[INFILTRATION]
[JUNCTIONS]
[OUTFALLS]
[CONDUITS]
[XSECTIONS]

C3 1
Name Rain Gage Outlet
* 1 RG1 9
2 RG1 10
3 RG1 13
E 4 RG1 22
i 5 RG1 15
6 RG1 23
7 RG1 19
8 RG1 18


__J

B Juan!
Area
10
10
5
5
15
12
4
10


t
                                           100

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                 CHAPTER 6 - WORKING WITH OBJECTS
SWMM uses various types of objects to model a drainage area and its conveyance system. This
section describes how these objects can be created, selected, edited, deleted, and repositioned.


6.1     Types of Objects

SWMM contains both physical objects that can appear on its Study Area Map, and non-physical
objects that encompass design, loading, and  operational information. These objects, which are
listed in the Project Browser and were described in Chapter 3, consist of the following:

                  Project Title/Notes             Nodes
                  Simulation Options            Links
                  Climatology                  Transects
                  Rain Gages                  Control Rules
                  Subcatchments               Pollutants
                  Aquifers                      Land Uses
                  Snow Packs                  Curves
                  Unit Hydrographs              Time Series
                  LID Controls                  Time Patterns
                                              Map Labels


6.2     Adding Objects

To add a new object to a project, select the type of object from the upper pane of the Project
Browser and either  select Project » Add a New ... from the Main Menu or click the Browser's
 * button. If the object has a button on the Object Toolbar you can  simply click the toolbar button
instead.

If the object is a visual object that appears on the Study Area Map  (a Rain Gage, Subcatchment,
Node, Link, or Map Label) it will automatically receive a default ID name and a prompt will appear
in the Status Bar telling you how to proceed. The steps used to draw each of these objects on the
map are detailed below:

Rain Gages
Move the mouse to the desired location on the Map and left-click.

Subcatchments
Use the mouse to draw a polygon outline of the subcatchment on the Map:

•   left-click at each vertex
•   right-click or press  to close the polygon
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•   press the  key if you wish to cancel the action.
Nodes (Junctions, Outfalls, Flow Dividers, and Storage Units')
Move the mouse to the desired location on the Study Area Map and left-click.
 Links (Conduits, Pumps, Orifices, Weirs, and Outlets')
•   Left-click the mouse on the link's inlet (upstream) node.
•   Move  the  mouse  (without  pressing  any  button)   in the  direction  of the link's outlet
    (downstream)  node,  clicking  at  all  intermediate points  necessary  to  define  the  link's
    alignment.
•   Left-click the mouse  a final time over the link's outlet (downstream) node. (Pressing the right
    mouse button  or the  key while drawing a link will cancel the operation.)
Map Labels
•   Left-click the mouse on the map location where the top left corner of the label should appear.
•   Enter the text for the  label.
•   Press   to accept the label or  to cancel.
 For all other non-visual types of objects, an object-specific dialog form will appear that allows you
to name the  object and edit its properties.

6.3     Selecting and Moving Objects
To select an object on the map:
    l. Make sure that the map is in Selection  mode (the mouse cursor has the shape of an
       arrow pointing up to the  left). To switch to this mode, either click the Select Object button
        * on the Map Toolbar or choose Edit » Select Object from the Main Menu.
    2. Click the mouse over the desired object on the map.
To select an object using the Project Browser:
    l. Select the object's category from the upper list in the Browser.
    2. Select the object from the lower list in the Browser.
Rain gages, subcatchments, nodes, and map labels can be moved  to another  location on the
Study Area Map. To move an object to another location:
    l. Select the object on the map.
    2. With the left mouse button held down over the object, drag it to its new location.
    3. Release the mouse button.
The following alternative method can also be used:
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    l.  Select the object to be moved from the Project Browser (it must either be a rain gage,
       subcatchment, node, or map label).
    2.  With the left mouse button held down, drag the item from the Items list box of the Data
       Browser to its  new location on the map.
    3.  Release the mouse button.

Note that the second method can be used to place objects on the map that were imported from a
project file that had no coordinate information included in it.


6.4    Editing Objects

To edit an object appearing on  the Study Area  Map:
    l.  Select the object on the map.
    2.  If the Property Editor is not visible either:
       •   double click on the object
       •   or right-click on the object and select Properties from the pop-up menu that appears
       •   or click on &  in the Project Browser
       •   or select Edit » Edit Object from the Main Menu.
    3.  Edit the object's properties  in the Property Editor.

Appendix B lists the properties  associated with each of SWMM's visual objects.

To edit an object listed in the Project Browser:
    l.  Select the object in the Project Browser.
    2.  Either:

       •   click on & in the Project Browser,
       •   or select Edit » Edit Object from the Main Menu,
       •   or double-click the  item in the Objects list,
       •   or press the  key.

Depending on the class of object selected,  a special property editor will  appear in which  the
object's properties can be  modified. Appendix C describes all of the special property editors used
with SWMM's non-visual objects.

  r,
       The unit system in which object properties are expressed depends on the  choice of units
       for flow rate. Using a flow  rate expressed in cubic feet,  gallons or acre-feet implies that
       US units  will be used  for  all quantities.  Using a flow rate expressed  in  liters or cubic
       meters means that SI  metric units will be used.  Flow units are selected either from the
       project's default Node/Link properties (see Sections.4) or directly from the  main window's
       Status Bar (see Section 4.4). The units used for all properties are listed in Appendix A.1.
                                           103

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6.5    Converting an Object

It is possible to convert a node or link from one type to another without having to first delete the
object and add a new one in its place. An example would be converting a Junction node into an
Outfall node, or converting an Orifice link into a Weir link. To convert a node or link to another
type:
    l. Right-click the object on the map.
    2. Select Convert To from the popup menu that appears.
    3. Select the new type of node or link to convert to from the sub-menu that appears.
    4. Edit the object to provide any data that was not included with the previous type of object.

Only data that  is common to both types of objects will be preserved after an object is converted to
a different type.  For nodes this includes its  name, position, description, tag, external inflows,
treatment functions,  and  invert  elevation.  For links  it  includes just  its  name, end  nodes,
description, and tag.


6.6    Copying and Pasting Objects

The  properties of an object displayed  on the Study  Area Map can  be copied and pasted into
another object from the same category.

To copy the properties of an object to SWMM's internal clipboard:
    l. Right-click the object on the map.
    2. Select Copy from the pop-up menu that appears.

To paste  copied properties into an object:
    l. Right-click the object on the map.
    2. Select Paste from the pop-up menu that appears.

Only data that can  be  shared between  objects of the same type can be  copied and pasted.
Properties not  copied include the object's name, coordinates, end  nodes  (for links), tag property
and any descriptive comment associated with  the object. For Map Labels,  only font properties are
copied and pasted.


6.7    Shaping  and Reversing Links

Links can be drawn  as polylines containing any number of straight-line segments that define the
alignment or curvature of the link. Once  a link  has been  drawn on the map, interior points that
define these line segments can be added, deleted, and moved. To edit the interior points of a link:
    l. Select the link to edit on the map and  put the map  in Vertex Selection mode either by
       clicking  P- on the Map Toolbar, selecting Edit » Select Vertex from the Main Menu, or
       right clicking on the link and selecting Vertices from the popup menu.
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    2.  The mouse pointer will change shape to an arrow tip, and any existing vertex points on
       the link will be displayed as small open squares. The currently selected vertex will be
       displayed as a filled square. To select a particular vertex, click the mouse over it.
    3.  To add a new vertex to the link, right-click the mouse and select Add Vertex from the
       popup menu (or simply press the  key on the keyboard).
    4.  To delete the currently selected vertex, right-click the mouse and select Delete Vertex
       from the popup menu (or simply press the  key on the keyboard).
    5.  To move a vertex to another location, drag it to its  new position with the left mouse button
       held down.
While in  Vertex Selection mode you can begin editing the  vertices for another link by  simply
clicking on the link. To leave  Vertex Selection mode, right-click on the map and select Quit
Editing from the popup menu, or simply select one of the other buttons on the Map Toolbar.

A link can also have its direction reversed  (i.e., its end nodes switched) by right clicking on it and
selecting  Reverse from the pop-up menu that appears. Normally, links should be oriented so that
the upstream end is at a higher elevation than the downstream end.


6.8    Shaping a Subcatchment

Subcatchments are drawn on the Study Area Map as closed  polygons. To edit  or add vertices to
the polygon, follow the same procedures used for links.  If the subcatchment is originally drawn or
is edited to have two or less vertices, then only its centroid symbol will be displayed on the Study
Area Map.


6.9    Deleting an Object

To delete an object:
    l.  Select the object on the map or from the Project Browser.

    2.  Either click the  ~  button  on the Project Browser  or press the  key on the
       keyboard, or select Edit » Delete Object from the  Main Menu, or right-click the object
       on the map and select Delete from the pop-up menu that appears.
       You can require that all deletions be confirmed before they take effect. See the General
       Preferences page of the Program Preferences dialog box described in Section 4.9.
6.10   Editing or Deleting a Group of Objects

A group of objects located within an irregular region of the Study Area Map can have a common
property edited or be deleted all together. To select such a group of objects:

    l.  Choose Edit » Select Region from the Main Menu or click ££•  on the Map Toolbar.
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    2.   Draw a polygon around the region of interest on the map by clicking the left mouse button
        at each successive vertex of the polygon.
    3.   Close the polygon by clicking the right button or by pressing the  key; cancel the
        selection by pressing the  key.
To select all objects in the project, whether in view or not, select Edit » Select All from the Main
Menu.
Once a group of objects  has been selected,  you can edit a common property shared among
them:
    l.  Select Edit » Group Edit from the Main Menu.
    2.  Use the Group Editor dialog that appears to select a property and specify its new value.

The Group  Editor dialog,  shown below, is used to  modify a  property for a selected group of
objects. To use the dialog:
     Group Editor


       For objects of type


       F] with Tag equal to


       edit the property
Subcatchment
        by replacing it with   T     75
              OK
    l.  Select  a type  of object  (Subcatchments,  Infiltration,  Junctions,  Storage  Units,  or
        Conduits) to edit.
    2.  Check the "with Tag equal to" box if you want to add a filter that will limit the objects
        selected for editing to those with a specific Tag value. (For Infiltration, the Tag will be that
        of the subcatchment to which the infiltration parameters belong.)
    3.  Enter a Tag value  to filter on if you have selected that option.
    4.  Select the property to edit.
    5.  Select whether to  replace,  multiply, or add to the existing  value of the property. Note that
        for some non-numerical properties the only available  choice is to replace the value.
    6.  In the lower-right edit box, enter the value that should replace, multiply, or be added to
        the existing value for all selected objects. Some properties will have  an  ellipsis button
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       displayed in the edit box which should be clicked to bring up a specialized editor for the
       property.
    7.  Click OK to execute the group edit.

After the  group edit is executed a confirmation dialog box will appear informing you of how many
items were modified. It will ask if you wish to  continue editing or not. Select Yes to return to the
Group Edit dialog  box to edit another parameter or No to dismiss the Group Edit dialog.

To delete the objects located within a selected area of the map, select Edit  » Group Delete
from the  Main Menu. Then select the categories of objects you wish to delete from the dialog box
that appears. As an option, you can specify that only objects within the selected area that have a
specific Tag property should be deleted. Keep in  mind that deleting a node will also delete any
links connected to the node.
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                  CHAPTER 7 -WORKING WITH THE MAP
EPA SWMM can display a map of the study area being modeled. This section describes how you
can manipulate this map to enhance your visualization of the system.


7.1     Selecting a Map Theme

A map theme displays object properties in color-coded fashion on the Study Area Map. The
dropdown  list boxes on  the  Map  Browser are  used  for selecting a theme to display for
Subcatchments, Nodes and Links.
 & SWMM 5.1 - Examplel.inp
  File   Edit  View   Project  Report  Tools  Window
                    Hdp
    D
  Project]  Map
    Themes
    Subcatchments
    Runoff
    Nodes
    Depth
    Links
    Flow
    Time Period
    Date

                            Study Area Map
Subcatch
Runoff

0.01
0.05
0.10
0.50
CFS
                            Node
                            Depth
                            0.40
Methods for changing the color-coding associated with a theme are discussed in Section 7.10
below.
7.2    Setting the Map's Dimensions

The physical dimensions of the map can be defined so that map coordinates can  be properly
scaled to the computer's video display. To set the map's dimensions:
    l.  Select View » Dimensions from the Main Menu.
    2.  Enter coordinates for the lower-left and upper-right corners of the map into the Map
       Dimensions dialog (see below) that appears or click the Auto-Size button to automatically
       set the dimensions based on the coordinates of the objects currently included in the map.
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         Map Dimensions

           Lower Left

            X-coordinate:  0,000

            Y-coordinate:  0,000
             Upper Right

              X-coordinate:  10000,000

              Y-coordinate:  10000,000
           Map Units

           • < Feet
Meters
Degrees
*:Q, None
             J Auto-Length is ON. Re-compute all lengths and areas?
                                  OK
    3.  Select the distance units to use for these coordinates.
    4.  If the Auto-Length option is in effect, check the "Re-compute all lengths and areas" box
       if you would like SWMM to re-calculate all conduit lengths and subcatchment areas under
       the new set of map dimensions.
    5.  Click the OK button to resize the map.
       If  you are going  to  use a  backdrop image with  the automatic distance  and  area
       calculation feature, then it is recommended that you set the map dimensions immediately
       after creating a new project. Map distance units can be different from conduit length units.
       The latter (feet or meters) depend on whether flow rates are expressed in US or metric
       units. SWMM will automatically convert units if necessary.

       If you just want to re-compute conduit lengths and  subcatchment areas without changing
       the map's dimensions, then just check the Re-compute Lengths and Areas box and leave
       the coordinate boxes as they are.
7.3    Utilizing a Backdrop Image

SWMM can display a backdrop image behind the Study Area Map. The backdrop image might be
a street map, utility map, topographic map, site development plan, or any other relevant picture or
drawing. For example, using a street map would simplify the process of adding sewer lines to the
project since one could essentially digitize the  drainage system's nodes and links directly on top
of it.
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     Study Area Map
The backdrop image must be a Windows metafile, bitmap, or JPEG image created outside of
SWMM. Once imported, its features cannot be edited, although  its scale and  viewing area will
change as the map window is zoomed and  panned. For this reason metafiles work better than
bitmaps or JPEGs since they will  not lose resolution  when re-scaled. Most  CAD and CIS
programs have the ability to save their drawings and maps as metafiles.

Selecting View » Backdrop from the Main Menu will  display  a sub-menu with the following
commands:
    •   Load (loads a backdrop image file into the project)
    •   Unload (unloads the backdrop image from the project)
    •   Align (aligns the drainage system schematic with  the backdrop)
    •   Resize (resizes the map dimensions of the backdrop)
    •   Watermark (toggles the backdrop image appearance between normal and lightened)

To load a backdrop image select View » Backdrop » Load from the Main Menu. A Backdrop
Image Selector dialog form will be displayed. The entries on this form are as follows:
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  Backdrop Image Selector

   Backdrop Image File
    sample.wmf

   World Coordinates File (optional)
    sample.bpw


   [  | Scale Map to Backdrop Image
        OK
Backdrop Image File

Enter the name of the file that contains the image. You can click the UU button to bring up a
standard Windows file selection dialog from which you can search for the image file.

World Coordinates File
                                                               ion
If a "world" file exists for the image, enter its name here, or click the     button to search for it. A
world file contains  geo-referencing  information for the  image  and can  be created from  the
software that  produced the  image file or by using a text editor. It  contains six lines with  the
following information:
Line 1:  real world width of a pixel in the horizontal direction.
Line 2:  X rotation parameter (not used).
Line 3:  Y rotation parameter (not used).
Line 4:  negative of the real world height of a pixel in the vertical direction.
Line 5:  real world X coordinate of the upper left corner of the image.
Line 6:  real world Y coordinate of the upper left corner of the image.
If no world file is specified,  then the backdrop will be scaled to fit  into the center of the map
display window.

Scale Map to Backdrop Image

This option  is only  available when a  world file  has been  specified.  Selecting  it forces  the
dimensions of the Study Area Map to coincide with those of the backdrop  image. In addition, all
existing objects on the map will  have their coordinates adjusted so that they appear within  the
new map dimensions yet maintain their relative positions to one another. Selecting this option
may then require that the backdrop be re-aligned so that its position relative to the drainage area
objects  is correct. How to do this  is described below.
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The backdrop image can be re-positioned relative to the drainage system by selecting View »
Backdrop » Align. This allows the backdrop image to be moved across the drainage system
(by moving the mouse with the left button held down) until one decides that it lines up properly.

The backdrop image can also be resized by selecting View » Backdrop » Resize. In this case
the following Backdrop Dimensions dialog will appear.
  Backdrop Dimensions

     Lower Left
                   Backdrop
      X-coordinate:    -23,360

      Y-coordinate:    -29.165


     Upper Right
                   Backdrop
      X-coordinate:    1463.996

      Y-coordinate:    1512.277


   •p1 Resize Backdrop Image Only

   •  • Scale Backdrop Image to Map

   •  • Scale Map to Backdrop Image
Map
-39,947
Map
•I -ion cor-
X^uU ,.,Ju,j
                        Cancel
The dialog lets you manually enter the X,Y coordinates  of the backdrop's lower left and upper
right corners.  The Study Area  Map's dimensions are also displayed  for reference. While the
dialog is visible you can view map coordinates by moving the  mouse over the map window and
noting the X,Y values displayed in SWMM's Status Panel (at the bottom of the main window).
Selecting the Resize Backdrop Image Only button will resize only the backdrop, and  not the
Study Area Map, according to the coordinates specified. Selecting the Scale Backdrop Image to
Map button will position the backdrop image  in the  center of the Study Area Map  and  have it
resized to fill the display window without changing its aspect ratio. The map's lower left and upper
right coordinates will be placed  in the data entry fields for the backdrop coordinates, and these
fields will become disabled. Selecting Scale Map to Backdrop Image makes the dimensions of
the map coincide with the dimensions being set for the backdrop image. Note that this option will
change  the coordinates of all objects currently on the map so  that their positions relative to one
another remain unchanged. Selecting this option may then  require that the backdrop be re-
aligned so that its position relative to the drainage area objects  is correct.
                                           112

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  *";
       Exercise caution when selecting the Scale Map to Backdrop Image option in either the
       Backdrop Image Selector dialog or the Backdrop Dimensions dialog as it will modify the
       coordinates of all existing objects currently on the Study Area Map. You might want to
       save your project before carrying out this step in case the results are not what you
       expected.

The name of the backdrop image file and its map dimensions are saved  along with the rest of a
project's data whenever the project is saved to file.

For best results in using a backdrop image:
   •   Use a metafile, not a bitmap.
   •   If the image is loaded before any objects are added to the project then scale the map to
       it.
7.4    Measuring Distances

To measure a distance or area on the Study Area Map:

             n
    l.  Click i==i on the Map Toolbar.

    2.  Left-click on the map where you wish to begin  measuring from.

    3.  Move the mouse over the distance being measured, left-clicking  at each intermediate
       location where the measured path changes direction.

    4.  Right-click the mouse or press  to complete the measurement.

    5.  The distance  measured in project units (feet or meters) will be displayed in a dialog box.
       If the  last point on the measured path  coincides with the first point then the  area of the
       enclosed polygon will also be displayed.


7.5    Zooming the  Map

To Zoom In on the Study Area Map:

    l.  Select View » Zoom In from the Main Menu or click ^ on the Map Toolbar.
    2.  To zoom in 100% (i.e., 2X), move the mouse to the center of the zoom area and click the
       left button.
    3.  To  perform a custom zoom, move the  mouse to the upper left corner of the zoom area
       and with the left button pressed down, draw a rectangular outline around the  zoom area.
       Then release  the left button.
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To Zoom Out on the Study Area Map:
    l.  Select View » Zoom Out from the Main Menu or click ^ on the Map Toolbar.
    2.  The map will be returned to the view in effect at the previous zoom level.

7.6     Panning the Map
To pan across the Study Area Map window:
    l.  Select View » Pan from the Main Menu or click  *f* on the Map Toolbar.
    2.  With the left button held down over any point on the map, drag the mouse in the direction
       you wish to pan in.
    3.  Release the mouse button to complete the pan.
To pan using the Overview Map (which is described in Section 7.11 below):
    l.  If not already visible, bring up the Overview Map by selecting View » Overview Map
       from the Main Menu or click the ® button on the  Standard Toolbar.
    2.  If the Study Area Map has been zoomed in, an  outline of the  current  viewing area will
       appear on the Overview Map. Position the mouse  within  this  outline  on the Overview
       Map.
    3.  With the left button held down, drag the outline to  a new position.
    4.  Release the  mouse button  and the  Study  Area  Map will  be panned to  an area
       corresponding to the outline on the Overview Map.

7.7     Viewing at Full Extent
To view the Study Area Map  at full extent, either:
    •   select View » Full Extent from the Main Menu, or
    •   press H on the Map Toolbar.

7.8     Finding an Object
To find an object on the Study Area Map whose name is known:
    l.  Select View » Find Object from the Main Menu  or click 04 on the Standard Toolbar.
    2.  In the Map Finder dialog that appears, select the type of object to find and enter its name.
    3.  Click the Go button.
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 Map Finder
  Find
  Named
  i  Go
           Node
14

Adjacent Links

11
If the object exists, it will  be highlighted on the map and in the Data Browser. If the  map is
currently zoomed in and the object falls outside the current map boundaries, the map will be
panned so that the object comes into view.
       User-assigned  object names  in SWMM are not case  sensitive.  E.g.,  NODE123 is
       equivalent to Node123.
After an object is found, the Map Finder dialog will also list:
    •   the outlet connections for a subcatchment
    •   the connecting links for a node
    •   the connecting nodes for a link.


7.9    Submitting a Map Query

A Map Query identifies objects on the study area map that meet a specific criterion (e.g., nodes
which flood, links with velocity below 2 ft/sec, etc.). It can also identify which subcatchments have
LID controls and which nodes have external inflows. To submit a map query:
    l. Select a time period in which to query the map from the Map Browser.

    2. Select View » Query or click ?li on the Standard Toolbar.
    3. Fill in the following information in the Query dialog that appears:
       •   Select whether to search  for Subcatchments, Nodes,  Links, LID Subcatchments or
           Inflow Nodes.
       •   Select a parameter to query or the type of LID or inflow to locate.
       •   Select the appropriate operator: Above, Below, or Equals.
       •   Enter a value to compare against.
    4. Click the Go button. The number of objects that meet the criterion will be displayed in the
       Query dialog and each such object will be highlighted on the Study Area Map.
    5. As a new time period  is selected  in the Browser, the query results are automatically
       updated.
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    6.  You can submit another query using the dialog box or close it by clicking the button in the
       upper right corner.
         Study Area Map

After the Query box is closed the map will revert back to its original display.
7.10   Using the Map Legends
     Flow

     4.00
     8.00
     12.00
     16.00
     CFS
Map Legends associate a  color with  a range of values  for the current
theme  being  viewed. Separate legends exist for  Subcatchments, Nodes,
and Links. A Date/Time Legend  is also available for displaying  the date
and clock time of the simulation period being viewed on the map.
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To display or hide a map legend:
    l. Select View  » Legends from the Main Menu or right-click on the map and select
       Legends from the pop-up menu that appears
    2. Click on the type of legend whose display should be toggled on or off.
A visible legend can also be hidden by double clicking on it.

To  move a legend to another  location press the  left mouse button over the legend, drag the
legend to its new location with the button held down, and then release the button.

To edit a legend, either select View » Legends » Modify from the Main Menu or right-click on
the legend if it is visible. Then use the Legend Editor dialog that appears to modify the legend's
colors and intervals.
The  Legend Editor is  used to set numerical  ranges to which different colors  are assigned for
viewing a particular parameter on the network map. It works as follows:
    •  Numerical values, in increasing order, are entered in the edit boxes to define the ranges.
       Not all four boxes need to have values.
    •  To change a color, click on  its color band in the Editor and then select  a new color from
       the Color Dialog that will appear.
    •  Click the Auto-Scale button to automatically assign ranges based on the minimum and
       maximum values attained by the parameter in question at the current time period.
    •  The Color Ramp button is used to select from a list of built-in color schemes.
    •  The Reverse Colors button reverses the ordering of the current set of colors (the color in
       the lowest range becomes that of the highest range and so on).
    •  Check Framed if you want a frame drawn around  the legend.
Changes made  to a legend are saved  with the  project's  settings and remain in effect when the
project is re-opened in  a subsequent session.
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7.11    Using the Overview Map

The Overview Map, as pictured below, allows one to see where in terms of the overall system the
main Study Area Map is currently focused. This zoom area is depicted by the rectangular outline
displayed on the Overview Map. As you drag this rectangle to another position the view within the
main map will be redrawn accordingly. The Overview Map can be toggled on and off by selecting
View »  Overview Map from the  Main Menu or by clicking ® on the Standard Toolbar. The
Overview Map window can also be dragged to any position as well as be re-sized.
   . Study Area Map
        Overview Map
E)
                  EL
7.12   Setting Map Display Options

The Map Options dialog (shown below) is used to change the appearance of the Study Area Map.
There are several ways to invoke it:
    •   select Tools » Map Display Options from the Main Menu or,
       click the Options button  HIT on the Standard Toolbar when the Study Area Map window
       has the focus or,
       right-click on any empty portion of the map and select Options from the popup menu that
       appears.
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 Map Options


   Nodes
   Links
   Labels
   Annotation
   Symbols
   Flow Arrows
   Background
 Fill Style
  ;  Clear
    Solid
 o- Diagonal
    Cross Hatch

Symbol Size       5

Border Size        1

Mj Display link to outlet
           OK
The dialog contains a separate page, selected from the panel on the left side of the form, for each
of the following display option categories:
    •   Subcatchments  (controls fill  style, symbol size,  and outline thickness  of subcatchment
       areas)
    •   Nodes (controls  size of nodes and making size be proportional to value)
    •   Links (controls thickness of links and making thickness be proportional to value)
    •   Labels (turns display of map labels on/off)
    •   Annotation (displays or hides node/link ID labels and parameter values)
    •   Symbols (turns display of storage unit, pump, and regulator symbols on/off)
    •   Flow Arrows (selects visibility and style of flow direction arrows)
    •   Background (changes color of map's background).

Subcatchment Options
The  Subcatchments page  of the  Map Options dialog  controls  how subcatchment areas are
displayed on the study area map.
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    Option              Description
    Fill Style            Selects style used to fill interior of subcatchment area
    Symbol Size        Sets the size of the symbol (in pixels) placed at the centroid of a
                       subcatchment area
    Border Size         Sets the thickness of the line used to draw a subcatchment's
                       border; if set to zero then only the subcatchment centroid will be
                       displayed
    Display Link to      If checked then a dashed line is drawn between the subcatchment
    Outlet              centroid and the subcatchment's outlet node (or outlet
                       subcatchment)
Node Options

The Nodes page of the Map Options dialog controls how nodes are displayed on the study area
map.

    Option             Description
    Node Size          Selects node diameter in pixels
    Proportional to      Select if node size should increase as the viewed parameter
    Value               increases in value
    Display Border      Select if a border should be drawn around each node
                       (recommended for light-colored backgrounds)


Link Options

The Links  page of the Map Options dialog controls how links are displayed on the map.

    Option              Description
    Link Size            Sets thickness of links displayed on map (in pixels)
    Proportional to       Select if link thickness should increase as the viewed parameter
    Value                increases in value
    Display Border       Check if a black border should be drawn around each link


Label Options

The Labels page of the Map Options dialog controls how user-created  map labels are displayed
on the study area map.
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    Option
Description
    Use Transparent
    Text
    At Zoom Of
Check to display label with a transparent background (otherwise
an opaque background is used)
Selects minimum zoom at which labels should be displayed;
labels will be hidden at zooms smaller than this
Annotation Options
The Annotation page of the  Map  Options dialog  form  determines what kind of annotation is
provided alongside of the objects on the study area  map.
    Option
    Description
    Rain Gage IDs
    Subcatch IDs
    Node IDs
    Link IDs
    Subcatch Values
    Node Values
    Link Values
    Use Transparent Text

    Font Size
    At Zoom Of
    Check to display rain gage ID names
    Check to display subcatchment ID names
    Check to display node ID names
    Check to display link ID names
    Check to display value of current subcatchment variable
    Check to display value of current node variable
    Check to display value of current link variable
    Check to display text with a transparent background
    (otherwise an opaque background is used)
    Adjusts the size of the font used to display annotation
    Selects minimum zoom at which annotation should be
    displayed; all annotation will be hidden at zooms smaller
    than this
Symbol Options
The Symbols page of the Map Options dialog determines which types of objects are represented
with special symbols on the map.
    Option
   Description
    Display Node Symbols
    Display Link Symbols
    At Zoom Of
   If checked then special node symbols will be used
   If checked then special link symbols will be used
   Selects minimum zoom at which symbols should be
   displayed; symbols will be hidden at zooms smaller than this
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Flow Arrow Options
The  Flow Arrows  page of the Map Options dialog  controls how flow-direction arrows are
displayed on the map.
    Option             Description
    Arrow Style         Selects style (shape) of arrow to display (select None to hide
                       arrows)
    Arrow Size          Sets arrow size
    At Zoom Of         Selects minimum zoom at which arrows should be displayed;
                       arrows will be hidden at zooms smaller than this
       Flow direction arrows will only be displayed after a successful simulation has been made
       and a computed parameter has been selected for viewing. Otherwise the direction arrow
       will point from the user-designated start node to end node.
Background Options
The Background page of the Map Options dialog  offers a selection of colors used to paint the
map's background with.

7.1 3    Exporting the Map
The full extent view of the study area map can be saved to file using either:
   •   Autodesk's DXF (Drawing Exchange Format) format,
   •   the Windows enhanced metafile (EMF) format,
   •   EPA SWMM's own ASCII text (.map) format.
The DXF format is readable  by many Computer Aided Design (CAD) programs. Metafiles can be
inserted into word processing documents and loaded into drawing programs for re-scaling and
editing. Both formats are vector-based and will  not lose resolution when they are displayed at
different scales.
To export the map to a DXF, metafile, or text file:
   l .  Select File » Export » Map.
   2 .  In the Map Export dialog that appears select the format that you want the map saved in.
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     Map Export

        Export Map To;

         -6' Ted: File (.map)

            Enhanced Metafile (.emf)

            Drawing Exchange File (,dxf)
  OK
Cancel
 Help
If you select DXF format, you  have a choice  of how nodes will be represented in the DXF file.
They can be drawn as filled circles, as open circles, or as filled squares. Not all DXF readers can
recognize the format used in the DXF file to draw a filled circle. Also note that map annotation,
such as node and link ID labels will not be exported, but map label objects will be.

After choosing a format, click OK and enter a name for the file in the Save As dialog that appears.
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                  CHAPTER 8 - RUNNING A SIMULATION
After a study area has been suitably described, its runoff response, flow routing and water quality
behavior can be simulated. This section describes  how to specify options to be used in the
analysis, how to run the simulation and how to troubleshoot common problems that might occur.


8.1     Setting Simulation Options

SWMM has a number of options that control how the  simulation of a stormwater drainage system
is carried out. To set these options:
    l.  Select the Options category from the Project Browser.
    2.  Select one of the following categories of options to edit:
           a.  General Options
           b.  Date Options
           c.  Time  Step Options
           d.  Dynamic Wave Routing Options
           e.  Interface File Options
           f.  Reporting  Options

    3.  Click the &  button on the Browser panel or select Edit » Edit Object to  invoke the
       appropriate editor  for the chosen option category (the Simulation Options dialog is  used
       for the first five categories while the Reporting Options dialog is used for the last one).

The Simulations Options dialog contains a separate tabbed page for each of the first five option
categories listed above. Each page is described in more detail below.


8.1.1   General Options

The General page of the Simulation Options dialog sets values for the following options:

Process Models
This section allows you to  select which of SWMM's process models will be applied to the current
project. For example, a model that  contained Aquifer and Groundwater elements could be run
first with the groundwater computations turned on and then again with them  turned off to see
what effect this process had on the site's hydrology. Note that if there are no elements in the
project needed to model a given process then that process option is disabled (e.g., if there  were
no Aquifers defined for the project then the Groundwater check box will appear disabled  in an
unchecked state).
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Simulation Options
General j Dates Time Steps
Process Models
U/j Rainfall/Runoff
Rainfall Dependent I/I

Sncv'v Melt

Ground'A-ater

M] Flow Routing

Water Quality

Routing Model
• _ • Steady Flow

'O.1 Kinematic Wave

• • Dynamic Wave
p^irn


; Dynamic Wave Files !
mj_immj||[im^^
Infiltration Model
\ • Morton
•:'_ ' Modified Morton
•,'.'• Green-Arnpt

<€»- Modified Green-Ampt

Curve Number

Miscellaneous

CH Allow Ponding
i_] Report Control Actions

[ 	 | Report Input Summary

Minimum Conduit Slope
0 (%)
Cancel Help























Infiltration Model
This option controls  how infiltration of rainfall into the upper soil zone of subcatchments is
modeled. The choices are:
    •   Morton
    •   Modified Morton
    •   Green-Ampt
    •   Modified Green-Ampt
    •   Curve Number
Each of these  models is briefly described in section 3.4.2. Changing this option will require re-
entering  values for the  infiltration  parameters in  each subcatchment,  unless  the change is
between the two Morton options or the two Green-Ampt options.
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Routing Model
This option determines which method is used to route flows through the conveyance system. The
choices are:
    •   Steady Flow
    •   Kinematic Wave
    •   Dynamic Wave
Review section 3.4.5 for a brief description of each of these alternatives.
Allow Ponding
Checking this option will allow excess water to collect atop nodes and be re-introduced into the
system as conditions permit. In order for ponding to  actually occur at a particular node, a non-
zero value for its Ponded Area attribute must be used.
Report Control Actions
Check this option if you want the simulation's Status Report to  list all discrete control actions
taken by the Control Rules associated with a project (continuous modulated control actions are
not listed). This option should only be used for short-term simulation.
Report Input Summary
Check this option if you want the  simulation's Status Report to list a summary of the project's
input data.
Minimum  Conduit Slope
The minimum  value allowed for a conduit's  slope (%). If blank or zero (the default) then  no
minimum is imposed (although SWMM uses a lower  limit on elevation drop of 0.001 ft (0.00035
m) when computing a conduit slope).

8.1.2   Date Options
The Dates page of the Simulation Options dialog  determines the starting and ending dates/times
of a simulation.
Start Analysis On
Enter the date  (month/day/year) and time of day when the simulation begins.
Start Reporting On
Enter the date  and time of day when reporting of simulation results is to begin. Using a date prior
to the start date is the same as using the start date.
End Analysis  On
Enter the date  and time  when the simulation is to end.
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Start Sweeping On
Enter the day of the year (month/day) when street sweeping operations begin. The default is
January 1.

End Sweeping On
Enter the day of  the year (month/day) when street sweeping operations  end.  The default is
December 31.

Antecedent Dry Days
Enter the number  of days with no rainfall prior to the start of the simulation. This value is used to
compute an initial buildup of pollutant load on the surface of subcatchments.
       If rainfall or climate data are read from external files, then the simulation dates should be
       set to coincide with the dates recorded in these files.
8.1 .3   Time Step Options

The Time Steps  page of the Simulation Options dialog establishes the length of the time steps
used for runoff computation, routing computation and results reporting. Time steps are specified
in days and hours:minutes:seconds except for flow routing which is entered as decimal seconds.

Reporting Time  Step
Enter the time interval for reporting of computed results.

Runoff - Wet Weather Time Step
Enter the time step length used to compute runoff from subcatchments during periods of rainfall,
or when ponded  water still  remains on the surface, or when LID controls are still infiltrating or
evaporating runoff.

Runoff - Dry Weather Time Step
Enter the time  step length  used for  runoff computations (consisting  essentially of pollutant
buildup) during periods when there is no rainfall, no ponded water, and LID controls are dry. This
must be greater or equal to the Wet Weather time step.

Routing Time Step
Enter the time  step  length in decimal seconds used  for  routing  flows  and water  quality
constituents through the conveyance system. Note that Dynamic Wave routing requires a much
smaller time step than the  other methods of flow routing.

Steady Flow Periods
This set of options tells SWMM how to  identify and  treat periods of time when system  hydraulics
is not changing. The system is considered to be in a steady flow period if:
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    •   The percent difference between total system inflow and total system outflow is below the
       System Flow Tolerance,

    •   The percent differences between the current lateral inflow and that from the previous time
       step for all points in the conveyance system are below the Lateral Flow Tolerance.
Checking the Skip Steady Flow Periods box will make SWMM keep  using the most recently
computed  conveyance system flows (instead  of computing a new flow solution) whenever the
above criteria are met. Using this feature can help speed up simulation run times at the expense
of reduced accuracy.


8.1.4   Dynamic Wave Options

The Dynamic Wave page of the Simulation Options dialog sets several parameters that control
how the dynamic wave flow routing computations are made. These parameters have no effect for
the other flow routing methods.

Inertial Terms
Indicates how the inertial terms in the St. Venant momentum equation will be handled.
    •   KEEP maintains these terms at their full value under all conditions.
    •   DAMPEN  reduces the terms as flow comes  closer  to  being critical  and ignores them
       when flow is supercritical.
    •   IGNORE drops the terms  altogether from the momentum equation,  producing what is
       essentially a Diffusion Wave solution.

Define Supercritical Flow By
Selects the basis used to determine when supercritical  flow occurs in a conduit. The choices are:
    •   water surface slope only  (i.e., water surface slope > conduit slope)
    •   Froude number only (i.e., Froude number > 1.0)
    •   both water surface slope  and Froude number.
The first two choices were used in earlier versions of SWMM while the third choice, which checks
for either condition, is  now the recommended one.

Force Main Equation
Selects which equation will  be  used to compute  friction  losses during pressurized  flow for
conduits that have been assigned a Circular Force Main cross-section. The choices are either the
Hazen-Williams equation or the Darcy-Weisbach equation.

Use Variable Time Steps
Check the box if an internally computed variable time  step should be used at each routing time
period and select an adjustment (or safety) factor to apply to this time step. The variable time step
is computed so as to satisfy the Courant condition within each conduit. A  typical adjustment factor
would be 75% to provide some margin of conservatism. The computed variable time step will not
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be less than the minimum variable step discussed below nor be greater than the fixed time step
specified on the Time Steps page of the dialog.

Minimum Variable Time Step
This is the smallest time step allowed when variable time steps are used. The default value is 0.5
seconds. Smaller steps may be warranted, but they can lead to longer simulations runs without
much improvement in solution quality.

Time Step for Conduit Lengthening
This is a time step, in seconds, used to  artificially lengthen conduits so that they meet the Courant
stability criterion under full-flow conditions  (i.e., the travel time of a wave will not be smaller than
the specified conduit lengthening time step). As this value is decreased, fewer conduits will
require lengthening. A value of zero means that no conduits  will be lengthened. The ratio of the
artificial  length to the original length for each conduit is listed  in the Flow Classification table that
appears in the simulation's Summary Report (see Section 9.2).

Minimum Nodal Surface Area
This is a minimum surface area used at nodes when computing changes in water depth. If 0  is
entered, then the default value of 12.566 ft2 (1.167 m2) is used. This is the area of a 4-ft diameter
manhole. The value entered should be in square feet for US units or square meters for SI units.

Maximum Trials per Time Step
This is the maximum number of trials that SWMM uses at each time step to reach convergence
when updating hydraulic heads at the conveyance system's nodes. The default value is 8.

Head Convergence Tolerance
When the difference in computed head at each node  between successive trials  is below this
value the flow solution for the current time step is assumed  to  have  converged. The default
tolerance is 0.005 ft (0.0015 m).

Number of Threads
This selects the number of parallel computing threads to use on  machines equipped with multi-
core processors. The default is 1.

Clicking the Apply Defaults label will set all the Dynamic Wave options to their default values.


8.1.5   File Options

The  Files page of the Simulation Options dialog is used to specify which  interface files will be
used or saved during the simulation.  (Interface files are described in  Chapter 11.) The  page
contains a list box with  three buttons underneath it. The list box lists the currently selected files,
while the buttons are used as follows:
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Add    adds a new interface file specification to the list.
Edit    edits the properties of the currently selected interface file.
Delete  deletes the currently selected interface from the project (but not from your hard drive).
  General  Dates   Time Steps  Dynamic Wave  Files
  Specify interface files to use or save:
                 Add
Edit
Delete
When the Add or Edit buttons are clicked,  an Interface File Selector dialog appears where you
can specify the type of interface file, whether it should  be used  or saved,  and its  name.  The
entries on this dialog are as follows:
 Interface File Selector


    File Type;

    HOTSTART


    File Name;
    tesEL.hsf
 o  Save File
      Use File
              OK
            Help
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File Type
Select the type of interface file to be specified.

Use / Save Buttons
Select whether the named interface file will be used to supply input to a simulation run or whether
simulation results will be saved to it.

File Name
                                                            leal
Enter the name  of the interface file or click the Browse button U2J to select from a standard
Windows file selection dialog box.
8.2    Setting Reporting Options

The  Reporting Options dialog is used to select individual subcatchments, nodes, and  links that
will have detailed time series results saved for viewing  after a simulation has been  run. The
default for new projects is that all objects will have detailed results saved for them. The dialog is
invoked by selecting the Reporting category of Options from the Project Browser and clicking the
& button (or by selecting Edit » Edit Object from the main menu).

The  dialog  contains three tabbed pages - one each  for subcatchments, nodes, and links. It is a
stay-on-top form which means that you can select  items directly from the Study Area Map or
Project Browser while the dialog remains visible.
  Reporting Options

   Select objects for detailed reporting;
       Nodes
Links
                                  Add
         Subcatchments
                                 Remove
                                  Clear
                                  Close
        All Subcatchments
                                  Help
To include an object in the set that is reported on:
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    i.  Select the tab to which the object belongs (Subcatchments, Nodes or Links).
    2.  Unselect the "AM" check box if it is currently checked.
    3.  Select the specific object either from the Study Area Map  or from the listing in the
       Project Browser.
    4.  Click the Add button on the dialog.
    5.  Repeat the above steps for any additional objects.

To remove an item from the set selected for reporting:
    i.  Select the desired item in the dialog's list box.
    2.  Click the Remove button to remove the item.

To remove all items from the reporting set of a given object category, select the object category's
page and click the Clear button.

To include all objects of a given category in the reporting set, check the "AM" box on the page for
that  category (i.e., subcatchments, nodes, or links).  This  will override any individual items that
may be currently listed on the page.

To dismiss the dialog click the Close button.


8.3     Starting a Simulation

To start a simulation either select Project » Run Simulation from the Main Menu or click ^ on
the  Standard Toolbar.  A Run Status window will appear which displays the progress of the
simulation.
 Run Status

   *SI?V-,  Computing ...


   Percent Complete: 34%
   Simulated Time;
    Days         0   HrsiMin     01:23
          Stop            Minimize
To stop a run before its normal termination, click the Stop button on the Run Status window or
press the  key.  Simulation results up until the  time when the run was  stopped will  be
available for viewing. To minimize the SWMM program while a simulation is running, click the
Minimize button on the Run Status window.
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If the analysis runs successfully the ~   icon will appear in the Run Status section of the Status
Bar at  the bottom of SWMM's main window. Any error or warning messages will appear in  a
Status  Report window. If you modify the project after a successful run has been made, the status
flag changes to L-f indicating that the current computed results  no longer apply to the modified
project.


8.4    Troubleshooting Results

When a run ends prematurely, the Run Status dialog will indicate the run was unsuccessful and
direct the user to the Status Report for details. The Status Report will include an error statement,
code, and description of the problem (e.g., ERROR 138: Node TG040 has initial depth greater
than maximum depth). Consult Appendix E for a description of SWMM's error messages. Even if
a run completes successfully, one should check to  insure that the results are reasonable. The
following  are the most common reasons for a run to end prematurely or to contain questionable
results.

Unknown ID Error Message

This message typically appears when an object references another object that was never defined.
An  example would  be a  subcatchment  whose outlet  was  designated  as  A/29, but no such
subcatchment or node with that name exists. Similar situations can exist for incorrect references
made to Curves, Time Series, Time Patterns, Aquifers,  Snow Packs, Transects, Pollutants, and
Land Uses.

File Errors

File errors can occur when:
    •   a file cannot be located on the user's computer
    •   a file being used  has the wrong  format
    •   a file being written cannot be opened because the user does not  have write privileges for
       the directory (folder) where the file is to be stored.

Drainage System Layout Errors

A valid  drainage system layout must obey the following conditions:
    •   An outfall node can have only one conduit link connected  to it.
    •   A flow divider node must have exactly two outflow links.
    •   A node cannot have more than one dummy link connected to it.
    •   Under  Kinematic Wave routing, a junction node can only  have one outflow link and  a
       regulator link cannot be the outflow link of a non-storage node.
    •   Under Dynamic Wave routing there must be at least one outfall node in the network.
An error message will be generated if any of these conditions are  violated.
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Excessive Continuity Errors

When  a run completes successfully, the mass continuity errors  for runoff, flow routing, and
pollutant routing will be displayed in the Run Status window. These errors represent the percent
difference between initial storage + total inflow  and final storage  +  total outflow for the entire
drainage system. If they exceed some reasonable  level, such as 10 percent, then the validity of
the analysis results must be questioned. The most common reasons  for an excessive continuity
error are computational time steps that are too long  or conduits that  are too short.
  Run Status
          Run was successful.
   Continuity Error

     Surface Runofft
     Flow Routing:
     Quality Routing;
-0.27 %
0.10 %
-0.16 %
In addition to the system continuity error, the Status Report produced by a run (see Section 9.1)
will list those nodes of the drainage network that have the largest flow continuity errors.  If the
error  for a  node is excessive,  then  one should  first consider if the node  in question  is  of
importance to the purpose of the simulation. If it is, then further study is warranted to determine
how the error might be reduced.

Unstable Flow Routing Results

Due to the explicit nature of the numerical methods used for Dynamic Wave routing  (and to a
lesser extent, Kinematic Wave routing), the flows in some links or water depths at some nodes
may fluctuate or oscillate significantly at certain  periods  of time  as a result of  numerical
instabilities in the solution method. SWMM does not automatically identify when such conditions
exist,  so it is up to the user to verify the numerical stability of the model and to determine if the
simulation results are valid for the modeling objectives. Time  series plots at key locations in the
network can help identify such situations as can a scatter plot between  a  link's flow and the
corresponding water depth at its upstream node (see Section 9.5, Viewing Results with a Graph).

Numerical instabilities can occur over short durations and may not be apparent when time series
are plotted with a long time interval. When detecting such instabilities, it is recommended that a
reporting time step of 1 minute or less be used, at least for an initial screening  of results.

The run's Status Report  lists the links  having the five highest values of a  Flow Instability  Index
(Fll). This index counts the number of times that the flow value in a link is  higher (or lower) than
the flow in both the previous and subsequent time periods. The index is normalized with respect
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to the expected number of such 'turns' that would occur for a purely random series of values and
can range from 0 to 150.

As an example of how the Flow Instability Index can be used, consider Figure 8-1  shown below.
The solid line plots the flow hydrograph for the link identified as having the highest Fll value (100)
in a dynamic wave flow routing run that used a fixed time step of 30 seconds. The dashed line
shows the hydrograph that  results when a variable time step was used instead, which  is now
completely stable.
         800
         600
      o

      I
400
         200
                                               Fixed Time Step
                                               (Fll = 100)
                                               Variable Time Step
                                               (Fll = 0)
                                                                    10
                                                                      12
                                         Time (hours)
                  Figure 8-1 Flow Instability Index for a flow hydrograph

Flow time series plots for the links having the highest Fll's should be inspected to insure that flow
routing results are acceptably stable.

Numerical instabilities under Dynamic Wave flow routing can be reduced by:
    •   reducing the routing time step
    •   utilizing the variable time step option with a smaller time step factor
    •   selecting to ignore the inertial terms of the momentum equation
    •   selecting the option to lengthen short conduits.
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                      CHAPTER 9 -VIEWING RESULTS
This chapter describes the different ways in which the results of a simulation can be viewed.
These  include a status report, a summary report, various map  views, graphs,  tables,  and a
statistical frequency report.


9.1     Viewing a Status Report

A Status Report is available for viewing after each simulation. It contains:
    •   a summary of the main Simulation Options that are in effect
    •   a list of any error conditions encountered during the run
    •   a summary listing of the project's input data (if requested in the Simulation Options)
    •   a summary of the data read from each rainfall file used in the simulation
    •   a description of each control rule action taken during the simulation (if requested in the
       Simulation Options)
    •   the system-wide mass continuity errors for:
       o   runoff quantity and quality
       o   groundwater flow
       o   conveyance system flow and water quality
    •   the names of the nodes with the highest individual flow continuity errors
    •   the names of the conduits that most often determined the size of the time step used for
       flow routing (only when the Variable Time Step option is used)
    •   the names of the links with the highest Flow Instability Index values
    •   information on the range of routing time steps taken and the  percentage of these that
       were considered steady state.
To view the Status Report select Report » Status from the Main Menu or click the  U button
and select Status Report from the drop-down menu that appears.
To copy selected text from the Status Report to a file or to the Windows Clipboard, first select the
text to copy with the mouse and then choose Edit » Copy To from the Main Menu (or press the
"^ button on the Standard Toolbar).
To save both the entire Status Report and Summary Report (discussed  next) to file, select File
» Export » Status/Summary Report from the Main Menu.
9.2    Viewing Summary Results

SWMM's Summary Results report lists summary results for each subcatchment, node, and link in
the project through a selectable list of tables. To view the various summary results tables, select
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Report » Summary from the Main Menu or click the H  button and select Summary Results
from the drop-down menu that appears. The Summary Results window looks as follows:
HH Summary Results
a > El
Topic: Sub catchment Runoff T Click a column header to sort the column.
Subcatchment
1
2
3
4
5
6
7
8
4
Total Total Total
Precip Runon Evap
in in in
0,00 0,00
2,65 0,00 0,00
2,65 0.00 0,00
2,65 0,00 0,00
2,65 0,00 0,00
2,65 0,00 0,00
2,65 0,00 0,00
2,65 0,00 0,00
Total Total
Infil Runoff
in in
1,16 1,48
1,21 1,43
1,16 1,49
1.16 1,49
1,24 1,40
2,27 0,38
2,14 0,51
2,25 0,40
^
The  drop-down box at the upper left allows you to choose the type of results  to view. The
selection of tables and the results they display are as follows:
Table
Columns
Subcatchment Runoff
Total precipitation (in or mm);
Total run-on from other subcatchments (in or mm);
Total evaporation (in or mm);
Total infiltration (in or mm);
Total runoff depth (in or mm);
Total runoff volume (million gallons or million liters);
Peak runoff (flow units);
Runoff coefficient (ratio of total runoff to total precipitation).
LID Performance
Total inflow volume
Total evaporation loss
Total infiltration loss
Total surface outflow
Total underdrain outflow
Initial storage volume
Final storage volume
Flow continuity error (%)
Note: all quantities are expressed as depths (in or mm) over the LID
unit's surface area.
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Groundwater Summary
Total surface infiltration (in or mm)
Total evaporation (in or mm)
Total lower seepage (in or mm)
Total lateral outflow (in or mm)
Maximum lateral outflow (flow units)
Average upper zone moisture content (volume fraction)
Average water table elevation (ft or m)
Final upper zone moisture content (volume fraction)
Final water table elevation (ft or m)
Subcatchment Washoff
Total  mass of each pollutant washed off the subcatchment (Ibs or
kg).
Node Depth
Average water depth (ft or m);
Maximum water depth (ft or m);
Maximum hydraulic head (HGL) elevation (ft or m);
Time of maximum depth;
Maximum water depth at reporting times (ft or m).
Node Inflow
Maximum lateral inflow (flow units);
Maximum total inflow (flow units);
Time of maximum total inflow;
Total lateral inflow volume (million gallons or million liters);
Total inflow volume (million gallons or million liters);
Flow balance error (0/-
                         Note:  Total inflow  consists  of lateral inflow  plus inflow  from
                         connecting links.
Node Surcharge
Hours surcharged;
Maximum height of surcharge above node's crown (ft or m);
Minimum depth of surcharge below node's top rim (ft or m).
Note: surcharging occurs when water rises above the crown of the
highest conduit and only those conduits that surcharge are listed.
Node Flooding
Hours flooded;
Maximum flooding rate (flow units);
Time of maximum flooding;
Total flood volume (million gallons or million liters);
Peak depth  (for dynamic wave  routing  in ft or m) or peak volume
(1000 ft3 or 1000 m3) of ponded surface water.
Note: flooding refers  to all water that overflows a node, whether it
ponds or not, and only those nodes that flood are listed.
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Storage Volume
Average volume of water in the facility (1000 ft3 or 1000 m3);
Average percent of full storage capacity utilized;
Percent of total stored volume lost to evaporation;
Percent of total stored volume lost to seepage;
Maximum volume of water in the facility (1000 ft3 or 1000 m3);
Maximum percent of full storage capacity utilized;
Time of maximum water stored;
Maximum outflow rate from the facility (flow units).
Outfall Loading
Percent of time that outfall discharges;
Average discharge flow (flow units);
Maximum discharge flow (flow units);
Total volume of flow discharged (million gallons or million liters);
Total mass discharged of each pollutant (Ibs or kg).
Link Flow
Maximum flow (flow units);
Time of maximum flow;
Maximum velocity (ft/sec or m/sec)
Ratio of maximum flow to full normal flow;
Ratio of maximum flow depth to full depth.
Flow Classification
Ratio of adjusted conduit length to actual length;
Fraction of all time steps spent in the following flow categories:
    •  dry on both ends
    •  dry on the upstream end
    •  dry on the downstream end
    •  subcritical flow
    •  supercritical flow
    •  critical flow at the upstream end
    •  critical flow at the downstream end
Fraction of all time steps flow is limited to normal flow;
Fraction of all time steps flow is inlet controlled (for culverts only).
Conduit Surcharge
Hours that conduit is full at:
    •   both ends
    •   upstream end
    •   downstream end
Hours that conduit flows above full normal flow;
Hours that conduit is capacity limited

Note: only conduits with one or more non-zero entries are listed and
a conduit is considered capacity limited if its upstream end is full and
the HGL slope is greater than the conduit slope.
Link Pollutant Loads
Total  mass load (in Ibs  or kg) of each pollutant carried  by the link
over the entire simulation period.
                                           139

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Pumping
                 Percent of time that the pump is on line;
                 Number of pump start-ups;
                 Minimum flow pumped (flow units)
                 Average flow pumped (flow units)
                 Maximum flow pumped (flow units);
                 Total volume pumped (million gallons or million liters);
                 Total energy consumed assuming 100% efficiency (Kw-hrs);
                 Percent of time that the pump operates below its pump curve;
                 Percent of time that the pump operates above its pump curve.
       The summary results displayed in these tables are based  on results found at  every
       computational time step and not just on the results from each reporting time step.
Clicking on the name of an object in the first column of the table will locate that object both in the
Project Browser and on the Study Area Map. Clicking on a column heading will sort the entries in
the table by the values in that column (alternating between ascending and descending order with
each click.
Selecting Edit » Copy To from the Main Menu or clicking ^ on the Standard Toolbar will allow
you to copy the contents of the table to either the Windows Clipboard or to a file. To save both the
entire Status  Report and  all tables of the Summary Report to a file select File » Export »
Status/Summary Report  from the Main Menu.
9.3
Time Series Results
Computed results at each reporting time step for the variables listed in Table 9-1 are available for
viewing on the map and can be plotted, tabulated, and statistically analyzed. These variables can
be viewed only for those subcatchments, nodes, and links that were selected to  have detailed
time series results saved for them. This normally includes all such objects in the project unless
the Reporting  option (under the Options category in the Project Browser) was used to select
specific objects to report on.
                                          140

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                   Table 9-1 Time series variables available for viewing
                                               Link Variables
                                               •   flow rate (flow units)
                                                   average water depth (ft or m)
                                               •   flow velocity (ft/sec or m/sec)
                                               •   volume of water (ft3 or m3)
                                                   capacity (fraction of full area filled by flow
Subcatchment Variables
    rainfall rate (in/hr or mm/hr)
    snow depth (in or mm)
    evaporation loss (in/day or mm/day)
    infiltration loss (in/hr or mm/hr)
    runoff flow (flow units)
•   groundwater flow into the drainage network
    (flow units)
•   groundwater elevation (ft or m)
•   soil moisture in the unsaturated groundwater
    zone (volume fraction)
•   washoff concentration of each pollutant
    (mass/liter)

Node Variables
•   water depth (ft or m above the node invert
    elevation)
    hydraulic head (ft or m, absolute elevation per
    vertical datum)
    stored water volume (including ponded water,
    ft3 or m3)
    lateral inflow (runoff + all other external
    inflows, in flow units)
•   total inflow (lateral inflow + upstream inflows,
    in flow units)
•   surface flooding (excess overflow when the
    node is at full depth, in flow units)
    concentration of each pollutant after any
    treatment applied at the node (mass/liter)
                                                   for conduits; control setting for pumps and
                                                   regulators)
                                                   concentration of each pollutant
                                                   (mass/liter)
                                               System-Wide Variables
                                                   air temperature (degrees F or C)
                                                   potential evaporation (in/day or mm/day)
                                                   actual evaporation (in/day or mm/day)
                                                   total rainfall (in/hr or mm/hr)
                                                •   total snow depth (in or mm)
                                                   average losses (in/hr or mm/hr)
                                                   total runoff flow (flow units)
                                                •   total dry weather inflow (flow units)
                                                •   total groundwater inflow (flow units)
                                                •   total RDM inflow (flow units)
                                                •   total direct inflow (flow units)
                                                •   total external inflow (flow units)
                                                •   total external flooding (flow units)
                                                •   total outflow from outfalls (flow units)
                                                •   total nodal storage volume (ft3 or m3)
9.4    Viewing Results on the Map
There are several ways to view the values of certain input  parameters and simulation results
directly on the Study Area Map:
    •   For the current settings on the Map Browser, the subcatchments, nodes and links of the
       map will be colored according to their respective Map Legends. The map's color coding
       will be updated as a new time period is selected in the Map Browser.
                                           141

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    •   When  the  Flyover  Map  Labeling  program preference is selected  (see  Section  4.9),
       moving the mouse  over  any map  object will  display its ID name and the value of its
       current theme parameter  in a hint-style box.
    •   ID names  and  parameter values can be displayed next to all subcatchments, nodes
       and/or links by selecting the appropriate options on the Annotation page of the  Map
       Options dialog (see  Section 7.12).
    •   Subcatchments, nodes or links meeting a specific criterion can be identified by submitting
       a Map Query (see Section 7.9).
    •   You  can animate the display of results on the network map either forward or backward in
       time by using the controls on the Animator panel of the Map Browser (see Section 4.7).
    •   The  map can be printed, copied to the Windows clipboard, or saved as  a  DXF file or
       Windows metafile (see Section 7.13).


9.5    Viewing Results with a Graph

Analysis results  can be viewed using several different types of graphs. Graphs can be printed,
copied to the Windows  clipboard, or saved to a text file or to a Windows metafile.  The following
types  of graphs can be created from available simulation results:
       Time Series Plot:
                              90.0

                              70.0

                              60.0

                           « 50.0

                           140.0

                           £30.0

                              20.0

                              10.0

                              0.0
                                               Link 1602 Flow (CFS)
                                           2    3    4    S    6
                                               Elapsed Time (hours)
                                          142

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        Profile Plot:
                                    Water Elevation Profile; Node 81009 -16009
                                  at               os
                              105  -
                                      12,000 10,000
8,000  6,(M»
 Distance {ft)
4,000  2,000
                                                                01/01 ,'2002 01:30:00
                                       Link 1600 Flow v. Node 16109 Depth
        Scatter Plot:
70.0
£60.0
0,
o
u- 40.0
O
S 30.0
.E 20.0
10.0
0.0
f
m
m

m
m
	 — . m *
                                         0,5      1      1.5      2
                                                 Node 16109 Depth p|
                    2,5
You can zoom in or out of any graph  by holding down the  key while drawing a zoom
rectangle with the mouse's left button held down. Drawing the rectangle from left to right zooms
in, drawing it from right to left zooms out. The plot can also be panned in any direction by moving
the mouse across the plot with the left button held down

An opened  graph will  normally be redrawn  when  a new simulation  is run.  To  prevent  the
automatic updating of a graph once a  new set of results is computed  you can lock the current
graph by clicking the m icon in the upper left corner of the graph. To unlock the graph, click the
icon again.


Time Series Plots

A Time Series Plot graphs the values overtime of specific combinations of objects and variables.
Up to six time series  can be plotted on the same  graph. When only a single time series is plotted,
and that item has calibration data registered for the plotted variable, then the calibration data will
                                           143

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be plotted along with the simulated results (see Section 5.5 for instructions on how to register
calibration data with a project).

To create a Time Series Plot:

    l. Select  Report »  Graph »  Time Series from the Main  Menu or click lK on  the
       Standard Toolbar.
    2. A Time Series Plot Selection  dialog will appear. Use  it to describe what objects and
       quantities should be plotted.
     Time Series Plot Selection
         Time Periods

         Start Date
          06/27/2002

         o Elapsed Time

         Data Series
      End Date
       06/27/2002

         Date/Time
             Add
Edit
Delete
         Link Cl Flow
             OK
The  Time Series Plot Selection  dialog specifies  a set of objects and their variables whose
computed time series will be graphed in a Time Series Plot. The dialog is used as follows:
    l.  Select a Start Date and End Date for the plot (the default is the entire simulation period).
    2.  Choose whether to show time as Elapsed Time or as Date/Time values.
    3.  Add up to six different data series to the plot by clicking the Add button above the data
       series list box.
    4.  Use the Edit button to make changes to a  selected data series or the Delete button to
       delete a data series.
    5.  Use the Up and Down buttons to  change the order in which the  data  series will be
       plotted.
    6.  Click the OK button to create the plot.
                                           144

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When you click the  Add  or  Edit buttons a Data  Series  Selection dialog will be displayed for
selecting a particular object and variable to plot. It contains the following data fields:
  Data Series Selection


        Specify the object and variable to plot
        (Click an object on the map to select it)


    Object Type      Link


    Object Name     C2
    Variable
    Legend Label
    Axis
     |!  Accept  j|
 Flow
•6. Left
Right
  Cancel
Object Type:      The type of object to plot (Subcatchment, Node, Link or System).

Object Name:     The  ID  name of the object to be  plotted. (This field  is disabled  for System
                  variables).

Variable:         The variable whose time series will be plotted (choices vary by object type).

Legend Label:    The text to use in the legend for the data series. If left blank,  a default label
                  made up of the object type, name, variable  and units will be used (e.g. Link
                  C16Flow(CFS)).

Axis:             Whether to use the left or right vertical axis to plot the data series.
       As you select objects on the Study Area Map or in the Project Browser their types and ID
       names will automatically appear in this dialog.
Click the Accept button to add/update the data series into the plot or click the Cancel button to
disregard your edits. You will then be returned to the Time Series Plot Selection dialog where you
can add or edit another data series.
                                            145

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        To make a precipitation time series display in inverted fashion on a plot, assign it to the
        right axis and after the plot is displayed, use the Graph Options Dialog (see Section 9.6)
        to invert the right axis and expand the scales of both the left and right axes (so  it doesn't
        overlap another data series).
Profile Plots

A Profile Plot displays the variation in simulated water depth with distance over a connected path
of drainage system links and nodes at a particular point in time. Once the plot has been created it
will be automatically updated as a new time period is selected using the Map Browser.

To create a Profile Plot:

    l.  Select Report » Graph » Profile from the  main menu or press  -tj on the Standard
        Toolbar
    2.  A Profile Plot Selection dialog will appear (see below). Use it to identify the path along
        which the profile plot is to be drawn.
  Profile Plot Selection

   Create Profile

   Start Node
    Jl

   End Node
    Outl
         Find Path
Links in Profile


\C2
 C4
      Save Current Profile
                                             X
           OK
The Profile Plot Selection dialog is used to specify a path of connected conveyance system links
along which a water depth profile versus distance should be drawn. To define a path using the
dialog:
    l.  Enter the ID of the upstream node of the first link in the path in the Start Node edit field

        (or click on the node on the Study Area Map and then on the I—J button next to the edit
        field).
                                            146

-------
    2.  Enter the ID of the downstream node of the last link, in the path in the End Node edit field
        (or click the node on the map and then click the      button next to the edit field).
        Click the  Find Path button to have the program automatically identify the path with the
        smallest number of links  between the start and end nodes. These will be listed in the
        Links in Profile box.
        You can insert a new link into the Links in Profile list by selecting the new link either on
       the  Study Area Map or  in the  Project Browser and  then clicking the
       underneath the Links in Profile list box.

    5. Entries in the Links  in Profile list can be deleted  or rearranged by using the
button
        and L—J buttons underneath the list box.
    6.  Click the OK button to view the profile plot.

To save the current set of links listed in the dialog for future use:
    l.  Click the Save Current Profile button.
    2.  Supply a name for the profile when prompted.

To use a previously saved profile:
    l.  Click the Use Saved Profile button.
    2.  Select the profile to use from the Profile Selection dialog that appears.

Profile plots can  also be created before any simulation results are available, to help visualize and
verify the vertical layout of a drainage system. Plots created in this manner will contain a refresh
       tnt\
button _*^J in the upper left corner that can be used to redraw the plot after edits are made to any
elevation data appearing in the plot.


Scatter Plots

A Scatter Plot displays the relationship between a pair of variables,  such as flow rate in a pipe
versus water depth at a node. To create a Scatter Plot:

    l.  Select Report » Graph » Scatter from the main menu or press  liE on the Standard
        Toolbar
    2.  Specify what time interval and what pair  of objects and their variables to plot using the
        Scatter Plot Selection dialog that appears.

The  Scatter  Plot Selection dialog  is  used to select the objects and  variables to be  graphed
against one another in a scatter plot. Use the dialog as follows:
                                            147

-------
 Scatter Plot Select!on

   Start Date
    06/27/2002

    X-Variable
      Object Category
       Nodes

      Object
      J2

      Variable
       Depth
End Date
 06/27/2002

 Y-Variable
   Object Category
   Links

   Object
   C2

   Variable
   Flow
           OK
        Select a Start Date and End Date for the plot (the default is the entire simulation period).
        Select the following choices for the X-variable (the quantity plotted  along the horizontal
        axis):
           a.  Object Category (Subcatchment, Node or Link)
           b.  Object ID (enter a value or click on the object either on the Study Area Map or in
               the Project Browser and then click the
                            button on the dialog)
           c.  Variable to plot (choices depend on the category of object selected).
    3.   Do the same for the Y-variable (the quantity plotted along the vertical axis).
    4.   Click the OK button to create the plot.

9.6     Customizing a Graph's Appearance

To customize the appearance of a graph:
    l.   Make the graph the active window (click on its title bar).
    2.   Select Report » Customize from the Main Menu, or click Hr on the Standard Toolbar,
        or right-click on the graph.
    3.   Use the Graph Options dialog that  appears to customize the appearance of a Time
        Series or Scatter Plot, or use the Profile Plot Options dialog for a Profile Plot.
                                            148

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Graph Options Dialog
The Graph Options dialog is  used to customize the appearance of a time series plot, a scatter
plot, or a freguency plot (described in Section9.8). To use the dialog:
    l.   Select from among the four tabbed pages that cover the following categories of options:
        General, Axes, Legend, and Styles.
   2.   Check the Default box if you wish to use the current settings as defaults for all new
        graphs as well.
   3.   Select OK to accept your selections.
 Graph Options

   General
    Panel Color
Start Background Color
                               White
                               White
    End Background Color     I   I White

    View in 3-D              I  }
    3D Effect Percent
    Main Title
                       25
      I Make these the default options
              OK
                       Cancel
Graph Options - General

The following options can be set on the General page of the Graph Options dialog box:
       Panel Color

       Start Background
       Color

       End Background
                         Color of the panel that contains the graph

                         Starting gradient color of graph's plotting area


                         Ending gradient color of graph's plotting area
                                           149

-------
       Color
        View in 3D
       3D Effect Percent
       Main Title
       Font
Check if graph should be drawn in 3D

Degree to which 3D effect is drawn

Text of graph's main title

Click to set the font used for the main title
The figure below shows a 3D graph with White as the Start Background Color and Sky Blue as
the End Background Color.
   •gj Graph-Link C2 Flow
                            E)
                               LinkC2 Flow(CFS)
                         4    5   6    7   i
                            Elapsed Time (hours)
                        10   11   12
Graph Options - Axes

The Axes page of the Graph Options dialog box adjust the way that the axes are drawn on a
graph. One first selects an axis (Bottom, Left or Right (if present)) to work with and then selects
from the following options:
       Gridlines

       Inverted

       Auto Scale


       Minimum
Displays grid lines on the graph.

Inverts the scale of the right vertical axis.

Fills in the Minimum, Maximum and Increment boxes with an
automatic axis scaling.

Sets the minimum axis value (the minimum data value is shown
in parentheses). Can  be left blank.
                                          150

-------
       Maximum            Sets the maximum axis value (the maximum data value is
                            shown in parentheses). Can be left blank.
       Increment            Sets increment between axis labels. Can be left blank or set to
                            zero for the program to automatically select an  increment.

       Axis Title             Text of axis title.

       Font                 Click to select a font for the axis title.


Graph Options - Legend

The Legend page of the Graph Options dialog box controls how the legend is displayed on the
graph.


       Position              Selects where to place the legend.

       Color                Selects color to use for legend background.

       Check Boxes         If selected, check boxes will appear next to each legend entry,
                            allowing one to make the data series visible or invisible on the
                            graph.

       Framed              Places a frame around the legend.

       Shadowed           Places a shadow behind the legend's text.

       Transparent          Makes the legend background transparent.

       Visible               Makes the legend visible.

       Symbol Width         Selects the width used to draw the symbol  portion of a legend
                            item, as a percentage of the length of the longest legend label.


Graph Options - Styles

The Styles page of the Graph Options dialog box controls how individual  data series (or curves)
are displayed on a graph. To use this page:
    l.  Select  a data series to work with from the Series combo box.
    2.  Edit the title used to identify this series in the legend.
    3.  Click the Font button to change the font used for the legend. (Other legend properties are
       selected on the Legend page of the dialog.)
                                          151

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    4.  Select  a property of the data  series you would  like to  modify (not  all properties are
        available for some types of graphs). The choices are:
            •    Lines
            •    Markers
            •    Patterns
            •    Labels
Profile Plot Options Dialog

The Profile Plot Options dialog is used to customize the appearance of a Profile Plot. The dialog
contains four pages:
  Profile Plot Options
      [ ] Make these the default options
              OK
Cancel
Help
Colors AM
Plot Panel
s Node Labels [ Vertical Scale
Q| White
Plot Background D White
Conduit Interior D White
Water Depth Q Aqua
Display Conduits Only LJ
    Colors:
    Axes:
           Selects the color to use for the plot window panel, the plot background, a conduit's
           interior, and the depth of filled water.
           Includes a "Display Conduits Only" check box that provides a closer look at the water
           levels within conduits by removing all other details from the plot.
            Edits the main and axis titles, including their fonts.
            Selects to display horizontal and vertical axis grid lines.
                                            152

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    Node Labels:
           Selects to display node ID labels either along the plot's top axis, directly on the plot
           above the node's crown height, or both.
           Selects the length of arrow to draw between the node label and the node's crown on
           the plot (use 0 for no arrows).
           Selects the font size of the node ID  labels.
    Vertical Sca/e:
        •   Lets one choose the minimum, maximum, and increment values for the vertical axis
           scale, or have SWMM set the scale automatically. If the increment field contains 0 or
           is left blank the program will automatically select an increment to use.

Check the Default box if you want these options (except the Vertical Scale) to apply to all new
profile plots when they are first created.


9.7     Viewing Results with a Table

Time  series results for selected  variables and objects can also be viewed in a  tabular format.
There are two types of formats available:
    •    Table by Object - tabulates the time series of several variables for a single object (e.g.,
        flow and water depth for a conduit).
"
H] Table -L
Days
0
0
0
0
0
0


ink?
Hours
01:00:00
02:00:00
03:00:00
04:00:00
05:00:00
06:00:00


1 (— ' 1
Flow Dep
(CFS) (ft
0.00 ! 0
2.56 0
4.87 0
5.40 0
5.23 0
1.75 0


B
th *
i 	 i
000000
399179
550729
580890
571036
330089 „

       Table by Variable - tabulates the time series of a single variable for several objects of the
       same type (e.g., runoff fora group of subcatchments).
                                           153

-------
IBB Table - Subcatch Runoff
Days
0
0
0
0
0
0
Hours
01:00:00
02:00:00
03:00:00
04:00:00
05:00:00
06:00:00
Subcatch
2
0.00000 |
1.24382
2.56397
4.52406
2.51151
0,69808
H^H B

Subcatch •*
5
0.00000
1,81482
3.82166
6.56211
3.58567
1,03362 ^

To create a tabular report:
    l.  Select Report » Table from the Main Menu or click El on the Standard Toolbar.
    2.  Choose  the table format (either By Object or By  Variable) from  the sub-menu that
       appears.
    3.  Fill in the Table by Object or Table by Variable dialogs to specify what information the
       table should contain.
The Table by Object dialog is used when  creating a time series table of several variables for a
single object. Use the dialog as follows:
     Table by Object Selection
       Start Date              End Date
        01/01/1998       T     01/02/1998
       Time Format
        Elapsed Time

       Variables
  Object Category
   Links

  Links
          Flow

          Velocity
          Volume
         : Capacity
               OK
Cancel
 Select a Start Date and End Date for the table (the default is the entire simulation period).
    l.   Choose whether to show time as Elapsed Time or as Date/Time values.
                                           154

-------
2.  Choose an Object Category (Subcatchment, Node, Link, or System).
3.  Identify a specific object in the category by clicking the object either on the Study Area
                                                           button on the dialog. Only a
        Map or in the Project Browser and then clicking the
        single object can be selected for this type of table.
    4.   Check off the variables  to be tabulated for the selected object. The  available choices
        depend on the category of object selected.
    5.   Click the OK button to create the table.
The Table by Variable dialog is used when creating a time series table of a single variable for one
or more objects. Use the dialog as follows:
 Table by Variable Select!on
   Start Date               End Date
    01/01/1998       *     01/02/1998
       Time Format
        Elapsed Time

       Variables
                          Object Category
                          Sub catch merits

                          Sub catch merits
      Precipitation
      Snow Depth
      Evaporation
      Infiltration
           OK
                                          Help
l.  Select a Start Date and End Date for the table (the default is the entire simulation period).
2.  Choose whether to show time as Elapsed Time or as Date/Time values.
3.  Choose an Object Category (Subcatchment, Node or Link).
4.  Select  a simulated variable  to  be tabulated.  The  available choices depend on the
    category of object selected.
5.  Identify one or more objects in the category by successively clicking the object either on
    the Study Area Map or in the Project Browser and then clicking the  I
    dialog.
6.  Click the OK button to create the table.
                                                                             button on the
                                        155

-------
Objects already selected can be deleted, moved up in the order or moved down in the order by
clicking the L^ ,  JL. , and I—*  buttons, respectively.
9.8    Viewing a Statistics Report

A Statistics Report can be generated from the time series of simulation results. For a given object
and variable this report will do the following:
    •   segregate  the  simulation  period into a  sequence  of non-overlapping  events, either  by
       day, month, or by flow (or volume) above some minimum threshold value,
    •   compute a statistical value that characterizes each event, such as the mean, maximum,
       or total sum of the variable over the event's time period,
    •   compute summary statistics for the entire set of event values (mean, standard deviation
       and skewness),
    •   perform a frequency analysis on the set of event values.
The frequency analysis of event values will determine the  frequency at which a particular event
value has  occurred  and will also estimate a  return period  for each  event value.  Statistical
analyses of this nature are most suitable for long-term continuous simulation runs.

To generate a Statistics Report:

    l.  Select Report » Statistics from the Main  Menu or click 2  on the Standard Toolbar.
    2.  Fill in the  Statistics Report Selection dialog that appears, specifying the object, variable,
       and event definition to be analyzed.
                                           156

-------
 Statistics Report Selection

   Object Category        Subcatchment

   Object Name         1

   Variable Analyzed       Precipitation

   Event Time Period      Event-Dependent

   Statistic               Mean
     Event Thresholds

      Precipitation

      Event Volume

      Separation Time
                                         0
         OK
                     Cancel

Object Category
Select the category of object to analyze (Subcatchment, Node, Link or System).

Object Name
Enter the ID name of the object to analyze. Instead of typing in an  ID name, you can select the

                                                                         button to select it
object on the Study Area Map or in the Project Browser and then click the
into the Object Name field.

Variable Analyzed
Select the variable to be analyzed. The available choices depend on the object category selected
(e.g., rainfall, losses, or runoff for subcatchments; depth, inflow, or flooding for nodes; depth, flow,
velocity, or capacity for links; water quality for all categories).

Event Time Period
Select  the length of the time period that defines an event. The choices are daily, monthly, or
event-dependent. In the latter case, the event period depends on the number of consecutive
reporting periods where simulation results are above the threshold values defined below.
                                           157

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Statistic
Choose an event statistic to be analyzed. The available choices depend on the choice of variable
to be analyzed and include  such quantities  as mean value,  peak  value, event total,  event
duration, and inter-event time (i.e., the time interval between the midpoints of successive events).
For water quality variables the choices include mean concentration, peak concentration,  mean
loading, peak loading, and event total load.

Event Thresholds
These define minimum values that must be exceeded for an event to occur:
    •   The Analysis  Variable threshold specifies the minimum value of the variable  being
       analyzed that must be exceeded for a time period to  be included in an event.
    •   The Event Volume threshold specifies a minimum flow  volume (or  rainfall volume) that
       must be exceeded for a result to be counted as part of an event.
    •   Separation Time sets the minimum number of hours that must occur between the end of
       one event and  the start  of the next event. Events with fewer hours are  combined
       together. This value applies only to  event-dependent time periods (not to daily or monthly
       event periods).
If a particular type of threshold does not apply, then leave the field blank.

After the choices made on the Statistics Selection dialog form are processed, a Statistics Report
is produced as shown below. It consists of four tabbed pages that contain:
    •   a table of event summary statistics
    •   a table of rank-ordered event periods, including their date, duration, and magnitude
    •   a histogram plot of the chosen event statistic
    •   an exceedance frequency plot of the event values.

The exceedance frequencies included  in the Statistics  Report are computed with respect to the
number of events that occur, not the total number of reporting periods.
                                          158

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2 Statistics - Subcatch 1 Precipitation

! Summary ijjventsj Histogram j Frequency Plot
   SUMMARY   STATISTICS

   Object	 Subcatch  1
   Variable	 Precipitation   (in/hr)
   Event Period ......... Variable
   Event Statistic	 Mean   (in/hr)
   Event Threshold 	 Precipitation  > 0.0000   (in/hr)
   Event Threshold ...... Event Volume > 0.0000 (in)
   Event Threshold 	 Separation Time >= 6.0   (hr)
   Period of Record 	 01/01/1998 to  05/12/2000

   Number of Events 	 226
   Event Frequency*	 0.067
   Minimum Value 	 0.010
   Maximum Value ........ 0,500
   Mean Value 	 0.058
   Std. Deviation ....... 0.058
   Skewness Coeff	 3.001

   *Fraction of all reporting periods belonging to an event.
                                       159

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                  CHAPTER 10 - PRINTING AND COPYING
This chapter describes how to print, copy to the Windows clipboard, or copy to file the contents of
the currently active window in the SWMM workspace. This can include the study area map, a
graph, a table, or a report.

10.1   Selecting a Printer
To select a printer from among your installed Windows printers and set its properties:
    l.  Select File » Page Setup from the Main Menu.
    2.  Click the Printer button on the Page Setup dialog that appears (see below).
    3.  Select a printer from the choices available in the combo box in the Print Setup dialog that
       appears.
    4.  Click the Properties button to select the appropriate printer properties (which vary with
       choice of printer).
    5.  Click OK on each dialog to accept your selections.
     Page Setup
       Margins  Headers/Footers
            Printer.,.
         Paper Size
         Width: 8.5 "
         Height: 11.0 "

         Orientation
         •O- Portrait

         • ' Landscape
Margins (inches)
Left    1.00       Right   1.00
Top    1.50       Bottom 1.00
                                          OK
                           Cancel
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10.2   Setting the Page Format
To format the printed page:
    1.  Select File » Page Setup from the main menu.
    2.  Use the Margins page of the Page Setup dialog form that appears (see above) to:
       •   Select a printer.
       •   Select the paper orientation (Portrait or Landscape).
       •   Set left, right, top, and bottom margins.
    3.  Use the Headers/Footers page of the dialog box (see below) to:
       •   Supply the text for a header that will appear on each page.
       •   Indicate whether the header should be printed or not and how its  text should be
           aligned.
       •   Supply the text for a footer that will appear on each page.
       •   Indicate whether  the footer should  be printed or not and  how  its  text should be
           aligned.
       •   Indicate whether pages should  be numbered.
    4.  Click OK to accept your choices.
     Page Setup
       Margins  Headers/Footers
         Header
         Align:    Left     o Lenter      Right      Enabled

         Footer
         SWMM 5.1
         Align:  o Left     "Center    "Right      Enabled   [7

        Page Numbers     Lower Right
                                           OK
Cancel
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10.3   Print Preview

To  preview a printout select File » Print Preview from the  Main Menu. A Preview form will
appear which shows how each page being printed will appear. While in preview mode, the left
mouse button will re-center and zoom in on the image and the right mouse button will re-center
and zoom out.


10.4   Printing the Current View

To print the contents of the  current window being viewed in the SWMM workspace, either select
File » Print from the Main Menu or click ^ on the Standard  Toolbar. The following views can
be printed:
    •   Study Area Map (at the current zoom level)
    •   Status Report.
    •   Summary report (for the current table being viewed)
    •   Graphs (Time Series, Profile, and Scatter plots)
    •   Tabular Reports
    •   Statistical Reports.


10.5   Copying to the Clipboard or to a File

SWMM can copy the text and graphics of the current window being viewed to  the Windows
clipboard  or to a file. Views that can be copied in  this fashion include the Study Area Map,
summary  report tables, graphs, time series tables,  and statistical  reports. To copy the current
view to the clipboard or to file:
    l.  If the current view is a time series table, select the cells of the table to copy by dragging
       the mouse over them or copy the entire table by selecting Edit » Select All from the
       Main Menu.
    2.  Select Edit  » Copy To from the Main Menu or click the  ^ button on  the Standard
       Toolbar.

    3.  Select choices from the Copy dialog that appears (see below) and click the OK button.

    4.  If copying to file, enter the name of the file in the Save As dialog that appears and click
       OK.
                                          162

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Copy Chart
Copy To
•<>• Clipboard

•[•File
| OK C

Copy As
<3 Bitmap
; Metafile
• '. Data (Text)
lancel Help

Use the Copy dialog as follows to define how you want your data copied and to where:
    l.   Select a destination for the material being copied (Clipboard or File)
    2.   Select a format to copy in:
        •   Bitmap (graphics only)
        •   Metafile (graphics only)
        •   Data (text, selected cells in a table, or data  used to construct a graph)
    3.   Click OK to accept your selections or Cancel to cancel the copy request.

The  bitmap format copies  the individual pixels  of a  graphic. The  metafile format copies  the
instructions used  to create the graphic  and is more suitable for pasting into word processing
documents where the graphic can be re-scaled without losing resolution. When data is copied, it
can be pasted  directly into a spreadsheet program to create customized tables or charts.
                                           163

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                    CHAPTER 11 - FILES USED BY SWMM
This section describes the various files that SWMM can utilize. They include: the project file, the
report and output files, rainfall files, the climate file, calibration data files,  time  series files, and
interface files.  The only file required to run SWMM is the project file; the others are optional.


11.1    Project Files

A SWMM project file is a plain text file that contains all of the data used to describe a study area
and  the  options used to analyze it. The file is organized  into sections, where each section
generally corresponds to a particular category of object used by SWMM. The contents of the file
can be viewed from within SWMM while it is open by selecting Project » Details from the Main
Menu. An existing project file can  be opened by selecting File » Open from the Main Menu and
be saved by selecting File » Save (or File » Save As).

Normally a SWMM user would not edit the  project file directly, since SWMM's graphical user
interface can add, delete, or modify a  project's data and control settings.  However, for large
projects where data currently reside in other electronic formats, such as CAD or CIS files,  it may
be more expeditious to extract data  from these  sources and save  it to a formatted project file
before  running SWMM. The  format of the project file is described in detail  in Appendix D  of this
manual.

After a project file is saved to disk, a settings  file will automatically be saved with it. This file has
the same name as the  project file except that its extension  is .ini (e.g., if the  project file were
named projectl.inp then its  settings  file would have the name project1.ini). It contains various
settings used by SWMM's graphical  user interface, such as  map display options, legend  colors
and intervals, object default values, and calibration file  information. Users should not edit this file.
A SWMM project will still  load and run even if the settings file is missing.


11.2    Report and Output Files

The report file  is a plain text  file created after every  SWMM run that contains the  contents of both
the Status Report and  all  of the tables  included in the Summary  Results  report. Refer to
Sections 9.1 and 9.2 to review their contents.

The output file is a binary file that contains the numerical results from a successful  SWMM run.
This file  is used by SWMM's user interface to interactively create time series plots and tables,
profile plots, and statistical analyses of a simulation's results.

Whenever a successfully run project is either saved or closed,  the report and output files are
saved with the same name  as the  project file, but with extensions of .rpt and .out This will
happen automatically if the program preference Prompt to Save Results is turned off (see Section
4.9). Otherwise the user is asked if the current results should be saved or not. If results are saved
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then the next time the project is opened, the results from these files will automatically be available
for viewing.


11.3   Rainfall Files

SWMM's rain gage objects can utilize rainfall data stored in external rainfall files. The program
currently recognizes the following formats for storing such data:
    •  Hourly and fifteen  minute precipitation data from  over 5,500 reporting stations retrieved
       using NOAA's  National  Climatic Data  Center (NCDC) Climate  Data Online service
       (www.ncdc.noaa.gov/cdo-web') (space-delimited text format only).
    •  The older DS-3240 and related formats used for hourly precipitation by NCDC.
    •  The older DS-3260 and related formats used for fifteen minute precipitation by NCDC.
    •  HLY03  and HLY21  formats for  hourly  rainfall  at  Canadian stations, available from
       Environment Canada at www.climate.weather.gc.ca.
    •  FIF21 format for fifteen minute rainfall at Canadian  stations, also  available online from
       Environment Canada.
    •  a standard user-prepared format where each  line  of the file contains the station ID, year,
       month, day, hour,  minute, and non-zero precipitation reading, all  separated  by one or
       more spaces.

When requesting  data from NCDC's online service, be sure to specify the TEXT format option,
make sure that the data flags are included, and, for 15-minute data, select the QPCP option and
nottheQGAG one.

An excerpt from a sample user-prepared Rainfall file is as follows:

    STAOl   2004  6   12   00   00   0.12
    STA01   2004  6   12   01   00   0.04
    STAOl   2004  6   22   16   00   0.07

This format can also accept multiple stations within the same file.

When a rain gage is designated as receiving its rainfall data from a file, the user must supply the
name of the file and the name of the recording  station referenced in the file.  For the standard
user-prepared  format,  the  rainfall type (e.g., intensity  or volume),  recording time interval, and
depth units  must also be  supplied  as  rain gage properties.  For  the  other file types these
properties are defined by their respective file format and are automatically recognized by SWMM.


11.4   Climate Files

SWMM can use an external climate file that contains daily air temperature, evaporation, and wind
speed data. The program currently recognizes the following formats:
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    •   Global Historical Climatology Network - Daily (GHCN-D) files (TEXT output  format)
       available from NOAA's  National Climatic Data  Center (NCDC) Climate Data Online
       service at www.ncdc.noaa.gov/cdo-web.
    •   Older NCDC  DS-3200 or DS-3210 files.
    •   Canadian climate files available from Environment Canada at
       www.climate.weather.gc.ca.
    •   A user-prepared climate file where each line contains a recording station name, the year,
       month, day, maximum temperature, minimum  temperature, and optionally, evaporation
       rate, and wind speed. If no  data are available for any of these items on a given date, then
       an asterisk should be entered as its value.
When a climate file has days with missing values,  SWMM will use the value from the most recent
previous day with a recorded value.
  F":
       For a user-prepared climate file, the data  must  be in the same units as the project  being
       analyzed. For US units, temperature is in degrees  F, evaporation is in inches/day, and
       wind speed is in miles/hour. For metric units, temperature is in degrees C, evaporation is
       in mm/day, and wind speed is in  km/hour.

11.5   Calibration Files
Calibration  files  contain measurements of variables  at one or more locations that  can  be
compared with simulated values in  Time Series Plots. Separate files can be used for each of the
following:
    •   Subcatchment Runoff
    •   Subcatchment Groundwater Flow
    •   Subcatchment Groundwater Elevation
    •   Subcatchment Snow Pack Depth
    •   Subcatchment Pollutant Washoff
    •   Node Depth
    •   Node Lateral Inflow
    •   Node Flooding
    •   Node Water Quality
    •   Link Flow
    •   Link Velocity
    •   Link Depth
Calibration files are registered to a project by selecting Project » Calibration  Data from the
main menu (see Section 5.7).
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The format of the file is as follows:
    l.  The name of the first object with calibration data is entered on a single line.
    2.  Subsequent lines contain the following recorded measurements for the object:
           •    measurement date (month/day/year, e.g., 6/21/2004) or  number of whole days
               since the start of the simulation
           •    measurement time (hours:minutes) on the measurement date or relative to the
               number of elapsed days
           •    measurement value (for pollutants, a value is required for each pollutant).
    3.  Follow the same sequence for any additional objects.
An  excerpt from an  example calibration  file is  shown  below. It contains flow  values  for two
conduits: 1030 and 1602. Note that a semicolon can  be used to begin a comment. In this
example, elapsed time rather than the actual measurement date was used.
; Flows for Selected
; Conduit Days Time
r
1030
0
0
0
0
0
1602
0
0
0
0

0
0
0
1
1

0
0
1
1
Conduits
Flow

15
30
45
00
15

15
30
00
15

0
0
23
94



.88
.58
115.37

5.
38
67
68

76
.51
.93
.01
11.6   Time Series Files

Time  series files are external text files that contain  data for SWMM's time series objects.
Examples of time  series data include rainfall, evaporation, inflows to nodes of the drainage
system, and water stage at outfall boundary nodes. The file must be created and edited outside of
SWMM, using a text editor or spreadsheet program. A time series file can be linked to  a specific
time series object using SWMM's Time Series Editor (see Section C.19).

The format of a time series file consists of one time series value per line. Comment lines can be
inserted anywhere  in the file as long as they begin with a semicolon.  Time series values can
either be  in date / time / value format or in time / value format, where each entry is separated by
one or more spaces or tab characters. For the date / time / value format, dates are entered as
                                          167

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month/day/year (e.g., 7/21/2004) and times as 24-hour military time (e.g., 8:30 pm is 20:30). After
the first date, additional dates need only be entered whenever a new day occurs. For the time /
value format, time can either be decimal hours or military time since the start of a simulation (e.g.,
2 days, 4 hours and 20 minutes can be entered as either 52.333 or 52:20). An example of a time
series file is shown  below:
; Rainfall Data
07/01/2003




07/06/2003




00
00
00
00
01
14
14
15
18
18
for Gage Gl
00
15
30
45
00
30
45
00
15
30
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
00000
03200
04800
02400
0100
05100
04800
03000
01000
00800
        In earlier releases of SWMM 5, a time series file was required to have two header lines of
        descriptive  text at the start of the file that did not have to begin with the semicolon
        comment character. These files can still be used as long as they are modified by inserting
        a semicolon at the front of the first two lines.

        When preparing rainfall time series files, it is only necessary to enter periods with  non-
        zero rainfall amounts.  SWMM interprets the rainfall value as a constant value lasting over
        the  recording interval  specified for the rain  gage which utilizes the time series.  For all
        other types of time series, SWMM uses interpolation to estimate values at times that fall
        in between the recorded values.
11.7    Interface Files

SWMM can use  several different kinds of interface files that contain either externally imposed
inputs  (e.g., rainfall  or infiltration/inflow hydrographs)  or the results  of previously  run  analyses
(e.g., runoff or routing results). These files can help speed up simulations, simplify comparisons
of different loading scenarios, and allow large study areas to be broken up into smaller areas that
can  be analyzed individually. The different types of interface files that are currently  available
include:
    •   rainfall interface file
    •   runoff interface file
    •   hot start file
    •   RDM interface file
    •   routing interface files
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Consult Section 8.1, Setting Simulation Options, for instructions on how to specify interface files
for use as input and/or output in a simulation.


Rainfall and Runoff Files

The  rainfall  and runoff interface files are binary files created internally by SWMM that can  be
saved and reused from one analysis to the next.

The rainfall interface file collates a series of separate rain gage files into a single rainfall data file.
Normally a temporary file of this type is created for every SWMM analysis that  uses external
rainfall data  files and is then deleted after the  analysis is completed. However, if the same rainfall
data are being used with  many different analyses, requesting SWMM to save the rainfall interface
file after the  first run and then reusing this file in subsequent runs can save computation time.

 (j)
 W    The rainfall interface file should not be confused with a rainfall data file.  The latter is  an
       external text file that provides rainfall  time series data for a single rain gage. The former
       is a binary file created internally by SWMM that processes  all of the rainfall data files
       used by a project.

The runoff interface file can  be used to save the runoff results generated from a simulation  run. If
runoff is  not affected in future runs,  the  user can  request that SWMM use this  interface  file to
supply runoff results without having to repeat the runoff calculations again.


Hot Start Files

Hot start files are  binary files created by SWMM that contain the full  hydrologic,  hydraulic and
water quality state of the  study area at the end of a run.  The following information is saved to the
file:
    •   the ponded depth and its water quality for each subcatchment
    •   the pollutant mass buildup on  each subcatchment
    •   the infiltration state of each subcatchment
    •   the conditions of  any snowpack on each subcatchment
    •   the  unsaturated zone moisture content, water table elevation,  and groundwater outflow
       for each subcatchment that has a groundwater zone defined for it
    •   the water depth, lateral inflow, and water quality at each node of the system
    •   the flow rate, water depth, control setting and water quality in each link of the system.
The hydrologic state of any LID units  is not saved. The hot start file saved after a run can be used
to define the initial  conditions for a subsequent run.

Hot start files can  be used to avoid the initial numerical instabilities that sometimes occur under
Dynamic Wave routing. For this purpose they are typically generated by imposing a constant set
of base flows (for a natural channel network) or set  of dry weather sanitary flows (for a  sewer
                                            169

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network) over some startup period of time. The resulting hot start file from this run is then used to
initialize a subsequent run where the inflows of real interest are imposed.

It is also possible to both use and save a hot start file in a single run, starting off the run with one
file and saving the ending  results to another.  The  resulting file can then serve  as the  initial
conditions for a subsequent run if need be. This technique can be used to divide up extremely
long continuous simulations into more manageable pieces.

Instructions to save and/or  use a hot start file can be issued when editing the Interface Files
options available  in the Project Browser (see Sections.1, Setting  Simulation Options). One can
also use the  File » Export » Hot Start File Main Menu command to  save the results of a
current run at any particular time period to a hot start file. However, in this case only the results
for nodes, links and groundwater elevation will be saved.


RDM Files

The RDM interface file contains a time  series of rainfall-dependent infiltration/inflow  flows for a
specified set  of drainage system nodes. This file can be generated from a previous SWMM run
when Unit Hydrographs and  nodal RDM inflow data have been defined for the project, or it can be
created outside of SWMM using some other source of RDM  data (e.g., through measurements or
output from a different  computer program). RDM files generated  by SWMM are saved in a binary
format. RDM files created outside of SWMM  are text  files with the same format used for routing
interface files discussed below, where Flow is the only variable contained  in the file.


Routing Files

A  routing interface file stores a time  series  of flows and pollutant  concentrations that  are
discharged from the outfall nodes of drainage system model. This file can serve as the source of
inflow to another drainage system model that is connected at the outfalls  of the first system. A
Combine utility is  available on the File menu that will combine pairs of routing interface files  into a
single  interface file. This allows very large systems to be  broken into smaller sub-systems that
can  be analyzed  separately and linked together through the routing interface file.  Figure 11.1
below illustrates this concept.

A single SWMM run can utilize an outflows routing file to  save results generated at a system's
outfalls, an inflows routing file to supply hydrograph and pollutograph inflows at selected nodes,
or both.
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                     J>roi1.inp
                     re outl .dat
  proj2.inp
save out2.dat
                                      Combine
                            out1.dat + out2.dat » inp3.dat
                                       projS.inp
                                     use inp3.dat
                      Figure 11-1 Combining routing interface files

RDM / Routing File Format
RDM interface files and routing interface files have the same text format:
    l.  the first line contains the keyword "SWMM5" (without the quotes)
    2.  a line of text that describes the file (can be blank)
    3.  the time step used for all inflow records (integer seconds)
    4.  the number of variables stored in the file, where the first variable must always be flow
       rate
    5.  the name  and units of each variable (one per line), where flow rate is the first variable
       listed and is always named FLOW
    6.  the number of nodes with recorded inflow data
    7.  the name of each node (one per line)
    8.  a line of text that provides  column headings for the data to follow (can be blank)
    9.  for each node at each time step, a line with:
       •   the name of the node
       •   the date (year, month, and day separated by spaces)
       •   the time of day (hours, minutes, and seconds separated by spaces)
       •   the flow rate followed by the concentration of each quality constituent
Time periods with no values at any node can be skipped. An  excerpt from an RDM / routing
interface file is shown below.
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SWMM5
Example File
300
1
FLOW CFS
2
Nl
N2
Node Year Mon Day Hr Min Sec Flow
Nl   2002 04  01  00 20  00  0.000000
N2   2002 04  01  00 20  00  0.002549
Nl   2002 04  01  00 25  00  0.000000
N2   2002 04  01  00 25  00  0.002549
                                   172

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                    CHAPTER 12 - USING ADD-IN TOOLS
SWMM 5 has the ability to launch external applications from its graphical user interface that can
extend its capabilities. This section describes how such tools can be registered and share data
with SWMM 5.
12.1    What Are Add-In Tools

Add-in tools are third party applications that users can add to the Tools menu of the main SWMM
menu bar and be launched  while  SWMM is still running.  SWMM can  interact  with these
applications to  a limited degree by exchanging data through its pre-defined files (see Chapter 11)
or through the Windows clipboard. Add-in tools can provide  additional modeling capabilities to
what SWMM already offers. Some examples of useful add-ins might include:
    •   a tool that performs a statistical  analysis of long-term rainfall data prior to adding it to a
       SWMM rain gage,
    •   an external spreadsheet program that would facilitate the editing of a  SWMM data set,
    •   a unit hydrograph estimator program that would derive the R-T-K parameters for a set of
       RDM unit hydrographs which could then  be copied and pasted directly into SWMM's Unit
       Hydrograph Editor,
    •   a post-processor program  that uses SWMM's hydraulic results to compute  suspended
       solids removal through a storage unit,
    •   a third-party dynamic flow routing program used as a substitute for SWMM's own internal
       procedure.

The screenshot below shows what the Tools menu might look like after several add-in tools have
been registered with it. The Configure Tools option is used to add, delete, or modify add-in tools.
The options below this are  the individual tools that have been made available (by this particular
user) and can be launched by selecting them from the menu.

     SWMM 5.1
   File  Edit  View   Project  Report  Tools  Window  Help

                      to *4  ?{]
   Project
Map
     -Title/Notes
       Options
     •••• Climatology
     t> • Hydrology
     >• Hydraulics
                                Program Preferences...
Map Display Options,..
ConfigureTools...

Design Storm Wizard
Excel Editor
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12.2   Configuring Add-In Tools
To configure  one's personal collection of add-in tools, select Configure Tools from the Tools
menu. This will bring up the Tool Options dialog as shown below. The dialog lists the currently
available tools and has command buttons for adding a new tool and for deleting or editing an
existing  tool.  The  up and  down  arrow buttons  are  used to change the order in  which the
registered tools are listed on the Tools menu.
 Tool Options

   Tools
    Excel Editor
    Climate Adjustment Tool
Whenever the Add or Edit button is clicked on this dialog a Tool Properties dialog will appear.
This dialog is  used to describe the properties of the  new tool being added or the existing tool
being edited. The data entry fields of the Tool Properties dialog consist of the following:

Tool Name
This is the name to be used for the tool when it is displayed in the Tools Menu.

Program
Enter the full path name to the program that will  be launched when the tool is selected. You can
click the IJ™J button to  bring up a standard Windows file selection dialog  from which  you can
search for the tool's executable file name.

Working Directory
This field contains the name of the directory that will be used as the working directory when the
tool is launched. You can click the '-1 button to bring up a standard directory selection dialog
from which you  can search for the desired directory. You can  also enter the macro  symbol
$PROJDIR to utilize the current SWMM project's  directory or $SWMMDIR  to use the directory
where the SWMM 5 executable resides.  Either of these  macros can also be inserted into the
Working Directory field by selecting its name in the  list of macros provided on the dialog and then
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clicking the L_U button. This field can be left blank, in which case the system's current directory
will be used.
 Tool Properties
   Program

   Working
   Directory

   Parameters
   Macros:
   Tool Name     Excel Editor
 Files (x86)\Microsoft Orfice\Officel2\EXCEL.EXE
SIN P FILE
$PROJDIR
$SWMMDIR
$INFFILE
53PIFILZ:
$OUIFILZ
$RIFFILI
Project directory
SWMM directory
SWMM input file
SWMM report file
SWMM output file
SWMM runoff interface
file
                   Disable SWMM while executing

                   Update SWMM after closing
                                OK
                           Cancel
Help
Parameters
This field contains the list of command line arguments that the tool's executable program expects
to see when it is launched.  Multiple parameters can be entered  as long as they are separated by
spaces. A number of special macro symbols have been pre-defined, as listed in the Macros list
box of the dialog, to simplify the process of listing the command line parameters. When one of
these macro symbols is inserted into the list of parameters, it will be expanded to its true value
when the tool is launched. A specific macro symbol can either be typed into the Parameters field
or be selected from  the Macros list (by clicking on  it) and then added to the  parameter list by

clicking the I—J button. The available macro symbols and their meanings are:
$PROJDIR

$SWMMDIR

$INPFILE
    The directory where the current SWMM project file resides.

    The directory where the SWMM 5 executable is installed.

    The name of a temporary file containing the current project's data that is
    created just before the tool is launched.
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$RPTFILE            The name of a temporary  file that is created just before the tool is
                     launched and can be displayed after the tool closes by using the Report
                     » Status command from the main SWMM menu.

$OUTFILE            The name of a temporary file to which the tool can write simulation results
                     in the same format  used by SWMM  5, which can then be displayed after
                     the tool closes in the same fashion as if a SWMM run were made.

$RIFFILE            The name of the Runoff Interface File, as specified in the Interface Files
                     page of the Simulation Options dialog, to  which runoff simulation results
                     were saved from a previous SWMM run (see Sections 8.1       Setting
                     Simulation Options and 11.7lnterface Files).

As an example of how the macro expansion works, consider the entries  in  the Tool Properties
dialog shown previously. This Spreadsheet  Editor tool wants to launch Microsoft Excel and pass it
the  name of the SWMM input data  file to  be  opened by Excel. SWMM will issue  the following
command line to do this
C:\Program Files  (x86)\Microsoft Office\Officel2\EXCEL.EXE  $INPFILE

where the string $INPFILE will be replaced by the name of the temporary file that SWMM
creates internally that contains the current project's data.

Disable SWMM while executing
Check this option if SWMM should  be  hidden  and disabled  while  the tool is executing. Normally
you will need to employ this option if the tool produces a  modified  input file or output file, such as
when the $INPFILE or $OUTFILE  macros are  used  as command line parameters. When this
option is enabled, SWMM's main window will be hidden from view  until the tool is terminated.

Update SWMM after closing
Check this option if SWMM should be  updated after the tool finishes executing. This option can
only be  selected if the option  to disable SWMM while the  tool is executing was first selected.
Updating can occur in two ways. If the $INPFILE macro was used as a command line parameter
for the tool and the corresponding temporary input file produced by SWMM was updated by the
tool, then the  current  project's data will be  replaced with the data  contained in  the  updated
temporary input file. If the $OUTFILE  macro was used  as  a command line parameter, and its
corresponding file is found to contain a valid set of output results after the tool closes, then the
contents of this file will  be used to display simulation results within  the SWMM workspace.

Generally speaking, the suppliers of third-party  tools  will provide instructions on what settings
should be used in the Tool Properties dialog to properly register their tool with SWMM.
                                          176

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                APPENDIX A - USEFUL TABLES
A.1
Units of Measurement
PARAMETER
Area (Subcatchment)
Area (Storage Unit)
Area (Ponding)
Capillary Suction
Concentration
Decay Constant (Infiltration)
Decay Constant (Pollutants)
Depression Storage
Depth
Diameter
Discharge Coefficient:
Orifice
Weir
Elevation
Evaporation
Flow
Head
Hydraulic Conductivity
Infiltration Rate
Length
Manning's n
Pollutant Buildup
Rainfall Intensity
Rainfall Volume
Slope (Subcatchments)
Slope (Cross Section)
Street Cleaning Interval
Volume
Width
US CUSTOMARY
acres
square feet
square feet
inches
mg/L (milligrams/liter)
ug/L (micrograms/liter)
Count/L (counts/liter)
1 /hours
1/days
inches
feet
feet
dimensionless
CFS/footn
feet
inches/day
CFS (cubic feet / second)
GPM (gallons / minute)
MGD (million gallons/day)
feet
inches/hour
inches/hour
feet
seconds/meter173
mass/length
mass/acre
inches/hour
inches
percent
rise/run
days
cubic feet
feet
SI METRIC
hectares
square meters
square meters
millimeters
mg/L
ug/L
Count/L
1 /hours
1/days
millimeters
meters
meters
dimensionless
CMS/metern
meters
millimeters/day
CMS (cubic meters/second)
LPS (liters/second)
MLD (million liters/day)
meters
millimeters/hour
millimeters/hour
meters
seconds/meter173
mass/length
mass/hectare
millimeters/hour
millimeters
percent
rise/run
days
cubic meters
meters
                            177

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A.2
Soil Characteristics
Soil Texture Class
Sand
Loamy Sand
Sandy Loam
Loam
Silt Loam
Sandy Clay Loam
Clay Loam
Silty Clay Loam
Sandy Clay
Silty Clay
Clay
K
4.74
1.18
0.43
0.13
0.26
0.06
0.04
0.04
0.02
0.02
0.01
Y
1.93
2.40
4.33
3.50
6.69
8.66
8.27
10.63
9.45
11.42
12.60
4>
0.437
0.437
0.453
0.463
0.501
0.398
0.464
0.471
0.430
0.479
0.475
FC
0.062
0.105
0.190
0.232
0.284
0.244
0.310
0.342
0.321
0.371
0.378
WP
0.024
0.047
0.085
0.116
0.135
0.136
0.187
0.210
0.221
0.251
0.265
        K   =  saturated hydraulic conductivity, in/hr
        *F   =  suction head, in.
        <|>   =  porosity, fraction
        FC =  field capacity, fraction
        WP =  wilting point, fraction

        Source: Rawls, W.J. et al., (1983). J. Hyd. Engr., 109:1316.

        Note:   The following relation between T and K can be derived
                from this table:
                   T = 3.23 K-°328  (R2 = 0.9)
                                             178

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A.3    NRCS Hydrologic Soil Group Definitions
       Group
Meaning
Saturated
Hydraulic
Conductivity
(in/hr)
                Low runoff potential.
                Water is transmitted freely through the soil. Group A soils
                typically have less than 10 percent clay and more than 90
                percent sand or gravel and have gravel or sand textures.
                                                       >1.42
       B
Moderately low runoff potential.
Water transmission through the soil is unimpeded. Group B
soils typically have between  10  percent and  20  percent
clay and 50 percent to 90 percent sand and have loamy
sand or sandy loam textures.
0.57-1.42
                Moderately high runoff potential.
                Water transmission through the soil is somewhat restricted.
                Group C soils typically have between  20 percent and  40
                percent clay and less than 50 percent sand and have loam,
                silt loam, sandy  clay loam, clay loam,  and silty clay  loam
                textures.
                                                       0.06 - 0.57
                High runoff potential.
                Water movement through the  soil  is  restricted  or very
                restricted. Group D soils typically  have greater  than  40
                percent clay, less than 50 percent sand, and have clayey
                textures.
                                                       <0.06
       Source:  Hydrology  National  Engineering  Handbook,  Chapter 7, Natural  Resources
       Conservation Service, U.S. Department of Agriculture, January 2009.
                                          179

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A.4    SCS Curve Numbers1
Land Use Description

Cultivated land
Without conservation treatment
With conservation treatment
Pasture or range land
Poor condition
Good condition
Meadow
Good condition
Wood or forest land
Thin stand, poor cover, no mulch
Good cover2
Open spaces, lawns, parks, golf courses, cemeteries,
etc.
Good condition: grass cover on
75% or more of the area
Fair condition: grass cover on
50-75% of the area
Commercial and business areas (85% impervious)
Industrial districts (72% impervious)
Residential3
Average lot size (% Impervious4)
1/8 ac or less (65)
1 Mac (38)
1/3ac(30)
1/2ac(25)
1 ac (20)
Paved parking lots, roofs, driveways, etc.5
Streets and roads
Paved with curbs and storm sewers5
Gravel
Dirt
Hydrologic Soil Group
A

72
62

68
39

30

45
25



39

49
89
81


77
61
57
54
51
98

98
76
72
B

81
71

79
61

58

66
55



61

69
92
88


85
75
72
70
68
98

98
85
82
C

88
78

86
74

71

77
70



74

79
94
91


90
83
81
80
79
98

98
89
87
D

91
81

89
80

78

83
77



80

84
95
93


92
87
86
85
84
98

98
91
89
Source: SCS Urban Hydrology for Small Watersheds, 2nd Ed., (TR-55), June 1986.

Footnotes:
i.  Antecedent moisture condition II.
2.  Good cover is protected from grazing and litter and brush cover soil.
                                         180

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    Curve numbers are computed assuming that the runoff from the house and driveway is
    directed toward the street with a minimum of roof water directed to lawns where additional
    infiltration could occur.
    The remaining pervious areas (lawn) are considered to be in good pasture condition for these
    curve numbers.
    In some warmer climates of the country a curve number of 95 may be used.
A.5    Depression Storage
Impervious surfaces
Lawns
Pasture
Forest litter
0.05- 0.10 inches
0.10- 0.20 inches
0.20 inches
0.30 inches
       Source: ASCE, (1992). Design & Construction of Urban  Stormwater
       Management Systems, New York, NY.
                                         181

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A.6    Manning's n - Overland Flow
Surface
Smooth asphalt
Smooth concrete
Ordinary concrete lining
Good wood
Brick with cement mortar
Vitrified clay
Cast iron
Corrugated metal pipes
Cement rubble surface
Fallow soils (no residue)
Cultivated soils
Residue cover < 20%
Residue cover > 20%
Range (natural)
Grass
Short, prairie
Dense
Bermuda grass
Woods
Light underbrush
Dense underbrush
n
0.011
0.012
0.013
0.014
0.014
0.015
0.015
0.024
0.024
0.05
0.06
0.17
0.13
0.15
0.24
0.41
0.40
0.80
       Source: McCuen, R. et al. (1996), Hydrology, FHWA-SA-
       96-067,  Federal Highway Administration, Washington,
       DC
                                         182

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A.7    Manning's n - Closed Conduits
Conduit Material
Asbestos-cement pipe
Brick
Cast iron pipe
- Cement-lined & seal coated
Concrete (monolithic)
- Smooth forms
- Rough forms
Concrete pipe
Corrugated-metal pipe
(1/2-in. x2-2/3-in. corrugations)
- Plain
- Paved invert
- Spun asphalt lined
Plastic pipe (smooth)
Vitrified clay
- Pipes
- Liner plates
Manning n
0.011 -0.015
0.013-0.017
0.011 -0.015
0.012-0.014
0.015-0.017
0.011 -0.015
0.022 - 0.026
0.018-0.022
0.011 -0.015
0.011 -0.015
0.011 -0.015
0.013-0.017
       Source: ASCE (1982). Gravity Sanitary Sewer Design and Construction, ASCE Manual of
       Practice No. 60, New York, NY.
                                        183

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A.8    Manning's n - Open Channels
Channel Type
Lined Channels
- Asphalt
- Brick
- Concrete
- Rubble or riprap
- Vegetal
Excavated or dredged
- Earth, straight and uniform
- Earth, winding, fairly uniform
- Rock
- Unmaintained
Natural channels (minor streams, top width at flood
stage < 100ft)
- Fairly regular section
- Irregular section with pools
Manning n

0.013-0.017
0.012-0.018
0.011 -0.020
0.020 - 0.035
0.030 - 0.40

0.020 - 0.030
0.025 - 0.040
0.030 - 0.045
0.050-0.140

0.030-0.070
0.040-0.100
       Source: ASCE (1982). Gravity Sanitary Sewer Design and Construction, ASCE Manual of
       Practice No. 60, New York, NY.
                                        184

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A.9    Water Quality Characteristics of Urban Runoff
Constituent
TSS (mg/L)
BOD (mg/L)
COD (mg/L)
Total P (mg/L)
Soluble P (mg/L)
TKN (mg/L)
N02/N03-N (mg/L)
Total Cu (ug/L)
Total Pb (ug/L)
Total Zn (ug/L)
Event Mean Concentrations
180-548
12-19
82-178
0.42 - 0.88
0.15-0.28
1.90-4.18
0.86 - 2.2
43-118
182-443
202 - 633
       Source: U.S.  Environmental Protection Agency. (1983). Results of the
       Nationwide Urban Runoff Program (NURP), Vol. 1, NTIS PB 84-185552),
       Water Planning Division, Washington, DC.
                                         185

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A.10   Culvert Code Numbers

       Circular Concrete
       1   Square edge with headwall
       2   Groove end with headwall
       3   Groove end projecting

       Circular Corrugated Metal Pipe
       4   Headwall
       5   Mitered to slope
       6   Projecting

       Circular Pipe, Beveled Ring Entrance
       7   45 deg. bevels
       8   33.7 deg. bevels

       Rectangular Box; Flared Wingwalls
       9   30-75 deg. wingwall flares
       10  90 or 15 deg. wingwall flares
       11  0 deg.  wingwall flares (straight sides)

       Rectangular Box;Flared Wingwalls and Top Edge Bevel:
       12  45 deg flare; 0.43D top edge bevel
       13  18-33.7 deg. flare; 0.083D top edge bevel

       Rectangular Box, 90-deg Headwall, Chamfered / Beveled Inlet Edges
       14  chamfered 3/4-in.
       15  beveled 1 /2-in/ft at 45 deg (1:1)
       16  beveled 1-in/ft at 33.7 deg (1:1.5)

       Rectangular Box, Skewed Headwall, Chamfered / Beveled Inlet Edges
       17  3/4" chamfered edge, 45 deg skewed headwall
       18  3/4" chamfered edge, 30 deg skewed headwall
       19  3/4" chamfered edge, 15 deg skewed headwall
       20  45 deg beveled edge, 10-45 deg skewed headwall

       Rectangular Box, Non-offset Flared Wingwalls,  3/4" Chamfer at Top of Inlet
       21  45 deg (1:1) wingwall flare
       22  8.4 deg (3:1) wingwall flare
       23  18.4 deg (3:1) wingwall flare, 30 deg inlet skew

       Rectangular Box, Offset Flared Wingwalls,  Beveled  Edge at Inlet Top
       24  45 deg (1:1) flare, 0.042D top edge bevel
       25  33.7 deg (1.5:1) flare, 0.083D top edge bevel
       26  18.4 deg (3:1) flare, 0.083D top edge bevel
                                        186

-------
Corrugated Metal Box
27  90 deg headwall
28  Thick wall projecting
29  Thin wall projecting

Horizontal Ellipse Concrete
30  Square edge with headwall
31  Grooved end with headwall
32  Grooved end projecting

Vertical Ellipse Concrete
33  Square edge with headwall
34  Grooved end with headwall
35  Grooved end projecting

Pipe Arch, 18" Corner Radius, Corrugated Metal
36  90 deg headwall
37  Mitered to slope
38  Projecting

Pipe Arch, 18" Corner Radius, Corrugated Metal
39  Projecting
40  No bevels
41  33.7 deg bevels

Pipe Arch, 31" Corner Radius,Corrugated Metal
42  Projecting
43  No bevels
44  33.7 deg. bevels

Arch, Corrugated Metal
45  90 deg headwall
46  Mitered to slope
47  Thin wall projecting

Circular Culvert
48  Smooth tapered inlet throat
49  Rough tapered inlet throat

Elliptical Inlet Face
50  Tapered  inlet, beveled edges
51  Tapered  inlet, square edges
52  Tapered  inlet, thin edge projecting
                                  187

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Rectangular
53  Tapered inlet throat

Rectangular Concrete
54  Side tapered, less favorable edges
55  Side tapered, more favorable edges
56  Slope tapered, less favorable edges
57  Slope tapered, more favorable edges
                                  188

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A.11   Culvert Entrance Loss Coefficients

       Type of Structure and Design of Entrance               Coefficient
       • Pipe. Concrete
           Projecting from fill, socket end (groove-end)                0.2
           Projecting from fill, sq. cut end                            0.5
           Headwall or headwall and wingwalls:
               Socket  end of pipe (groove-end)                       0.2
               Square-edge                                        0.5
           Rounded (radius = D/12)                                 0.2
           Mitered to conform to fill slope                            0.7
           *End-Section conforming to fill slope                       0.5
           Beveled edges, 33.7 ° or 45 ° bevels                      0.2
           Side- or slope-tapered inlet                               0.2
       • Pipe or Pipe-Arch. Corrugated Metal
           Projecting from fill (no headwall)                           0.9
           Headwall or headwall and wingwalls square-edge           0.5
           Mitered to conform to fill slope, paved or unpaved slope     0.7
           *End-Section conforming to fill slope                       0.5
           Beveled edges, 33.7 ° or 45 ° bevels                      0.2
           Side- or slope-tapered inlet                               0.2
       • Box. Reinforced Concrete
           Headwall parallel to embankment (no wingwalls):
               Square-edged on 3 edges                            0.5
               Rounded on 3 edges to radius of D/12 or B/12
                  or beveled edges on 3 sides                       0.2
           Wingwalls at 30 ° to 75 ° to barrel:
               Square-edged at crown                               0.4
               Crown edge rounded to radius of D/12:
               or beveled top edge                                  0.2
           Wingwall at 10 ° to 25 ° to barrel:
               Square-edged at crown                               0.5
           Wingwalls parallel (extension of sides):
               Square-edged at crown                               0.7
               Side- or slope-tapered inlet                           0.2

       *Note: "End Sections conforming to fill slope," made of either metal  or concrete, are the
       sections commonly available  from manufacturers. From limited hydraulic tests they are
       equivalent in operation to a  headwall in  both inlet and outlet control.  Some end sections,
       incorporating a closed taper in their design have a superior hydraulic  performance. These
       latter sections can  be designed using the information given for the beveled inlet.

       Source: Federal Highway Administration (2005). Hydraulic Design of Highway Culverts,
       Publication No.  FHWA-NHI-01-020.
                                          189

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A.12   Standard Elliptical Pipe Sizes
Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Minor Axis (in)
14
^^_ 19
22
24
27
^^_ 29
32
34
38
^^_ 43
48
53
58
^^_ 63
68
72
77
^^_ 82
87
92
97
^^^ 106
116
Major Axis (in)
23
^^— 30
34
38
42
^^— 45
49
53
60
^^— 68
76
83
91
^^— 98
106
113
121
^^^128
136
143
151
^^^166
180
Minor Axis (mm)
356
^^^483
559
610
686
^^_737
813
864
965
1092
1219
1346
1473
1600
1727
1829
1956
2083
2210
2337
2464
2692
2946
Major Axis (mm)
584
^^^762
864
965
1067
1143
1245
1346
1524
1727
1930
2108
2311
2489
2692
2870
3073
3251
3454
3632
3835
4216
4572
Note: The Minor Axis is the maximum width for a vertical ellipse and the full depth for a horizontal
ellipse while the Major Axis is the maximum width for a horizontal ellipse and the full depth for a
vertical ellipse.

Source: Concrete Pipe Design Manual, American Concrete Pipe Association, 2011
(www.concrete-pipe.org').
                                           190

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A.13   Standard Arch Pipe Sizes




Concrete Arch Pipes
Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Corrugated
Code
18
19
20
21
22
23
24
25
26
27
28
29
Rise (in)
11
13.5
15.5
18
22.5
26.625
31.3125
36
40
45
54
62
72
77.5
87.125
96.875
106.5
Steel, 2-2/3 x 1/2"
Rise (in)
13
15
18
20
24
29
33
38
43
47
52
57
Span (in)
18
22
26
28.5
36.25
43.75
51.125
58.5
65
73
88
102
115
122
138
154
168.75
Corrugation
Span (in)
17
21
24
28
35
42
49
57
64
71
77
83
Rise (mm)
279
343
394
457
572
676
795
914
1016
1143
1372
1575
1829
1969
2213
2461
2705

Rise (mm)
330
381
457
508
610
737
838
965
1092
1194
1321
1448
Span (mm)
457
559
660
724
921
1111
1299
1486
1651
1854
2235
2591
2921
3099
3505
3912
4286

Span (mm)
432
533
610
711
889
1067
1245
1448
1626
1803
1956
2108
                                         191

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Corrugated Steel, 3x1" Corrugation
Code
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Rise (in)
31
36
41
46
51
55
59
63
67
71
75
79
83
87
91
Span (in)
40
46
53
60
66
73
81
87
95
103
112
117
128
137
142
Rise (mm)
787
914
1041
1168
1295
1397
1499
1600
1702
1803
1905
2007
2108
2210
2311
Span (mm)
1016
1168
1346
1524
1676
1854
2057
2210
2413
2616
2845
2972
3251
3480
3607
                                       192

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Structural Plate, 18" Corner Radius
Code
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
Rise (in)
55
57
59
61
63
65
67
69
71
73
75
77
79
81
83
85
87
89
91
93
95
97
100
101
103
105
107
109
111
113
115
118
119
121
Span (in)
73
76
81
84
87
92
95
98
103
106
112
114
117
123
128
131
137
139
142
148
150
152
154
161
167
169
171
178
184
186
188
190
197
199
Rise (mm)
1397
1448
1499
1549
1600
1651
1702
1753
1803
1854
1905
1956
2007
2057
2108
2159
2210
2261
2311
2362
2413
2464
2540
2565
2616
2667
2718
2769
2819
2870
2921
2997
3023
3073
Span (mm)
1854
1930
2057
2134
2210
2337
2413
2489
2616
2692
2845
2896
2972
3124
3251
3327
3480
3531
3607
3759
3810
3861
3912
4089
4242
4293
4343
4521
4674
4724
4775
4826
5004
5055
                                         193

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Structural Plate, 31" Corner Radius
  Code
Rise (in)
Span (in)
Rise (mm)
Span (mm)
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
112
114
116
118
120
122
124
126
128
130
132
134
136
138
140
142
144
146
148
150
152
154
156
158
159
162
168
170
173
179
184
187
190
195
198
204
206
209
215
217
223
225
231
234
236
239
245
247
2845
2896
2946
2997
3048
3099
3150
3200
3251
3302
3353
3404
3454
3505
3556
3607
3658
3708
3759
3810
3861
3912
3962
4013
4039
4115
4267
4318
4394
4547
4674
4750
4826
4953
5029
5182
5232
5309
5461
5512
5664
5715
5867
5944
5994
6071
6223
6274
Source: Modern Sewer Design (Fourth Edition), American Iron and Steel Institute, Washington,
DC, 1999.
                                         194

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         APPENDIX B-VISUAL OBJECT PROPERTIES
B.1   Rain Gage Properties
Name
X-Coordinate
Y-Coordinate
Description
Tag
Rain Format
Rain Interval
Snow Catch Factor
Data Source
TIME SERIES
- Series Name
DATA FILE
- File Name
- Station No.
- Rain Units
User-assigned rain gage name.
Horizontal location of the rain gage on the Study Area Map. If left blank
then the rain gage will not appear on the map.
Vertical location of the rain gage on the Study Area Map. If left blank then
the rain gage will not appear on the map.
Click the ellipsis button (or press Enter) to edit an optional description of
the rain gage.
Optional label used to categorize or classify the rain gage.
Format in which the rain data are supplied:
INTENSITY: each rainfall value is an average rate in inches/hour (or
mm/hour) over the recording interval,
VOLUME: each rainfall value is the volume of rain that fell in the recording
interval (in inches or millimeters),
CUMULATIVE: each rainfall value represents the cumulative rainfall that
has occurred since the start of the last series of non-zero values (in inches
or millimeters).
Recording time interval between gage readings in either decimal hours or
hours:minutes format.
Factor that corrects gage readings for snowfall.
Source of rainfall data; either TIMESERIES for user-supplied time series
data or F/LEfor an external data file.

Name of time series with rainfall data if Data Source selection was
TIMESERIES; leave blank otherwise (double-click to edit the series).

Name of external file containing rainfall data (see Section 1 1 .3).
Recording gage station number.
Depth units (IN or MM) for rainfall values in user-prepared files (other
standard file formats have fixed units depending on the format).
                            195

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B.2    Subcatchment Properties
Name
X-Coordinate
^-Coordinate
Description
Tag
Rain Gage
Outlet
Area
Width1
% Slope
% Imperv
N-lmperv
N-Perv
Dstore-lmperv
Dstore-Perv
% Zero-lmperv
Subarea Routing
Percent Routed
Infiltration
LID Controls
User-assigned subcatchment name.
Horizontal location of the subcatchment's centroid on the Study Area Map.
If left blank then the subcatchment will not appear on the map.
Vertical location of the subcatchment's centroid on the Study Area Map. If
left blank then the subcatchment will not appear on the map.
Click the ellipsis button (or press Enter) to edit an optional description of
the subcatchment.
Optional label used to categorize or classify the subcatchment.
Name of the rain gage associated with the subcatchment.
Name of the node or subcatchment which receives the subcatchment's
runoff.
Area of the subcatchment , including any LID controls (acres or hectares).
Characteristic width of the overland flow path for sheet flow runoff (feet or
meters).
Average percent slope of the subcatchment.
Percent of land area (excluding the area used for LID controls) which is
impervious.
Manning's n for overland flow over the impervious portion of the
subcatchment (see Section A.6 for typical values).
Manning's n for overland flow over the pervious portion of the
subcatchment (see Section A.6 for typical values).
Depth of depression storage on the impervious portion of the
subcatchment (inches or millimeters) (see Section A. 5 for typical values).
Depth of depression storage on the pervious portion of the subcatchment
(inches or millimeters) (see Section A. 5 for typical values).
Percent of the impervious area with no depression storage.
Choice of internal routing of runoff between pervious and impervious
areas:
IMPERV: runoff from pervious area flows to impervious area,
PERV: runoff from impervious area flows to pervious area,
OUTLET, runoff from both areas flows directly to outlet.
Percent of runoff routed between subareas.
Click the ellipsis button (or press Enter) to edit infiltration parameters for
the subcatchment.
Click the ellipsis button (or press Enter) to edit the use of low impact
development controls in the subcatchment.
                                        196

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Groundwater
Snow Pack
Land Uses
Initial Buildup
Curb Length
Click the ellipsis button (or press Enter) to edit groundwater flow
parameters for the subcatchment.
Name of snow pack parameter set (if any) assigned to the subcatchment.
Click the ellipsis button (or press Enter) to assign land uses to the
subcatchment. Only needed if pollutant buildup/washoff modeled.
Click the ellipsis button (or press Enter) to specify initial quantities of
pollutant buildup over the subcatchment.
Total length of curbs in the subcatchment (any length units). Used only
when pollutant buildup is normalized to curb length.
1 An initial estimate of the characteristic width is given by the subcatchment area divided by the
average maximum overland flow length. The maximum overland flow length is the length of the
flow path  from the furthest drainage point  of  the  subcatchment before the flow becomes
channelized. Maximum  lengths from several different  possible flow paths  should be averaged.
These paths should reflect slow flow, such as over pervious surfaces, more than rapid flow over
pavement, for example.  Adjustments should be made to the width parameter to produce good fits
to measured runoff hydrographs.
                                          197

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B.3    Junction Properties
Name
X-Coordinate
Y-Coordinate
Description
Tag
Inflows
Treatment
Invert El.
Max. Depth
Initial Depth
Surcharge Depth
Ponded Area
User-assigned junction name.
Horizontal location of the junction on the Study Area Map. If left blank then
the junction will not appear on the map.
Vertical location of the junction on the Study Area Map. If left blank then
the junction will not appear on the map.
Click the ellipsis button (or press Enter) to edit an optional description of
the junction.
Optional label used to categorize or classify the junction.
Click the ellipsis button (or press Enter) to assign external direct, dry
weather or RDM inflows to the junction.
Click the ellipsis button (or press Enter) to edit a set of treatment functions
for pollutants entering the node.
Invert elevation of the junction (feet or meters).
Maximum depth of junction (i.e., from ground surface to invert) (feet or
meters). If zero, then the distance from the invert to the top of the highest
connecting link will be used.
Depth of water at the junction at the start of the simulation (feet or
meters).
Additional depth of water beyond the maximum depth that is allowed
before the junction floods (feet or meters). This parameter can be used to
simulate bolted manhole covers or force main connections.
Area occupied by ponded water atop the junction after flooding occurs (sq.
feet or sq. meters). If the Allow Ponding simulation option is turned on, a
non-zero value of this parameter will allow ponded water to be stored and
subsequently returned to the conveyance system when capacity exists.
                                          198

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B.4     Outfall Properties
Name
X-Coordinate
Y-Coordinate
Description
Tag
Inflows
Treatment
Invert El.
Tide Gate
Route To
Type
Fixed Stage
Tidal Curve Name
Time Series Name
User-assigned outfall name.
Horizontal location of the outfall on the Study Area Map. If left blank then
the outfall will not appear on the map.
Vertical location of the outfall on the Study Area Map. If left blank then the
outfall will not appear on the map.
Click the ellipsis button (or press Enter) to edit an optional description of
the outfall.
Optional label used to categorize or classify the outfall.
Click the ellipsis button (or press Enter) to assign external direct, dry
weather or RDM inflows to the outfall.
Click the ellipsis button (or press Enter) to edit a set of treatment functions
for pollutants entering the node.
Invert elevation of the outfall (feet or meters).
YES - tide gate present to prevent backflow
WO - no tide gate present
Optional name of a subcatchment that receives the outfall's discharge.
Type of outfall boundary condition:
FREE: outfall stage determined by minimum of critical flow depth and
normal flow depth in the connecting conduit
NORMAL: outfall stage based on normal flow depth in connecting conduit
FIXED: outfall stage set to a fixed value
TIDAL: outfall stage given by a table of tide elevation versus time of day
TIMESERIES: outfall stage supplied from a time series of elevations.
Water elevation for a FIXED type of outfall (feet or meters).
Name of the Tidal Curve relating water elevation to hour of the day for a
TIDAL outfall (double-click to edit the curve).
Name of time series containing time history of outfall elevations for a
TIMESERIES outfall (double-click to edit the series).
                                             199

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B.5    Flow Divider Properties
Name
X-Coordinate
Y-Coordinate
Description
Tag
Inflows
Treatment
Invert El.
Max. Depth
Initial Depth
Surcharge Depth
Ponded Area
Diverted Link
Type
User-assigned divider name.
Horizontal location of the divider on the Study Area Map. If left blank then
the divider will not appear on the map.
Vertical location of the divider on the Study Area Map. If left blank then the
divider will not appear on the map.
Click the ellipsis button (or press Enter) to edit an optional description of
the divider.
Optional label used to categorize or classify the divider.
Click the ellipsis button (or press Enter) to assign external direct, dry
weather or RDM inflows to the divider.
Click the ellipsis button (or press Enter) to edit a set of treatment functions
for pollutants entering the node.
Invert elevation of the divider (feet or meters).
Maximum depth of divider (i.e., from ground surface to invert) (feet or
meters). See description for Junctions.
Depth of water at the divider at the start of the simulation (feet or meters).
Additional depth of water beyond the maximum depth that is allowed
before the divider floods (feet or meters).
Area occupied by ponded water atop the junction after flooding occurs (sq.
feet or sq. meters). See description for Junctions.
Name of link which receives the diverted flow.
Type of flow divider. Choices are:
CUTOFF (diverts all inflow above a defined cutoff value),
OVERFLOW (diverts all inflow above the flow capacity of the non-diverted
link),
TABULAR (uses a Diversion Curve to express diverted flow as a function
of the total inflow),
WEIR (uses a weir equation to compute diverted flow).
CUTOFF DIVIDER
- Cutoff Flow
Cutoff flow value used for a CUTOFF divider (flow units).
TABULAR DIVIDER
- Curve Name
Name of Diversion Curve used with a TABULAR divider (double-click to
edit the curve).
                                           200

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WEIR DIVIDER
- Min. Flow
- Max. Depth
- Coefficient
Minimum flow at which diversion begins for a WEIR divider (flow units).
Vertical height of WEIR opening (feet or meters)
Product of WEIR's discharge coefficient and its length. Weir coefficients
are typically in the range of 2.65 to 3.10 per foot, for flows in CFS.
Note:  Flow dividers are operational only for Steady Flow and Kinematic Wave flow routing. For
       Dynamic Wave flow routing they behave as Junction nodes.
                                         201

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B.6    Storage Unit Properties
Name
X-Coordinate
Y-Coordinate
Description
Tag
Inflows
Treatment
Invert El.
Max. Depth
Initial Depth
Evap. Factor
Seepage Loss
Storage Curve
FUNCTIONAL
Coeff.
Exponent
Constant
User-assigned storage unit name.
Horizontal location of the storage unit on the Study Area Map. If left blank
then the storage unit will not appear on the map.
Vertical location of the storage unit on the Study Area Map. If left blank
then the storage unit will not appear on the map.
Click the ellipsis button (or press Enter) to edit an optional description of
the storage unit.
Optional label used to categorize or classify the storage unit.
Click the ellipsis button (or press Enter) to assign external direct, dry
weather or RDM inflows to the storage unit.
Click the ellipsis button (or press Enter) to edit a set of treatment functions
for pollutants within the storage unit.
Elevation of the bottom of the storage unit (feet or meters).
Maximum depth of the storage unit (feet or meters).
Initial depth of water in the storage unit at the start of the simulation (feet
or meters).
The fraction of the potential evaporation from the storage unit's water
surface that is actually realized.
Click the ellipsis button (or press Enter) to specify optional soil properties
that determine seepage loss through the bottom and sloped sides of the
storage unit.
Method of describing how the surface area of the storage unit varies with
water depth:
FUNCTIONAL uses the function
Area = A*(Depth)B + C
to describe how surface area varies with depth;
TABULAR uses a tabulated area versus depth curve.
In either case, depth is measured in feet (or meters) above the bottom and
surface area in sq. feet (or sq. meters).

A-value in the functional relationship between surface area and storage
depth.
B-value in the functional relationship between surface area and storage
depth.
C-value in the functional relationship between surface area and storage
depth.
                                           202

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TABULAR
Curve Name

Name of the Storage Curve containing the relationship between surface
area and storage depth (double-click to edit the curve). The curve will be
extrapolated outwards to meet the unit's Max. Depth if need be.
203

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B.7    Conduit Properties
Name
Inlet Node
Outlet Node
Description
Tag
Shape
Max. Depth
Length
Roughness
Inlet Offset
Outlet Offset
Initial Flow
Maximum Flow
Entry Loss Coeff.
Exit Loss Coeff.
Avg. Loss Coeff.
Flap Gate
Culvert Code
User-assigned conduit name.
Name of node on the inlet end of the conduit (which is normally the end at
higher elevation).
Name of node on the outlet end of the conduit (which is normally the end
at lower elevation).
Click the ellipsis button (or press Enter) to edit an optional description of
the conduit.
Optional label used to categorize or classify the conduit.
Click the ellipsis button (or press Enter) to edit the geometric properties of
the conduit's cross section.
Maximum depth of the conduit's cross section (feet or meters).
Conduit length (feet or meters).
Manning's roughness coefficient (see Section A.7 for closed conduit
values or Section A. 8 for open channel values).
Depth or elevation of the conduit invert above the node invert at the
upstream end of the conduit (feet or meters). See note below.
Depth or elevation of the conduit invert above the node invert at the
downstream end of the conduit (feet or meters). See note below.
Initial flow in the conduit (flow units).
Maximum flow allowed in the conduit (flow units) - use 0 or leave blank if
not applicable.
Head loss coefficient associated with energy losses at the entrance of the
conduit. For culverts, refer to Table A1 1 .
Head loss coefficient associated with energy losses at the exit of the
conduit. For culverts, use a value of 1 .0
Head loss coefficient associated with energy losses along the length of
the conduit.
YES if a flap gate exists that prevents backflow through the conduit, or WO
if no flap gate exists.
Code number of inlet geometry if conduit is a culvert - leave blank
otherwise. Culvert code numbers are listed in Table A10.
                                          204

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NOTE:  Conduits  and flow regulators (orifices, weirs,
and  outlets) can  be offset some distance  above the
invert of their connecting end nodes. There are two
different conventions  available  for specifying  the
location of these  offsets. The Depth convention uses
the offset distance from the  node's invert (distance
between © and  © in the figure on the  right).  The
Elevation convention uses the absolute elevation of the
offset location (the elevation of point ©  in the figure).
The  choice of convention can be made  on  the Status
Bar  of  SWMM's  main window  or  on the  Node/Link
Properties page of the Project Defaults dialog.
B.8     Pump Properties
Name
Inlet Node
Outlet Node
Description
Tag
Pump Curve
Initial Status
Startup Depth
Shutoff Depth
User-assigned pump name.
Name of node on the inlet side of the pump.
Name of node on the outlet side of the pump.
Click the ellipsis button (or press Enter) to edit an optional description of
the pump.
Optional label used to categorize or classify the pump.
Name of the Pump Curve which contains the pump's operating data
(double-click to edit the curve). Enter* for an Ideal pump.
Status of the pump (ON or OFF) at the start of the simulation.
Depth at inlet node when pump turns on (feet or meters). Enter 0 if not
applicable.
Depth at inlet node when pump shuts off (feet or meters). Enter 0 if not
applicable.
                                           205

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B.9     Orifice Properties
Name
Inlet Node
Outlet Node
Description
Tag
Type
Shape
Height
Width
Inlet Offset
Discharge Coeff.
Flap Gate
Time to Open /
Close
User-assigned orifice name.
Name of node on the inlet side of the orifice.
Name of node on the outlet side of the orifice.
Click the ellipsis button (or press Enter) to edit an optional description of
the orifice.
Optional label used to categorize or classify the orifice.
Type of orifice (SIDE or BOTTOM).
Orifice shape (CIRCULAR or RECT_ CLOSED).
Height of orifice opening when fully open (feet or meters). Corresponds to
the diameter of a circular orifice or the height of a rectangular orifice.
Width of rectangular orifice when fully opened (feet or meters).
Depth or elevation of bottom of orifice above invert of inlet node (feet or
meters - see note below table of Conduit Properties).
Discharge coefficient (unitless). A typical value is 0.65.
YES if a flap gate exists which prevents backflow through the orifice, or
WO if no flap gate exists.
The time it takes to open a closed (or close an open) gated orifice in
decimal hours. Use 0 or leave blank if timed openings/closings do not
apply. Use Control Rules to adjust gate position.
                                             206

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B.10   Weir Properties
Name
Inlet Node
Outlet Node
Description
Tag
Type
Height
Length
Side Slope
Inlet Offset
Discharge Coeff.1
Flap Gate
End Coeff.
End Contractions
Can Surcharge
ROADWAY WEIR
Road Width
Road Surface
User-assigned weir name.
Name of node on inlet side of weir.
Name of node on outlet side of weir.
Click the ellipsis button (or press Enter) to edit an optional description of
the weir.
Optional label used to categorize or classify the weir.
Weir type: TRANSVERSE, SIDEFLOW, V-NOTCH, TRAPEZOIDAL or
ROADWAY.
Vertical height of weir opening (feet or meters).
Horizontal length of weir opening (feet or meters).
Slope (width-to-height) of side walls for a V-NOTCH or TRAPEZOIDAL
weir.
Depth or elevation of bottom of weir opening from invert of inlet node
(feet or meters - see note below table of Conduit Properties).
Discharge coefficient for flow through the central portion of the weir (for
flow in CFS when using US units or CMS when using SI units).
YES if the weir has a flap gate that prevents backflow, WO otherwise..
Discharge coefficient for flow through the triangular ends of a
TRAPEZOIDALwe\r. See the recommended values for V-notch weirs.
Number of end contractions for a TRANSVERSE or TRAPEZOIDAL
weir whose length is shorter than the channel it is placed in. Values will
be either 0, 1, or 2 depending if no ends, one end, or both ends are
beveled in from the side walls.
YES if the weir can surcharge (have an upstream water level higher
than the height of the opening) or WO if it cannot.

Width of roadway and shoulders (feet or meters)
Type of road surface: PAVED or GRAVEL.
1  Typical values are: 3.33 US (1.84 SI) for sharp crested transverse weirs, 2.5 - 3.3 US (1.38 -
1.83 SI) for broad crested rectangular weirs, 2.4 - 2.8 US (1.35 - 1.55 SI) for V-notch (triangular)
weirs. Discharge over Roadway weirs with a non-zero road width is  computed using the FHWA
HDS-5 method.
                                           207

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B.11   Outlet Properties
Name
Inlet Node
Outlet Node
Description
Tag
Inlet Offset
Flap Gate
Rating Curve
FUNCTIONAL
- Coefficient
- Exponent
TABULAR
- Curve Name
User-assigned outlet name.
Name of node on inflow side of outlet.
Name of node on discharge side of outlet.
Click the ellipsis button (or press Enter) to edit an optional description of
the outlet.
Optional label used to categorize or classify the outlet.
Depth or elevation of outlet above inlet node invert (feet or meters - see
note below table of Conduit Properties).
YES if a flap gate exists which prevents backflow through the outlet, or
WO if no flap gate exists.
Method of defining flow (Q) as a function of depth or head (y) across the
outlet.
FUNCTIONAL/DEPTH uses a power function (Q = AyB) to describe this
relation where y is the depth of water above the outlet's opening at the
inlet node.
FUNCTIONAL/HEAD uses the same power function except that y is the
difference in head across the outlet's nodes.
TABULAR/DEPTH uses a tabulated curve of flow versus depth of water
above the outlet's opening at the inlet node.
TABULAR/HEAD uses a tabulated curve of flow versus difference in head
across the outlet's nodes.

Coefficient (A) for the functional relationship between depth or head and
flow rate.
Exponent (B) used for the functional relationship between depth or head
and flow rate.

Name of Rating Curve containing the relationship between depth or head
and flow rate (double-click to edit the curve).
                                            208

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B.12   Map Label Properties
Text
X-Coordinate
Y-Coordinate
Anchor Node
Font
Text of label.
Horizontal location of the upper-left corner of the label on the Study Area
Map.
Vertical location of the upper-left corner of the label on the Study Area
Map.
Name of node (or subcatchment) that anchors the label's position when
the map is zoomed in (i.e., the pixel distance between the node and the
label remains constant). Leave blank if anchoring is not used.
Click the ellipsis button (or press Enter) to modify the font used to draw
the label.
                                         209

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           APPENDIX C - SPECIALIZED PROPERTY EDITORS
C.1    Aquifer Editor

The Aquifer Editor is invoked whenever a new aquifer object is created or an existing aquifer
object is selected for editing. It contains the following data fields:
Aquifer Editor (o)
Property
Aquifer Name
Porosity
Wilting Point
Field Capacity
Conductivity
Conductivity Slope
Tension Slope
Upper Evap. Fraction
Lower Evap. Depth
Lower GW Loss Rate
Bottom Elevation
Water Table Elevation
Unsat. Zone Moisture
Upper Evap. Pattern
Value
Al
0.5
0.15
0.30
5.0
10.0
15.0
0.35
14.0
0.002
0.0
10.0
0.30

User-assigned aquifer name
OK Cancel Help

                                                Name
                                                User-assigned aquifer name.

                                                Porosity
                                                Volume of voids / total soil volume
                                                (volumetric fraction).

                                                Wilting Point
                                                Soil moisture content at which plants
                                                cannot survive (volumetric fraction).

                                                Field Capacity
                                                Soil moisture content after all free
                                                water has drained off (volumetric
                                                fraction).

                                                Conductivity
                                                Soil's saturated hydraulic conductivity
                                                (in/hror mm/hr).

                                                Conductivity Slope
                                                Average slope of log(conductivity)
                                                versus soil moisture deficit (porosity
                                                minus moisture content)  curve
                                                (unitless).
Tension Slope
Average slope of soil tension versus soil moisture content curve (inches or mm).

Upper Evaporation Fraction
Fraction of total evaporation available for evapotranspiration in the upper unsaturated zone.

Lower Evaporation Depth
Maximum depth below the surface at which evapotranspiration from the lower saturated zone can
still occur (ft or m).
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Lower Groundwater Loss Rate
Rate of percolation to deep groundwater when the water table reaches the ground surface (in/hr
or mm/hr).

Bottom Elevation
Elevation of the bottom of the aquifer (ft or m).

Water Table Elevation
Elevation of the water table in the aquifer at the start of the simulation (ft or m).

Unsaturated Zone Moisture
Moisture content of the unsaturated upper zone of the aquifer at the  start  of the simulation
(volumetric fraction) (cannot exceed soil  porosity).

Upper Evaporation Pattern
Name  of the monthly time pattern of  adjustments applied to  the upper evaporation  fraction
(optional - leave blank if not applicable).
                                          211

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C.2     Climatology Editor

The Climatology Editor is used to enter values for various climate-related variables required by
certain  SWMM simulations.  The  dialog is  divided  into six tabbed pages,  where each page
provides a separate editor for a specific category of climate data.


Temperature Page
  Climatology Editor
       Snow Melt
       Temperature
Areal Depletion
   Evaporation
Adjustments
Wind Speed
     Source of Temperature Data:


        « No Data


          Time Series
          External Climate File
           tart Reading File at
The  Temperature page of the Climatology  Editor dialog is  used  to  specify the  source of
temperature data used  for snowmelt computations. It is also used to select a climate file as a
possible source for evaporation rates. There are three choices available:

No Data:       Select this choice  if snowmelt is not being simulated  and evaporation rates are
               not based on data  in a climate file.

Time Series:   Select this choice if the variation in temperature over the simulation period will be
               described by one of the project's time series. Also, enter (or select) the name of
                                            212

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               the time series. Click the
               the selected time series.
                             button to make the Time Series Editor appear for
External
Climate File:
Select this choice if min/max daily temperatures will be read  from an external
                                                                          M.
climate file (see Section 11.4). Also enter the name of the file (or click the  «
button to search for the file). If  you want to start reading the climate file at a
particular date in time that is different than  the start date  of the simulation (as
specified in the Simulation  Options), check off the "Start Reading File at" box and
enter a starting date (month/day/year)  in the date entry field next to it. Use this
choice  if  you  want  daily evaporation  rates  to  be estimated  from   daily
temperatures or be read directly from the file.
Evaporation Page
 Climatology Editor
       Snow Melt
       Temperature
          Areal Depletion
            Evaporation
Adjustments
Wind Speed
     Source of Evaporation Rates     Constant Value
     Daily Evaporation (in/day)
                                  Constant Value
                   Time Series
                   Climate File
                   Monthly Averages
                   Temperatures
      Monthly Soil Recovery
      Pattern (Optional)
      ^\ Evaporate Only During Dry Periods
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The  Evaporation page of the Climatology Editor dialog is used to  supply evaporation rates, in
inches/day (or mm/day), for a study area. There are five  choices for specifying these rates that
are selected from the Source of Evaporation Rates combo box:

Constant Value:
Use  this choice if evaporation remains  constant  over time. Enter the value in  the edit box
provided.

Time Series:
Select this choice if evaporation rates will be specified  in a time series. Enter or select the name
of the time series in the dropdown combo box provided. Click the  ^ button to bring up the Time
Series  editor for the  selected series. Note that for each  date  specified in the time series,  the
evaporation  rate remains constant at the value supplied for that  date  until the next date in  the
series is reached (i.e., interpolation is not used on the series).

Directly From Climate File:
This  choice indicates that daily evaporation rates will be read from the same  climate file that was
specified for temperature. Enter values for monthly pan  coefficients in the data grid provided.

Monthly Averages:
Use  this choice to supply an average rate for each month of the  year. Enter the value for each
month in the data grid provided. Note that rates  remain  constant within each month.

Computed from Temperatures:
The  Hargreaves method will be  used to compute daily  evaporation rates from  the daily air
temperature record contained in the external climate file specified on the Temperature page of
the dialog. This method also uses  the site's latitude, which can be  entered on the Snowmelt page
of the dialog even if snow melt is not being simulated.

Evaporate Only During Dry Periods:
Select this option if evaporation can only occur during periods with no precipitation.

In addition this page allows the user to specify an optional Monthly Soil Recovery  Pattern. This
is a  time pattern whose factors adjust the rate at which infiltration capacity  is recovered during
periods with no precipitation. It applies to all subcatchments for any choice of infiltration method.
For example, if the normal  infiltration recovery rate was 1% during  a specific time  period and a
pattern factor of 0.8 applied to this period, then the  actual  recovery rate would be 0.8%. The Soil
Recovery Pattern allows one to account for seasonal soil drying  rates. In principle, the variation in
pattern factors should mirror the variation  in evaporation rates  but might be  influenced by other
factors such as seasonal groundwater levels. The ^  button  is used to launch the  Time Pattern
Editor for the selected pattern.
                                           214

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Wind Speed Page
 Climatology Editor
       Snow Melt
        Areal Depletion
       Temperature     |     Evaporation
                     Adjustments
                             Wind Speed
        •*' Use Climate File Data (see Temperature Page)
          Use Monthly Averages
        Monthly Wind Speed (mph)
        | Jan
        EM
Feb
Mar     Apr     May    Jun
0.0
0.0
0.0
0.0      0.0
         Jul
Aug     Sep    | Oct
               Nov     Dec
                0.0
        0.0
        0.0
        0.0     0.0
The Wind Speed page of the Climatology Editor dialog is used to provide average monthly wind
speeds. These are  used when computing snowmelt rates under rainfall conditions. Melt rates
increase with  increasing wind speed.  Units  of wind  speed  are  miles/hour for US  units and
km/hour for metric units. There  are two choices for specifying wind speeds:
Climate File Data:
Monthly Averages:
      Wind speeds will be read from the same climate file that was specified
      for temperature.

      Wind speed is specified  as  an average value that remains constant in
      each  month of the year.  Enter a value for each month in the data grid
      provided. The default values  are all zero.
                                           215

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Snowmelt Page
  Climatology Editor
       Temperature          Evaporation
       Snow Melt
                        Areal Depletion
Wind Speed
Adjustments
           Dividing Temperature
           Between Snow and Rain      34
           (degrees F)

           ATI Weight (fraction)        0.5
           Negative Melt Ratio         0,6
           (fraction)
           Elevation above MSL         0.0
           (feet)

           Latitude (degrees)           50.0
           Longitude Correction        0,0
           (+/- minutes)
The Snowmelt page of the Climatology Editor dialog is used to supply values for the following
parameters related to snow melt calculations:

Dividing Temperature Between Snow and Rain
Enter the temperature below which precipitation falls as snow instead of rain. Use degrees F for
US units or degrees C for metric units.

ATI (Antecedent Temperature Index) Weight
This parameter reflects the degree to which  heat transfer within a snow pack during non-melt
periods is affected by prior air temperatures. Smaller values reflect a thicker surface layer of snow
which results in reduced rates of heat transfer. Values must be between 0 and 1, and the default
is 0.5.

Negative Melt Ratio
This is the ratio of the heat transfer coefficient of a snow pack during non-melt conditions to the
coefficient during melt conditions. It must be a  number between 0 and 1. The default value is 0.6.
                                           216

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Elevation Above MSL
Enter the average elevation above mean sea level for the study area, in feet or meters. This value
is used to provide a more accurate estimate of atmospheric pressure. The default is 0.0, which
results in a pressure of 29.9  inches Hg. The  effect of wind on snow melt  rates during rainfall
periods is greater at higher pressures, which occur at lower elevations.

Latitude
Enter the latitude of the study area in degrees North. This number is used when computing the
hours of sunrise and sunset, which in turn are used to extend min/max daily temperatures into
continuous values.  It is  also used to compute daily evaporation  rates from daily temperatures.
The default is 50 degrees North.

Longitude Correction
This  is a correction, in  minutes of time, between true solar time and the standard clock time. It
depends on a location's longitude (6) and the standard meridian of its time zone (SM) through the
expression 4(6-SM).  This correction is  used to  adjust the hours of  sunrise and  sunset when
extending daily min/max temperatures into  continuous values. The default value is 0.
                                          217

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Areal Depletion Page
  Climatology Editor
Temperature | Evaporation Wind Speed
Snow Melt
Areal Depletion
Adjustments
Fraction of Area Covered by Snow

Depth Ratio
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
OS

Impervious
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1JD
No Depletion
Natural Area
Pervious
1.0
1JO
1JO
IJQ
1JO
in
1JO
in
1JO
in
No Depletion
Natural Area


                 OK
The Areal Depletion page of the Climatology Editor Dialog is used to specify points on the Areal
Depletion Curves for both impervious and pervious surfaces within  a project's study area. These
curves define the relation between the area that remains snow covered and snow pack depth.
Each curve is defined by 10 equal increments of relative depth ratio between 0 and 0.9. (Relative
depth ratio is the ratio of an area's current snow depth to the depth at which there is 100% areal
coverage).

Enter values in the data grid provided for the fraction of each area that remains snow covered at
each specified  relative depth  ratio. Valid  numbers must be between  0 and  1, and be increasing
with increasing  depth ratio.

Clicking the Natural Area button fills the grid with values that are typical of natural areas. Clicking
the No Depletion button will fill the grid with all 1's, indicating that no  areal depletion occurs. This
is the default for new projects.
                                           218

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Adjustments Page
  Climatology Editor
Temperature | Evaporation | Wind Speed
Snow Melt Areal Depletion Adjustments
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Temp
Evap























Rain












Cond












Temp temperature adjustment (+- deg F or deg C)
Evap evaporation adjustment (+- in/day or mm/day)
Rain rainfall multiplier
Cond soil conductivity multiplier

Clear All

The  Adjustments page  of the Climatology Editor Dialog is used to supply a set of monthly
adjustments applied to the temperature, evaporation  rate, rainfall, and soil hydraulic conductivity
that SWMM uses at each time step of a simulation:
    •  The monthly Temperature adjustment (plus or minus  in either degrees F or C) is added to
       the temperature  value that SWMM would otherwise use in a specific month of the year.
    •  The monthly Evaporation adjustment (plus or minus in either in/day or mm/day) is added
       to the evaporation rate value that SWMM would otherwise use in a specific month of the
       year.
    •  The monthly Rainfall adjustment  is a multiplier applied to the  precipitation  value  that
       SWMM would otherwise use in a specific month of the year.
    •  The monthly  Conductivity adjustment  is a multiplier  applied  to  the soil  hydraulic
       conductivity used  compute rainfall infiltration, groundwater percolation, and  exfiltration
       from channels and storage units.
The same adjustment is  applied for each time period within a  given month and is repeated for that
month in  each subsequent year being simulated. Leaving a monthly adjustment blank means that
there is no adjustment made  in that month.
                                           219

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C.3
Control Rules Editor
  Control Rules Editor
  RULE FUKF1A
  IF NODE SU1 DEPTH  >=  4
  THEN PUMP FUKF1  status  = OH
  PRIORITY 1

  RULE FUMF1B
  IF NODE SU1 DEPTH  < 1
  THEN FUMF FUKF1  status  = OFF
  PRIORITY 1

               OK
  Click Help to review the format of Control Rule statements.
The Control Rules Editor is invoked whenever a new control rule is created or an existing rule is
selected for editing. The editor contains a memo field where the entire collection of control rules is
displayed and can be edited.

Control Rule Format
Each control rule  is a series of statements of the form:

RULE   rulelD
IF
AND
OR
AND
Etc.
condition_l
condition  2
condition  3
condition  4
THEN
AND
Etc.
ELSE
AND
Etc.
action_l
action_2

action_3
action 4
PRIORITY  value

where  keywords are shown  in boldface  and ruleio is an ID label  assigned  to the rule,
condition n is a Condition Clause, action n  is an Action Clause, and value is a priority
                                         220

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value (e.g., a number from 1 to  5). The formats used for Condition  and Action clauses are
discussed below.

Only the  RULE, IF and THEN portions of a rule are required; the ELSE and PRIORITY portions
are optional.

Blank lines between clauses are permitted and any text to the right of a semicolon is considered a
comment.

When mixing AND and OR clauses,  the OR operator has higher precedence than AND, i.e.,
   IF A or B and C
is equivalent to
   IF (A  or B)  and  C.
If the interpretation was meant to be
   IF A or (B and C)
then this can be expressed using two rules as in
   IF A THEN  . . .
   IF B and C THEN  ...

The PRIORITY value is used to determine which rule applies when two or more rules require that
conflicting actions be taken on a link. A conflicting rule with a higher priority value has precedence
over  one  with a  lower value (e.g.,  PRIORITY 5 outranks PRIORITY 1). A rule without a priority
value always has a lower priority than one with a value. For two rules with the same priority value,
the rule that appears first is given the higher priority.


Condition  Clauses

A Condition Clause of a control rule has the following formats:

object  id attribute relation value
 object  id attribute relation  object id attribute

where:
object       =   a category of object
id            =   the object's ID  label
attribute   =   an attribute or  property of the object
relation     =   a relational operator (=, <>, <, <=, >, >=)
value        =   an attribute value
Some examples of condition clauses are:

NODE  N23   DEPTH  >   10
NODE  N23   DEPTH  >   NODE  N25  DEPTH
PUMP  P45   STATUS =   OFF
SIMULATION CLOCKTIME  = 22:45:00
                                         221

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The objects and attributes that can appear in a condition clause are as follows:
Object
NODE
LINK
CONDUIT
PUMP
ORIFICE
WEIR
OUTLET
SIMULATION
SIMULATION
Attributes
DEPTH
HEAD
VOLUME
INFLOW
FLOW
DEPTH
TIMEOPEN
TIMECLOSED
STATUS
TIMEOPEN
TIMECLOSED
STATUS
SETTING
FLOW
TIMEOPEN
TIMECLOSED
SETTING
TIMEOPEN
TIMECLOSED
SETTING
TIMEOPEN
TIMECLOSED
SETTING
TIMEOPEN
TIMECLOSED
TIME
DATE
MONTH
DAY
CLOCKTIME
Value
numerical value
numerical value
numerical value
numerical value
numerical value
numerical value
decimal hours or hr:min
decimal hours or hr:min
OPEN or CLOSED
decimal hours or hr:min
decimal hours or hr:min
ON or OFF
pump curve multiplier
numerical value
decimal hours or hr:min
decimal hours or hr:min
fraction open
decimal hours or hr:min
decimal hours or hr:min
fraction open
decimal hours or hr:min
decimal hours or hr:min
rating curve multiplier
decimal hours or hr:min
decimal hours or hr:min
elapsed time in decimal hours or
hr:min:sec
month/day/year
month of year (January = 1)
day of week (Sunday = 1)
time of day in hr:min:sec
TIMEOPEN is the duration a link has been in an OPEN or ON state or have its SETTING be greater
than zero; TIMECLOSED is the duration it has remained in a CLOSED or OFF state or have its
SETTING be zero.
                                         222

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Action Clauses

An Action Clause of a control rule can have one of the following formats:

PUMP id  STATUS = ON/OFF
PUMP/ORIFICE/WEIR/OUTLET id  SETTING = value

where the meaning of SETTING depends on the object being controlled:
    •   for Pumps it is a multiplier applied to the flow computed from the pump curve,
    •   for Orifices it is the fractional amount that the orifice is fully open,
    •   for Weirs it is the fractional amount of the original  freeboard that exists (i.e., weir control
       is accomplished by moving the crest height up or down),
    •   for Outlets it is a multiplier applied to the flow computed from the outlet's rating curve.

Some examples of action clauses are:
PUMP P67  STATUS = OFF
ORIFICE  0212  SETTING =0.5


Modulated Controls

Modulated controls are control rules that provide  for a continuous degree of control applied to a
pump or flow regulator as determined  by the value of some controller variable, such  as water
depth at a  node, or by time. The functional relation between the control setting and the controller
variable can be specified  by using a Control Curve, a Time Series, or a PID Controller. Some
examples of modulated control rules are:

RULE MCI
IF  NODE N2 DEPTH >=  0
THEN WEIR W25  SETTING = CURVE  C25

RULE MC2
IF  SIMULATION  TIME  >  0
THEN PUMP P12  SETTING = TIMESERIES  TS101

RULE MC3
IF  LINK  L33 FLOW <>  1.6
THEN ORIFICE  012 SETTING =  PID  0.1  0.0  0.0

Note how a modified form of the action clause is used to specify the name of the control curve,
time series or PID parameter set that defines the degree of control. A PID parameter set contains
three values - a proportional gain coefficient, an  integral time (in minutes), and a derivative time
(in minutes). Also, by convention the controller variable  used in a Control Curve or PID Controller
will  always be the object and attribute named in the  last condition  clause of the rule. As an
example, in  rule  MC1  above Curve  C25 would  define  how the fractional setting  at Weir W25
                                          223

-------
varied with the water depth at Node N2. In rule MC3, the  PID controller adjusts the opening of
Orifice O12 to maintain a flow of 1.6 in Link L33.
PID Controllers

A PID (Proportional-lntegral-Derivative) Controller is a generic closed-loop  control scheme that
tries to maintain  a desired set-point on some process  variable by computing and applying a
corrective action that adjusts the process accordingly. In the context of a hydraulic conveyance
system a PID controller might be used to adjust the opening on a gated orifice to maintain a
target flow rate in a specific conduit or to adjust a variable speed pump to maintain a desired
depth in a storage unit. The classical PID controller has the form:
    m(t) = K.
                                         dt
where m(t)  = controller output,  Kp = proportional coefficient (gain), 7, = integral time,  Td =
derivative time, eft) = error (difference between setpoint and  observed variable value), and  t =
time. The performance of a PID controller is determined by the  values assigned to the coefficients
Kp, Ti, and Td.

The controller output m(t)  has the same meaning as a link setting used in a rule's Action Clause
while  dt is the current flow routing time step in minutes.  Because link settings are relative values
(with respect to either a pump's standard operating curve or to  the full opening height of an orifice
or weir) the error eft) used by the controller is also a relative value. It is defined as the difference
between the  control variable setpoint x* and its value at time t, xft),  normalized to the setpoint
va\ue:e(t) = (x*-x(t))/x*.

Note that for direct action  control, where an increase in the link setting  causes an increase in  the
controlled variable, the sign  of  Kp must be positive. For reverse  action control, where  the
controlled variable decreases as the link setting increases, the sign of  Kp must be negative. The
user must recognize whether the control is direct or reverse action and  use the proper sign on Kd
accordingly. For example, adjusting an orifice opening to maintain a desired downstream flow is
direct action. Adjusting it  to maintain an  upstream water level is reverse action. Controlling a
pump to maintain a fixed wet well water level would be reverse action while using it to maintain a
fixed downstream flow is direct action.
                                            224

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C.4     Cross-Section Editor
 Cross-Section Editor
Rectangular       Trapezoidal
                                      Triangular
        Parabolic
                        Power
                                       Irregular
        Circular
                       Force Main
                                     Filled Circular
                                                       Standard circular pipe.
                                                       Barrels          Dimensions
                                                       i      ~H    ^i
                                                Max. Depth
                                                2
                                                OK
The Cross-Section Editor dialog is used to specify the shape and dimensions of a conduit's cross-
section. When a shape is selected from the image list an appropriate set of edit fields appears for
describing the dimensions of that shape.  Length dimensions are in units of feet for US units and
meters for SI units. Slope values represent ratios of horizontal to vertical  distance. The Barrels
field specifies how many identical parallel  conduits exist between its end nodes.

The Force Main shape option is a circular conduit that uses either the Hazen-Williams or Darcy-
Weisbach formulas to compute friction losses  for pressurized flow during Dynamic  Wave flow
routing. In this case the appropriate C-factor (for Hazen-Williams) or roughness height (for Darcy-
Weisbach) is supplied as a cross-section property. The choice of friction loss equation  is made on
the Dynamic Wave Simulation Options dialog. Note that a conduit does not  have to be  assigned a
Force  Main shape for it to pressurize. Any  of the  other  closed  cross-section shapes can
potentially pressurize  and thus  function as  force mains using the Manning equation to compute
friction losses.

If a Custom shaped section  is chosen, a  drop-down edit box will appear where you can enter or
select the name of a  Shape Curve that will be  used to define the geometry of the section. This
curve specifies how the width of the cross-section varies with height, where both width and height
are scaled relative to the section's maximum depth. This allows the same shape curve to be used
for conduits of differing sizes. Clicking the Edit button  &  next to the shape curve box will bring
up the Curve Editor where the shape curve's coordinates can be edited.

If an Irregular shaped  section is chosen, a drop-down edit box will appear where you can enter or
select the name of a Transect  object that  describes the cross-section's geometry. Clicking the
Edit button &  next to the edit  box will bring  up the Transect Editor from which you can  edit the
transect data.
                                           225

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C.5
Curve Editor
Pu
mp C
Curve
PUMF
Descri
jrve Editor
Name
_CURVE1
Dtion
Pump Type
TYPE4
H

i
2
3
4
5
6
7
8
9
10
11
Depth
m
Flow
(CFSJ
0 I 0.45
4
4.75








0.45
09








>
T
View...

Load...

Save...

OK

Cancel

Help

The Curve Editor dialog is invoked whenever a new curve object is created or an existing curve
object  is selected  for editing. The  editor adapts itself to the category of  curve being  edited
(Storage, Tidal, Diversion, Pump, or Rating). To use the Curve Editor:
    •    Enter values for the following data entry fields:
        Name             Name of the curve.
        Type              (Pump Curves Only). Choice of pump curve type as described  in
                          Section 3.2
        Description        Optional comment or description of what the curve represents. Click
                          the & button to launch a multi-line comment editor if more than one
                          line is needed.
        Data Grid          The curve's X,Y data.
    •    Click the View button to see a graphical plot of the curve drawn in a separate window.
    •    If  additional rows are  needed in the Data Grid, simply press the Enter key when in the
        last row.
    •    Right-clicking over  the Data Grid will make a  popup  Edit menu appear.  It  contains
        commands to cut, copy, insert,  and paste selected cells in  the grid as well as options  to
        insert or delete a row.
You can also click the Load button to load in a curve that was previously saved to file  or click the
Save button to save the current curve's data to a file.
                                           226

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C.6
Groundwater Flow Editor
 Groundwater Flow Editor
  Property
 Aquifer Name
 Receiving Node
 Surface Elevation

 Al Coefficient

 Bl Exponent

 A2 Coefficient

 B2 Exponent

 A3 Coefficient
 Surface Water Depth
 Threshold Water Table Elev.

 Aquifer Bottom Elevation

 Initial Water Table Elev.

 Unsat, Zone Moisture
 Custom Lateral Flow Equation

 Custom Deep Flow Equation
                     Value
                     0,1
                     No
                     No
  Name of Aquifer object that lies below
  subcatchment. Leave blank for no groundwater.
                                    The standard equation for lateral groundwater flow is:
                                       QL = Al*(Hgw-Hcb)ABl
                                           -A2*(Hsw-Hcb)AB2
                                           + A3*Hgw*Hsw
                                    where QL has units of cfs/ac (or cms/ha].
                                    The standard equation for deep groundwater flow is:
                                       QD = LGLR*Hgw/Hgs
                                    where LGLR is the aquifer lower GW loss rate [in/hr or
                                    mm/hr),
OK

Cancel

Help
The  Groundwater  Flow  Editor  dialog  is  invoked  when  the  Groundwater property  of  a
subcatchment is being edited. It is used to  link a subcatchment to both an aquifer and to a node
of the drainage system that exchanges groundwater with the aquifer. It also specifies coefficients
that determine the  rate of lateral  groundwater flow  between  the  aquifer and the node.  These
coefficients (A1, A2, B1, B2, and A3) appear in the following equation that computes groundwater
flow as a function of groundwater and surface water levels:
QL = Al(Hgw -
                         - A2(HSW -
                                                        A3HgwHsw
where:
    QL
    Hgw
    Hsw
    Hcb
       lateral groundwater flow (cfs per acre or cms per hectare)
       height of saturated zone above bottom of aquifer (ft or m)
       height of surface water at receiving node above aquifer bottom (ft or m)
       height of channel bottom above aquifer bottom (ft or m).
Note that QL can also be expressed in inches/hrfor US units.

The  rate of percolation to deep groundwater, QD, in in/hr (or mm/hr) is given by the following
equation:
                                            227

-------
       QD =LGLR

where  LGLR  is the lower groundwater loss rate  parameter assigned  to the subcatchment's
aquifer (in/hr or mm/hr) and HGS is the distance from the ground surface to the aquifer bottom (ft
or m).

In addition to the standard lateral flow equation, the dialog allows one to define a custom equation
whose  results will be added onto those of the standard equation. One can also define a custom
equation for deep groundwater flow that will replace the standard one. Finally, the dialog offers
the  option  to  override certain parameters  that were specified for the aquifer to which  the
subcatchment belongs. The properties listed in the editor are as follows:

Aquifer Name
Name of the aquifer object that describes the subsurface soil properties, thickness,  and  initial
conditions. Leave this field blank if you want the subcatchment not to generate any groundwater
flow.

Receiving Node
Name of node that receives groundwater from the aquifer.

Surface Elevation
Elevation of ground surface for the subcatchment that lies above the aquifer in feet or meters.

Groundwater Flow Coefficient
Value of A1 in the groundwater flow formula.

Groundwater Flow Exponent
Value of B1 in the groundwater flow formula.

Surface Water Flow Coefficient
Value of A2 in the groundwater flow formula.

Surface Water Flow Exponent
Value of B2 in the groundwater flow formula.

Surface-GW Interaction Coefficient
Value of A3 in the groundwater flow formula.

Surface Water Depth
Fixed depth of surface water above receiving node's invert (feet or meters). Set to zero if surface
water depth will vary as computed  by flow routing.

Threshold Water Table Elevation
Minimum water table elevation that must be reached before any flow occurs (feet or meters).
Leave blank to use the receiving node's invert elevation.
                                          228

-------
Aquifer Bottom Elevation
Elevation of the bottom of the aquifer below this particular subcatchment (feet or meters). Leave
blank to use the value from the parent aquifer.

Initial Water Table Elevation
Initial water table elevation at the start of the simulation for this particular subcatchment (feet or
meters). Leave blank to use the value from the parent aquifer.

Unsaturated Zone Moisture
Moisture content  of the unsaturated upper  zone above  the water table for  this particular
subcatchment at the start of the simulation (volumetric fraction). Leave  blank to use the value
from the parent aquifer.

Custom Lateral Flow Equation
Click the ellipsis button (or press Enter) to launch the Custom Groundwater Flow Equation editor
for lateral groundwater flow QL (see section C.7). The equation supplied by this editor will be used
in addition to the standard equation to compute groundwater outflow from the subcatchment.

Custom Deep Flow Equation
Click the ellipsis button (or press Enter) to launch the Custom Groundwater Flow Equation editor
for deep groundwater flow QD. The equation supplied by this editor will  be used to replace the
standard equation for deep groundwater flow.

The  coefficients supplied to the  groundwater flow equations must be in units that are consistent
with  the groundwater flow units, which can either be cfs/acre (equivalent to inches/hr) for US units
or cms/ha  for SI units.
       Note  that elevations are used to specify the ground  surface, water table height, and
       aquifer bottom  in the dialog's data entry fields  but that the groundwater flow equation
       uses depths above the aquifer bottom.

       If groundwater  flow is simply proportional to the difference in  groundwater and surface
       water heads, then set the Groundwater and Surface Water Flow Exponents (B1 and B2)
       to 1.0, set the  Groundwater Flow Coefficient (A1) to the proportionality factor, set the
       Surface Water  Flow Coefficient (A2) to the same value  as A1, and set the Interaction
       Coefficient (A3) to zero.

       Note that when conditions warrant, the groundwater flux can be negative, simulating flow
       into the aquifer from the channel, in  the manner of bank storage. An exception  occurs
       when A3 ^ 0, since the surface water - groundwater interaction term is usually derived
       from groundwater flow models that assume unidirectional flow.  Otherwise, to ensure that
       negative fluxes will  not occur, one can make A1 greater than or equal to A2, B1 greater
       than or equal to B2, and A3 equal to zero.

       To completely replace the standard groundwater flow equation  with the custom equation,
       set all of the standard equation coefficients to 0.
                                          229

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C.7    Groundwater Equation Editor
  ustom Groundwater Flow Equation Editor

  Enter an expression to use in addition to the standard equation for lateral groundwaterflow
  (leave blankto use only the standard equation):

  0.1*(Hgw-Hcb)*5TEP(Hgw-Hcb)
The  Groundwater  Equation  Editor  is  used  to  supply  a custom equation  for  computing
groundwater flow between the saturated sub-surface zone of a subcatchment and either a node
in the conveyance network (lateral flow) or to a deeper groundwater aquifer (deep flow). It is
invoked from the Groundwater Flow Editor form.

For lateral groundwater flow the result of evaluating the custom equation will be added onto the
result of the  standard equation.  To replace the standard equation completely set all  of its
coefficients to 0. Remember that lateral groundwater flow units  are  cfs/acre (equivalent to
inches/hr) for US units and cms/ha for metric units.

 The following symbols can be used in the equation:
    Hgw   (for height of the groundwater table)
    Hsw   (for height of the surface water)
    Hcb   (for height of the channel bottom)
    Hgs   (for height of the ground surface)
    Phi    (for porosity of the subsurface soil)
    Theta  (for moisture content of the upper unsaturated zone)
    Ks     (for saturated hydraulic conductivity in inches/hr or mm/hr)
    K      (for hydraulic conductivity at the current moisture content in inches/hr or mm/hr)
    Fi      (for infiltration rate from the ground surface in inches/hr or mm/hr)
    Fu     (for percolation rate from the upper unsaturated zone in inches/hr or mm/hr)
    A      (for subcatchment area in acres or hectares)
where all heights are relative to the aquifer's bottom elevation in feet (or meters).

The STEP function can be used to have flow only when the groundwater level is above a certain
threshold. For example, the expression:

  0.001  * (Hgw - 5) * STEP(Hgw - 5)

would generate flow only when Hgw was above 5. See Section C.22 (Treatment Editor) for a list
of additional math functions that can be used in a groundwaterflow expression.
                                           230

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C.8
Infiltration Editor
Inflation Editor B
Infiltration Method MORTON

Property
Max. Infil. Rate
Min. Infil. Rate
Decay Constant
Drying
Time
Max. Volume


Value
jl.2 |
0.1
2
7
0

Maximum rate on the Morton infiltration curve (in/hr or
mm/hr)


OK C


ancel Help

The Infiltration Editor dialog is used to specify values for the parameters that describe the rate at
which rainfall infiltrates into the upper soil zone in a subcatchment's pervious area.  It is invoked
when editing the Infiltration property  of a subcatchment. The infiltration parameters depend on
which infiltration model was selected for the project: Morton, Green-Ampt, or Curve Number.  The
choice of infiltration  model can be made either by editing the project's Simulation Options (see
Section 8.1) or by changing the project's Default Properties (see Section 5.4).


Morton Infiltration Parameters

The following data fields appear in the Infiltration Editor for Morton infiltration:

Max. Infil. Rate
Maximum infiltration rate on the Morton curve (in/hr or  mm/hr).  Representative  values are as
follows:
    A.   DRY soils  (with little or no vegetation):
        •   Sandy soils: 5 in/hr
        •   Loam soils: 3 in/hr
        •   Clay soils: 1 in/hr
    B.   DRY soils  (with dense vegetation):
        •   Multiply values in A. by 2
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    C.  MOIST soils:
        •    Soils which have drained but not dried out (i.e., field capacity):
            Divide values from A and B by 3.
        •    Soils close to saturation:
            Choose value close to minimum infiltration rate.
        •    Soils which have partially dried out:
            Divide values from A and B by 1.5 - 2.5.

Min. Infil. Rate
Minimum  infiltration rate on the Morton curve (in/hr or mm/hr).  Equivalent to the soil's saturated
hydraulic conductivity. See the Soil Characteristics Table in Section A.2 for typical values.

Decay Const.
Infiltration rate  decay constant for the Morton curve  (1/hours).  Typical values range  between 2
and 7.

Drying Time
Time in days for a fully saturated soil to dry completely. Typical values range from 2 to 14 days.

Max. Infil. Vol.
Maximum infiltration volume possible (inches or mm, 0 if not applicable). It can be estimated as
the difference between a soil's porosity and its wilting  point times the depth of the infiltration zone.


Green-Ampt Infiltration Parameters

The following data fields appear in the Infiltration Editor for Green-Ampt infiltration:

Suction Head
Average value of soil capillary suction along the wetting front (inches or mm).

Conductivity
Soil saturated hydraulic conductivity (in/hr or mm/hr).

Initial Deficit
Fraction of soil  volume that is initially dry (i.e., difference between soil porosity and initial moisture
content). For a  completely drained soil, it is the difference between the soil's porosity and its field
capacity.

Typical values  for  all  of these parameters  can be  found in the Soil Characteristics  Table in
Section A.2.
                                            232

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Curve Number Infiltration Parameters

The following data fields appear in the Infiltration Editor for Curve Number infiltration:

Curve Number
This  is the SCS  curve number which  is tabulated in the publication SCS Urban  Hydrology for
Small Watersheds, 2nd Ed., (TR-55), June 1986. Consult the Curve Number Table (Section A.4)
for a listing of values by soil group, and the accompanying Soil Group Table (Section A.3) for the
definitions of the various groups.

Conductivity
This  property has been deprecated and is no longer used.

Drying Time
The number of days it takes a fully saturated soil to dry.  Typical values range  between 2 and 14
days.
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C.9
Inflows Editor
The Inflows Editor dialog is used to assign Direct, Dry Weather, and RDM inflow into a node of the
drainage system. It is invoked whenever the Inflows property of a Node object is selected in the
Property Editor. The dialog consists of three tabbed pages that provide a  special editor for each
type of inflow.


Direct Inflows Page
 Inflows for Node 82309
    Direct
           Dry Weather  RDE
     Inflow =  (Baseline Value) x (Baseline Pattern) +

             [Time Series Value) x (Scale Factor)
      Constituent
               FLOW
      Baseline

      Baseline Pattern

      Time Series       82309_Inflow

      Scale Factor
              1.0
       If Baseline or Time Series is left blank its value is 0. If
           Baseline Pattern is left blank its value isl.O.
        Llgj[
The Direct page on the Inflows Editor dialog is used to specify the time history of direct external
flow and water quality entering a node of the drainage system.  These inflows are represented by
both a constant and time varying  component as follows:

Inflow at  time  t =  (baseline value) * (baseline pattern  factor)  +
                           (scale  factor) * (time series  value at time t)

The page  contains the following input fields that define the properties of this relation:
                                           234

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Constituent
Selects the constituent (FLOW or one of the project's specified pollutants) whose direct inflow will
be described.

Baseline
Specifies the value of the constant baseline component of the constituent's inflow. For FLOW, the
units are the project's flow units. For pollutants, the units are the pollutant's concentration units if
inflow  is a concentration, or can  be any  mass  flow  units if the inflow is a mass flow (see
Conversion Factor below). If left blank then no baseline inflow is assumed.

Baseline Pattern
An optional Time Pattern whose factors adjust the baseline inflow on  either an hourly,  daily, or
monthly basis (depending on the type of time pattern specified). Clicking the  ^ button will bring
up the Time Pattern Editor dialog for the selected time pattern. If left blank, then no adjustment is
made to the baseline inflow.

Time Series
Specifies the name of the time series that contains inflow data for the selected constituent. If left
blank then no direct inflow will occur for the selected constituent at the node in question.  You can
click the -^ button to bring up the Time Series Editor dialog for the selected time series.

Scale Factor
A multiplier used to adjust the values of the constituent's inflow time series. The baseline value is
not adjusted by this factor. The scale factor can have several uses, such as allowing one  to easily
change the magnitude of an inflow hydrograph while keeping its shape the same,  without having
to re-edit the entries  in the hydrograph time series. Or it can allow a group of nodes sharing the
same time series to  have their  inflows behave in  a time-synchronized fashion while letting their
individual magnitudes be different. If left blank the scale factor defaults to 1.0.

Inflow Type
For pollutants,  selects the  type of inflow data  contained in the time series as  being  either a
concentration (mass/volume) or mass flow rate (mass/time). This field does not appear for FLOW
inflow.

Conversion Factor
A numerical factor used to convert the units of pollutant mass flow rate in the time series data into
concentration mass units per second. For example, if the time series data were in pounds per day
and the pollutant concentration defined  in the project was mg/L, then the conversion factor value
would be (453,590 mg/lb) / (86400 sec/day) = 5.25 (mg/sec) per (Ib/day).

More than one  constituent can  be edited while  the dialog is active by simply selecting another
choice for the Constituent property. However, if the Cancel button is clicked then any changes
made to all constituents will be ignored.
                                           235

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        If a pollutant is assigned a direct  inflow in terms  of concentration, then one must also
        assign a direct inflow to flow, otherwise no pollutant inflow will occur. An exception is at
        submerged outfalls where pollutant intrusion can occur during periods of reverse flow. If
        pollutant inflow is defined in terms of mass, then a flow inflow time series is not required.
Dry Weather Inflows Page
 Inflows for Node 82309
    Direct  Dry Weather  RDB
      Inflow = (Average Value) x (Pattern 1) x

             (Pattern 2) x [Pattern 3) x (Pattern 4)
      Constituent

      Average Value
      (CFS)

      Time Patterns
FLOW
12

Monthlyl
                       Hourlyl
       If Average Value is left blank its value is 0. Any Time
       Pattern left blank defaults to a constant value of 1.0.
The Dry Weather page of the Inflows Editor dialog  is used to specify a continuous source of dry
weather flow entering a node of the drainage system. The page contains the following input fields:

Constituent
Selects the constituent (FLOW or one of the  project's  specified pollutants) whose dry weather
inflow will be specified.
                                            236

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Average Value
Specifies the average (or baseline)  value  of the dry weather  inflow of the constituent in the
relevant units (flow units for flow, concentration units for pollutants). Leave blank if there is no dry
weather flow for the selected constituent.

Time Patterns
Specifies the names of the time patterns to be used to allow the dry weather flow to vary in a
periodic fashion by month of the year, by day of the week, and by time of day (for both weekdays
and weekends). One  can either type in a name or select a previously defined  pattern from the
dropdown list of each  combo box. Up to four different types of patterns can be assigned. You can
click the  & button next to each Time Pattern field to edit the respective pattern.

More than one  constituent can be  edited while the  dialog is active by simply selecting another
choice for the Constituent property. However, if the Cancel button  is clicked then any changes
made to all constituents will be ignored.
RDM Inflow Page
 Inflows for Node 82309
    Direct  | Dry Weather
ROE
            Unit Hydrograph Group

             UH-1
            Sewershed Area
            (acres)
          20

     Leave the Unit Hydrograph Group field blank to remove
                 any RDE inflow at this node.
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The RDM Inflow page of the Inflows Editor dialog form is used to specify RDM (Rainfall Dependent
Infiltration/Inflow) for the node in question. The page contains the following two input fields:

Unit Hydrograph Group
Enter (or select from the dropdown list) the name of the Unit Hydrograph group that applies to the
node  in question. The unit hydrographs in the group are used  in combination  with the group's
assigned rain gage to develop  a time series of RDM inflows per unit area over the period of the
simulation.  Leave this field blank to indicate that the node receives no  RDM inflow. Clicking the
•^ button will launch the Unit Hydrograph Editor for the UH group specified.

Sewershed Area
Enter the area (in acres or  hectares) of the sewershed that contributes  RDM to  the node  in
question. Note this area will typically be only a small, localized portion of the subcatchment  area
that contributes surface runoff to the node.
                                          238

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C.10 Initial Buildup Editor
Property
Infiltration
Groundwater
Snow Pack
LJD Control:
Land Uses
(Initial Buildup
Curb Length
Value |
MORTON *1
NO

0
1
YES ...\\-
0
I I
Initial pollutant buildup on
subcatchment (click to edit)



Initial Buildup Editor
Pollutant Initial Buildup (Ibs/ac)
TSS 10
Lead

Enter initial buildup of pollutants on
subcatchment 1
OK Cancel Help

The  Initial Buildup Editor is invoked from the Property Editor when editing the Initial Buildup
property  of  a subcatchment.  It specifies the amount  of  pollutant  buildup existing  over the
subcatchment at the start of the simulation. The editor consists  of a data entry grid with two
columns. The first column lists the name of each pollutant in the project and the second column
contains  edit boxes for entering the  initial buildup values. If no buildup value  is supplied  for a
pollutant, it is assumed to be 0. The  units for buildup are either pounds per acre when US  units
are in use or kilograms per hectare when SI metric units are in use.

If a non-zero value is specified for  the initial  buildup of a pollutant,  it  will override any  initial
buildup computed from the Antecedent Dry Days  parameter specified on the Dates page of the
Simulation Options dialog.
                                           239

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C.11   Land Use Editor

The Land Use Editor dialog is used to define a category of land use for the study area and to
define its pollutant buildup and washoff characteristics. The dialog contains three tabbed pages of
land use  properties:
    •   General Page (provides land use name and street sweeping parameters)
    •   Buildup Page (defines rate at which pollutant buildup occurs)
    •   Washoff Page (defines rate at which pollutant washoff occurs)


General Page
General Buildup | Washoff
Property
Value
Land Use Name jResidential
Description

STREET SWEEPING
Interval
Availability
Last Swept




User assigned name of land use.
The General page of the Land Use Editor dialog describes the following properties of a particular
land use category:

Land  Use Name
The name assigned to the land use.

Description
An optional comment or description of the land  use (click the ellipsis button or press Enter to
edit).

Street Sweeping Interval
Days  between street sweeping within the land use.
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Street Sweeping Availability
Fraction of the buildup of all pollutants that is available for removal by sweeping.

Last Swept
Number of days since last swept at the start of the simulation.

If street sweeping does not apply to the land use, then the last three properties can be left blank.


Buildup Page
 Land Use Editor
General Buildup Washoff
Pollutant
Property
Function
Max, Buildup
Rate Constant
Power/Sat. Constant
Normalizer
TSS
Value
SAT
50
0
2
AREA

Buildup function: ROW = power, EXP =
exponential, SAT = saturation, EXT = external time
series.
The Buildup page of the Land Use Editor dialog describes the properties associated with pollutant
buildup over the land during dry weather periods. These consist of:

Pollutant
Select the pollutant whose buildup properties are being edited.

Function
The type of buildup function to use for the pollutant. The choices are NONE  for no buildup, POW
for power function  buildup, EXP  for exponential  function buildup  SAT for saturation function
buildup, and EXT for buildup supplied by an external time series. See the discussion of Pollutant
Buildup in Section 3.3.9 Land Uses for explanations of these different functions. Select NONE if no
buildup occurs.
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Max. Buildup
The maximum buildup that can occur, expressed as Ibs (or kg) of the pollutant per unit of the
normalizer variable  (see  below). This is the same as  the C1  coefficient used in the buildup
formulas discussed in Section 3.3.9.

The following two properties apply to the POW, EXP, and SAT buildup functions:

Rate Constant
The time constant that governs the rate of pollutant buildup. This is the  C2 coefficient in the
Power and Exponential buildup formulas discussed in Section 3.3.9. For Power buildup its  units
are mass / days raised to a power, while for Exponential buildup its units are 1/days.

Power/Sat. Constant
The exponent C3  used in the Power buildup formula, or the half-saturation constant C2 used in
the Saturation buildup formula discussed in Section 3.3.9. For the latter case, its units are days.

The following two properties apply to the EXT (External Time Series) option:

Scaling Factor
A multiplier used to adjust the buildup rates listed in the time series.

Time Series
The name of the Time Series that contains buildup rates (as mass per normalizer per day).

Normalizer
The variable to which buildup is normalized on a per unit basis. The choices are either land  area
(in acres or hectares) or curb length. Any units of measure can  be used for curb length, as  long
as they remain the same for all subcatchments in the project.

When  there  are multiple pollutants, the user must select each  pollutant separately  from the
Pollutant dropdown list and specify its pertinent buildup properties.
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Washoff Page
 Land Use Editor
General Buildup Washoff
Pollutant
Property
TSS
Value
Function JEXP
Coefficient
Exponent
Cleaning Effic,
BMP Effic.
0.1
1
0
0

   Washoff function: EXP = exponential, RC = rating
   curve, EMC = event mean concentration.
The  Washoff page of the  Land Use Editor  dialog describes the properties associated  with
pollutant washoff over the land use during wet weather events. These consist of:

Pollutant
The name of the pollutant whose washoff properties are being edited.

Function
The choice of washoff function to use for the pollutant. The choices are:
    •  NONE   no washoff

    •  EXP    exponential washoff

    •  RC     rating curve washoff

    •  EMC    event-mean concentration washoff.
The formula for each of these functions is discussed in Section 3.3.9 Land   Uses   under   the
Pollutant Washoff topic.

Coefficient
This is  the  value of C1  in the exponential and  rating  curve formulas,  or the  event-mean
concentration.

Exponent
The exponent used in the exponential and rating curve washoff formulas.
                                          243

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Cleaning Efficiency
The street cleaning removal efficiency (percent) for the pollutant. It represents the fraction of the
amount that is available for removal on the land use as a whole (set on the General page of the
editor) which is actually removed.

BMP Efficiency
Removal efficiency (percent) associated with any Best Management Practice  that might have
been implemented. The washoff load  computed at  each time step is simply  reduced by this
amount.

As with the Buildup page, each pollutant must be selected in turn from the Pollutant dropdown list
and have its pertinent washoff properties defined.
C.12   Land Use Assignment Editor
Sub catchment 2
Property
Infiltration
Ground water
Snow Pack
LJD Controls
ILand Uses
Initial Buildup
Curb Length
1
d
Value |
MORTON
NO

0
i2 ... 1
? \
NONE
0

Assignment of land uses to
subcatchment (click to edit)




Land Use Assignment
Land Use % of Area
Residential 150.00 j
Undeveloped 50.00



OK Cancel Help

The Land Use Assignment editor is invoked from the Property Editor when editing the Land Uses
property of a subcatchment.  Its purpose is to assign land uses to the subcatchment for water
quality simulations. The percent of land  area in the subcatchment covered by each land use is
entered next to its respective  land use category. If the land use is not present its field can be left
blank. The percentages entered do not necessarily have to add up to 100.
                                          244

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C.13    LID Control Editor
  LID Control Editor
   Control Name:   planters
   LID Type;
Bio-Retention Cell
                                 Drain*
                             Surface  Soil
              Storage  Drain
Thickness
(in, or mm)
Porosity
(volume fraction)

Field Capacity
(volume fraction)

Wilting Point
(volume fraction)
Conductivity
(in/hr or mm/hr)

Conductivity
Slope

Suction Head
(in, or mm)
                                                                    12
                                                                    05
                                                                    10.0
                                                                    35
The LID Control Editor is used to define a low impact development control that can be deployed
throughout a study area to store, infiltrate, and evaporate subcatchment runoff. The design of the
control is made on a per-unit-area basis so that it can be placed in any number of subcatchments
at different sizes or number of replicates. The editor contains the following data entry fields:

Control Name
A name used to identify the particular LID control.

LID Type
The generic type of LID  being  defined  (bio-retention cell, rain garden, green  roof, infiltration
trench, permeable pavement, rain barrel, or vegetative swale).

Process Layers
These are a tabbed set of  pages containing  data entry fields for the vertical layers and drain
system that comprise an LID control. They include  some combination of the following, depending
on the type of LID selected: Surface  Layer,  Pavement  Layer, Soil  Layer, Storage Layer, and
Drain  System or Drainage Mat.


Surface Layer Properties

The Surface Layer page of the LID Control Editor is used to describe the surface properties of all
types  of LID controls except  rain barrels. Surface layer properties include:
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Berm Height (or Storage Depth)
When confining walls or berms are present this is the maximum depth to which water can pond
above  the surface of the  unit before  overflow occurs  (in inches  or  mm).  For Rooftop
Disconnection it is the roofs depression storage depth, and for Vegetative Swales it is the height
of the trapezoidal cross section.

Vegetative Volume Fraction
The fraction of the volume within the storage depth filled with vegetation. This is the volume
occupied by stems and leaves, not their surface area coverage. Normally this  volume can be
ignored, but may be as high as 0.1 to 0.2 for very dense vegetative growth.

Surface Roughness
Manning's n for overland flow over surface soil cover, pavement, roof surface or vegetative swale.
Use 0 for other types of LIDs.

Surface Slope
Slope of a roof surface, pavement surface or vegetative swale (percent). Use 0 for other types of
LIDs.

Swale Side Slope
Slope (run over rise) of the side walls of a vegetative swale's cross section. This value is ignored
for other types of LIDs.
       If either Surface Roughness or Surface Slope values are 0 then any ponded water that
       exceeds the surface storage depth is  assumed to completely overflow the LID control
       within a single time step.
Pavement Layer Properties

The Pavement Layer page of the LID Control Editor supplies values for the following properties
of a permeable pavement LID:

Thickness
The thickness of the pavement layer (inches or mm). Typical values are 4 to 6 inches (100 to 150
mm).

Void Ratio
The volume of void space relative to the volume of solids in the pavement for continuous systems
or for the fill material used in modular systems. Typical values for pavements are 0.12 to 0.21.
Note that porosity = void ratio / (1 + void ratio).

Impervious Surface Fraction
Ratio  of impervious paver  material to total area  for modular systems;  0 for continuous porous
pavement systems.
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Permeability
Permeability of the concrete or asphalt used in continuous systems or hydraulic conductivity of
the fill  material (gravel  or sand) used in modular systems (in/hr or mm/hr). The  permeability of
new porous concrete or asphalt is very high (e.g., hundreds of in/hr) but can drop off over time
due to  clogging by fine particulates in the runoff (see below).

Clogging Factor
Number  of pavement  layer void volumes of runoff treated  it takes to  completely  clog  the
pavement. Use a value of 0 to ignore clogging. Clogging progressively reduces the pavement's
permeability in direct proportion to the cumulative volume of runoff treated.

If one  has  an estimate of the number of years it takes  to fully clog the system (Yclog),  the
Clogging Factor can be computed as: Yclog * Pa * CR * (1 + VR) * (1 - ISF) / (T * VR) where Pa
is  the  annual rainfall amount over the site,  CR is  the  pavement's  capture ratio (area that
contributes  runoff to the pavement divided by area of the pavement itself), VR is the system's
Void Ratio,  ISF is the Impervious Surface Fraction, and T is the  pavement layer Thickness.

As an  example,  suppose  it takes 5 years to  clog a continuous porous pavement system that
serves an area where the annual rainfall is 36 inches/year. If the pavement is 6 inches thick, has
a void  ratio of 0.2 and captures runoff only from  its own surface, then the Clogging Factor is 5 x
36x(1 +0.2)76/0.2 = 180.


Soil Layer properties

The  Soil Layer page of the LID Control Editor describes the  properties of the engineered soil
mixture used  in  bio-retention types of LIDs and  the optional sand  layer beneath permeable
pavement. These properties are:

Thickness
The thickness of the soil layer (inches or mm).  Typical values range from 18 to 36 inches (450 to
900 mm) for rain gardens, street planters and other types of land-based bio-retention units, but
only 3 to 6 inches (75 to 150 mm) for green roofs.

Porosity
The volume of pore space relative to total volume of soil (as a fraction).

Field Capacity
Volume of pore water relative to total volume after the soil has been  allowed to drain fully (as a
fraction).  Below this level, vertical drainage of water through the soil layer does not occur.

Wilting Point
Volume of pore water relative to total volume for a well dried soil where only bound water remains
(as a fraction). The moisture content of the soil cannot fall below this limit.

Conductivity
Hydraulic conductivity for the fully saturated soil (in/hr or mm/hr).
                                          247

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Conductivity Slope
Slope of the curve of log(conductivity) versus soil  moisture  content (dimensionless). Typical
values range from  30  to 60. It can  be estimated from a standard soil grain  size analysis as
0.48(%Sand) + 0.85(%Clay).

Suction Head
The  average value  of soil capillary suction along the wetting front (inches or  mm). This  is the
same parameter as  used in the Green-Ampt infiltration model.

  r,
       Porosity, field capacity,  conductivity and conductivity slope are the same soil properties
       used for Aquifer objects when modeling groundwater, while suction head is the same
       parameter used for  Green-Ampt infiltration. Except here they apply to the special soil
       mixture used in a LID unit rather than the site's naturally occurring soil. See Appendix A.2
           Soil Characteristics for typical values of these properties.


Storage Layer Properties

The Storage Layer page of  the LID Control Editor describes the properties of the crushed stone
or gravel layer used in bio-retention cells, permeable pavement systems,  and infiltration trenches
as a  bottom storage/drainage layer. It is also used to specify the height of  a rain barrel  (or
cistern). The following data fields are displayed:

Thickness (or Barrel Height)
This is the thickness of a gravel  layer or the height of a rain barrel (inches or mm). Crushed stone
and gravel  layers are typically 6 to 18 inches (150 to 450 mm) thick while single family home rain
barrels range in height from 24 to 36 inches (600 to 900 mm).

The following data fields do not apply to Rain Barrels.

Void Ratio
The volume of void  space  relative to the volume of solids in the layer. Typical values range from
0.5 to 0.75  for gravel beds. Note that porosity = void ratio / (1 + void ratio).

Seepage Rate
The  rate  at which water  seeps into the  native  soil  below  the layer (in inches/hour or
mm/hour).This would typically  be the  Saturated Hydraulic  Conductivity  of  the surrounding
subcatchment  if Green-Ampt infiltration  is used  or the Minimum  Infiltration  Rate for Morton
infiltration. If there is an impermeable floor or liner below the layer then use a value of 0.

Clogging Factor
Total volume of treated runoff it takes to completely clog the bottom of the layer divided by the
void  volume of the layer. Use a value of 0 to ignore clogging. Clogging progressively reduces the
Infiltration Rate in direct proportion to the cumulative volume of runoff treated and may only be of
concern for infiltration trenches with permeable bottoms and no under drains.
                                           248

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Storage Drain Properties

LID storage layers can contain an optional drainage system that collects water entering the layer
and conveys  it to a conventional storm drain or other location (which  can be different than the
outlet of the LID's subcatchment). Drain flow can also be returned it to the pervious area of the
LID's  subcatchment. The drain can be offset some distance above the bottom of the storage
layer, to allow some volume of runoff to be stored (and eventually infiltrated) before any excess is
captured by the drain. For Rooftop Disconnection, the drain system consists of the roofs gutters
and downspouts that have some maximum conveyance capacity.

The Drain page of the LID Control Editor describes the properties of this system. It contains the
following data entry fields:

Drain Coefficient and Drain Exponent
The drain coefficient C and exponent n determines the rate of flow through a drain as a function
of the height  of stored water above the drain's offset. The following equation is used to compute
this flow rate  (per unit area of the LID unit):
    q = Chn
where q is outflow (in/hr or mm/hr) and h is the height of saturated media above the drain (inches
or mm). A typical value for n would be 0.5 (making the drain act like an orifice). Note that the units
of C depend  on the unit system being  used as well as the value assigned to n. If the layer has
no drain then set Cto 0

Drain Offset  Height
This is the  height of the drain  line above the bottom of a storage  layer or rain barrel (inches or
mm).

Drain Delay (for Rain Barrels only)
The number of dry weather hours that must elapse before the drain line in a rain barrel is opened
(the line is assumed to be closed once rainfall begins). A value of 0 signifies that the barrel's drain
line is always open and drains continuously. This parameter is ignored for other types of LIDs.

Flow Capacity (for Rooftop Disconnection only)
This is the maximum flow rate  that the roofs gutters  and downspouts can handle (in inches/hour
or mm/hour) before overflowing. This is the only drain parameter used for Rooftop Disconnection.

There are several things to keep in mind when specifying the parameters of an LID's underdrain:

    •    If the storage layer that contains  the drain has an impermeable bottom then it's best to
        place the drain at the bottom with a zero  offset. Otherwise, to  allow the full storage
       volume to fill before draining occurs, one would place the drain at the top of the storage
        layer.
    •    If the storage layer has no drain then set the drain coefficient to 0.
    •    If the drain can carry whatever flow enters the storage  layer up to some specific limit then
       set the drain coefficient to the limit and the drain exponent to 0.
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    •   If the underdrain consists of slotted pipes where the slots act as orifices, then the drain
        exponent would be 0.5 and the drain coefficient would be 60,000 times the ratio of total
        slot area to  LID area.  For example, drain  pipe with five  1/4" diameter holes per foot
        spaced 50 feet apart would have an area ratio of 0.000035 and a drain coefficient of 2.
    •   If the goal is to drain a fully saturated unit in a specific amount of time then set the drain
        exponent to 0.5 (to represent orifice flow) and the  drain coefficient to 2D1/2/T where D is
        the distance from the drain to the surface plus any berm height (in inches or mm) and T is
        the time in hours to drain. For example, to drain a depth of 36 inches in 12 hours requires
        a drain  coefficient of  1.  If this drain consisted of the  slotted  pipes described  in the
        previous  bullet, whose coefficient was 2, then a flow regulator, such as a cap orifice,
        would have to be placed on the drain outlet to achieve the reduced flow rate.


Drainage Mat Properties

Green Roofs usually contain a  drainage mat or plate that lies below the soil media and above the
roof structure. Its purpose is to convey any water that drains through the soil  layer off of the  roof.
The Drainage Mat page of the LID Control Editor for Green Roofs lists the properties of this layer
which include:

Thickness
The thickness of the mat or plate (inches or mm). It typically ranges between 1  to 2 inches.

Void Fraction
The ratio of void volume to total volume in the mat. It typically ranges from 0.5 to 0.6.

Roughness
This is  the  Manning's n constant used to compute the horizontal flow rate of drained water
through the  mat.  It is  not  a  standard product  specification provided by  manufacturers  and
therefore must  be estimated. Previous  modeling studies have suggested using a  relatively  high
value such as from 0.1 to 0.4.
                                           250

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C.14    LID Group Editor
  LID Controls for Subcatchment SI
     Control Name   LID Type       % of Area      %FromImperv  Report File

     InfilTrench      Infil. Trench     1.074          40

     RainBarrels      Rain Barrel
0.081
17
                                                     OK
The LID Group Editor is invoked when the LID Controls property of a Subcatchment is selected
for editing. It is used to identify a group of previously defined LID controls that will  be placed
within the Subcatchment, the sizing of each control, and what percent of runoff from the non-LID
portion of the Subcatchment each should treat.

The editor displays the current group of LIDs placed in the Subcatchment along  with buttons for
adding an LID unit, editing a selected unit, and deleting a selected unit. These actions can also
be chosen by hitting  the Insert key, the Enter key, and the Delete key, respectively. Selecting
Add or Edit  will bring up  an LID Usage Editor where one can enter values for the data fields
shown in the  Group Editor.

Note that the total % of Area for all  of the LID units within a Subcatchment must not exceed
100%. The same applies to % From Impervious. Refer to the LID Usage Editor  for the meaning
of these parameters.
                                           251

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C.15    LID Usage Editor
 LID Usage Editor
   LID Control Name     RainBarrels
   Detailed Report File (Optional)
D LID Occupies Full Subcatchment

Area of Each Unit (sq ft or sq m)

Number of Units

% of Subcatchment Occupied

Surface Width per Unit (ft or m)

% Initially Saturated

% of Impervious Area Treated
                                                                             32

                                                                             0.081
                                                                                     "H
                                                                             17
                                                  Send Drain Flow To:
                                                  (Leave blank to use outlet of current Subcatchment)
                                                  J Return all Outflow to Pervious Area
                                                          OK
                               Help
The  LID Usage Editor  is invoked from  a subcatchment's LID Group Editor to  specify how a
particular LID control will be deployed within the Subcatchment. It contains the following data
entry fields:

Control Name
The  name of a previously defined LID control to be used in the Subcatchment. (LID controls are
added to a project by using the Project Browser.)

LID Occupies Full Subcatchment
Select  this checkbox option  if the LID control occupies the full Subcatchment (i.e., the LID  is
placed in its own separate Subcatchment  and accepts runoff from upstream subcatchments).

Area of Each Unit
The  surface area devoted to each replicate LID unit (sq. ft or sq. m). If the LID Occupies Full
Subcatchment  box is  checked, then this field becomes disabled  and will  display the total
Subcatchment area divided by the number of replicate units. (See Section 3.3.14 LID Controls  for
options on placing LIDs within subcatchments.) The label below this field indicates how much  of
the total Subcatchment area is devoted to the particular LID being deployed and gets updated as
changes are made to the number of units and area of each unit.

Number of Replicate Units
The  number of equal size units of the LID practice (e.g., the number of rain barrels)  deployed
within the Subcatchment.
                                            252

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Surface Width Per Unit
The width of the outflow face of each  identical LID unit (in ft or m). This parameter applies to
roofs, pavement, trenches, and swales  that use overland flow to convey surface runoff off of the
unit. It can be set to 0 for other LID processes, such as bio-retention cells, rain gardens, and rain
barrels that simply spill any excess captured runoff over their berms.

% Initially Saturated
For bio-retention cells, rain gardens, and green roofs this is the degree to which the unit's soil is
initially filled with water (0 % saturation corresponds to the wilting point moisture content, 100 %
saturation has the moisture content equal to the porosity). The  storage  zone beneath the soil
zone  of the  cell is  assumed to be completely dry. For other types of LIDs it corresponds to the
degree to which their storage zone is initially filled with water.

% of Impervious Area Treated
The percent of the  impervious portion of the subcatchment's non-LID area whose runoff is treated
by the LID practice. (E.g., if rain barrels are used to capture roof runoff and roofs represent 60%
of the impervious area, then the impervious area treated is 60%). If the LID unit treats only direct
rainfall, such as with a green roof or roof disconnection, then this value should be 0. If the LID
takes  up the entire subcatchment then this field is ignored.

Send  Drain Flow To
Provide the name of the Node or Subcatchment that receives any drain flow produced by the LID
unit.   This field  can  be  left blank if  this flow goes to  the  same  outlet as  the  LID unit's
subcatchment.

Return All Outflow to Pervious Area
Select this option if outflow from the LID unit should be routed back onto the pervious area of the
subcatchment that contains  it. If drain  outflow was selected to be routed to a different location
than the  subcatchment outlet then only surface outflow will be returned. Otherwise both surface
and drain flow will be returned. Selecting this option would be a common choice to make for Rain
Barrels, Rooftop Disconnection and possibly Green  Roofs.

Detailed Report File
The name of an optional file where detailed time series results for the LID will be written. Click the
browse button 4l  to select a file using the standard Windows File Save dialog or click the delete
button X to remove any detailed reporting. The detailed report file will be a tab delimited text file
that can  be easily opened and viewed with  any text  editor or spreadsheet program (such as
Microsoft Excel) outside of SWMM.
                                           253

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C.16    Pollutant Editor
Pollutant Editor |-£3-
Property Value
Name
Units
Rain Concen.
GW Concen.
I&I Concen.
DWF Concen.
Init. Concen.
Decay Coeff.
Snow Only
Co-Pollutant
Co-Fraction
Lead
UG/L
0.0
0.0
0
0
0
0.0
NO
TSS
02
User-assigned name of the pollutant.
| OK i Cancel Help

The Pollutant Editor is invoked when a new pollutant object is created or an existing pollutant is
selected for editing. It  contains the following fields:

Name
The name assigned to the pollutant.

Units
The concentration units (mg/L, ug/L,  or #/L (counts/L)) in which the pollutant concentration is
expressed.

Rain Concentration
Concentration of the pollutant in rain water (concentration units).

GW Concentration
Concentration of the pollutant in ground water (concentration units).

Initial Concentration
Concentration of the pollutant throughout the conveyance system at the start of the simulation.
                                           254

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l&l Concentration
Concentration of the pollutant in any Infiltration/Inflow (concentration units).

DWF Concentration
Concentration of the pollutant in any dry weather sanitary flow (concentration units). This value
can be overridden for any specific node of the conveyance system by editing the node's Inflows
property.

Decay Coefficient
First-order decay coefficient of the pollutant (1/days).

Snow Only
YES if pollutant buildup occurs only when there is snow cover, NO otherwise (default is NO).

Co-Pollutant
Name of another pollutant whose runoff concentration contributes to the runoff concentration of
the current pollutant.

Co-Fraction
Fraction of the  co-pollutant's  runoff concentration that contributes to the runoff concentration of
the current pollutant.

An example of a co-pollutant  relationship would be where the runoff concentration of a particular
heavy metal is  some fixed fraction of the runoff concentration of suspended solids. In this case
suspended solids would be declared as the co-pollutant for the heavy metal.
                                           255

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C.17   Snow Pack Editor

The Snow Pack Editor is invoked when a new snow pack object is created or an existing snow
pack is selected for editing. The editor contains a data entry field for the snow pack's name and
two tabbed pages, one for snow pack parameters and one for snow removal parameters.
 Snow Pack Editor
    Snow Pack Name
                       SP1
     Snow Pack Parameters  Snow Removal Parameters
Subcatchment Surface Type
Min. Melt Coeff. (in/hr/deg F)
Max. Melt Coeff. (in/hr/deg F)
Base Temperature (deg F)
Fraction Free Water Capacity
Initial Snow Depth (in)
Initial Free Water (in)
Depth at 100% Cover (in)
Plowable
0.001
0.001
32.0
010
0.00
0,00

Impervious
0.001
0.001
32JO
010
0.00
0.00
0.00
Pervious
0.001
0.001
32.0
0.10
0.00
0.00
0.00
     Fraction of Impervious Area That is Plowable:
0.0
Snow Pack Parameters Page

The Parameters page of the Snow Pack Editor dialog provides snow melt parameters and initial
conditions for snow that accumulates over three different types of areas: the impervious area that
is  plowable  (i.e.,  subject to snow removal), the remaining impervious area,  and the entire
pervious area. The page contains a data entry grid which has a column for each type of area and
a row for each of the following parameters:

Minimum  Melt Coefficient
The degree-day snow melt coefficient that occurs on December 21. Units are either in/hr-deg  F or
mm/hr-deg C.
                                          256

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Maximum Melt Coefficient
The degree-day snow melt coefficient that occurs on  June 21. Units are either in/hr-deg F or
mm/hr-deg  C.  For a short term simulation of less than a week or so it is acceptable to use a
single value for both the minimum and maximum melt coefficients.

The minimum and maximum snow melt coefficients are used to estimate a melt coefficient that
varies by day of the year. The latter is used in the following degree-day equation to compute the
melt rate for any particular day:
    Melt Rate = (Melt Coefficient) * (Air Temperature - Base Temperature).

Base Temperature
Temperature at which snow begins to melt (degrees F or C).

Fraction Free Water Capacity
The volume of a snow  pack's pore  space which must fill with melted snow before  liquid runoff
from the pack begins, expressed as a fraction of snow pack depth.

Initial Snow Depth
Depth of snow at the start of the simulation  (water equivalent depth in inches or millimeters).

Initial Free Water
Depth of melted water  held within the pack at the start of the simulation  (inches or mm). This
number should be at or below the product of the initial snow depth and the fraction free water
capacity.

Depth at 100% Cover
The depth of snow beyond which the entire area remains completely covered  and is not subject
to any areal depletion effect (inches or mm).

Fraction of Impervious Area That is Plowable
The fraction of impervious area that is plowable and therefore is not subject to areal depletion.
                                          257

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Snow Removal Parameters Page
 Snow Pack Editor
    Snow Pack Name
                        SP1
     Snow Pack Parameters  Snow Removal Parameters
             Depth at which snow removal begins (in)
             Fraction transferred out of the watershed
             Fraction transferred to the impervious area
             Fraction transferred to the pervious area
             Fraction converted into immediate melt
             Fraction moved to another subcatchment
1.0


0,0
0,0
0,0
0,0
0,0
             (Subcatchment name)
             Note: sum of all fractions must be <= 1.0.
The Snow Removal page of the Snow Pack Editor describes how snow removal occurs within the
Plowable area of a snow pack. The following parameters govern this process:

Depth at which snow removal begins (in or mm)
Depth which must be reached before any snow removal begins.

Fraction transferred out of the watershed
The fraction of snow depth that is removed from the system (and does not become runoff).

Fraction transferred to the impervious area
The fraction of snow depth that is added to snow accumulation on the pack's impervious area.

Fraction transferred to the pervious area
The fraction of snow depth that is added to snow accumulation on the pack's pervious area.
                                          258

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Fraction converted to immediate melt
The fraction of snow  depth  that becomes liquid  water which runs onto any subcatchment
associated with the snow pack.

Fraction moved to another subcatchment
The  fraction  of  snow  depth  which  is added  to the snow accumulation  on  some  other
subcatchment. The name of the subcatchment must also be provided.

The various removal fractions must add up to 1.0 or less. If less than 1.0, then some remaining
fraction of snow depth will be left on the surface after all of the redistribution options are satisfied.
                                         259

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C.18   Time Pattern Editor
 Time Pattern Editor
   Name
Type
    DWF
 HOURLY
   Description
    Global hourly DWF pattern
   Multipliers
12AM
1AM
2AM
BAM
4AM
5AM
6AM
7AM
.0151 N
.01373
.01812
.01098
.01098
.01922
.02773
.03789
The Time Pattern Editor is invoked when a new time pattern object is created or an existing time
pattern is selected for editing. The editor contains that following data entry fields:

Name
Enter the name assigned to the time pattern.

Type
Select  the type of time pattern being specified.  The choices are Monthly, Daily,  Hourly and
Weekend Hourly.

Description
You can provide an optional comment or description for the time pattern. If more than one line is
needed, click the & button to launch a multi-line comment editor.

Multipliers
Enter a value for each  multiplier. The number and meaning of the multipliers changes with the
type of time pattern selected:
   •   MONTHLY       One multiplier for each month of the year.
   •   DAILY         One multiplier for each day of the week.
   •   HOURLY        One multiplier for each hour from  12 midnight to 11  PM.
   •   WEEKEND       Same as for HOURLY except applied to weekend days.
                                          260

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        In order to maintain an average dry weather flow or pollutant concentration at its specified
        value (as entered on the Inflows Editor), the multipliers for a pattern should average to
        1.0.
C.19    Time Series Editor

 Time Series Editor

   Time Series Name
    82309
   Description
    Direct inflow at Node 82309
      Use external data file named below
    J Enter time series data in the table below

    No dates means times are relative to start of simulation.
Date
(M/D/V)











Time
(H:M)
0
0.25
3JO
325
12JO






Value
0
40
40
0
0






>










T
The Time Series Editor is invoked whenever a new time series object is created or an existing
time series is selected for editing. To use the Time Series Editor:

    l.  Enter values for the following standard items:
        Name          Name of the time series.
        Description     Optional comment or description of what the  time series  represents.
                       Click the &  button to launch a multi-line comment editor if more than
                       one line is needed.
                                            261

-------
2.  Select whether to use  an external file as the  source of the data or to  enter the data
    directly into the form's data entry grid.
                                                Cjk
3.  If the external  file option  is selected, click the  « button to locate the file's name. The
    file's contents  must be formatted in the same manner as the direct data entry  option
    discussed below. See the description of Time Series Files in Section 11.6    Time  Series
    Files for details.
4.  For direct data entry, enter values in the data entry grid as follows:
    Date Column   Optional date (in month/day/year format) of the time  series values (only
                  needed at points in time where a new date occurs).
    Time Column   If dates are used, enter the military time of day for each time series value
                  (as hours:minutes or decimal hours). If dates are not  used, enter time as
                  hours since the start of the simulation.
    Value Column  The time series' numerical values.
    A graphical plot of the data in the grid can be viewed in a separate window by clicking the
    View button. Right clicking over the grid will make a popup Edit menu appear. It contains
    commands  to cut, copy, insert, and paste selected cells in the grid as well as options to
    insert or delete a  row.
5.  Press OK to accept the time series or Cancel to cancel your edits.
    Note that there are two methods for describing the occurrence time of time series data:
    as calendar date/time of day (which requires that at least one date, at the start of the
    series,  be entered in the Date column)
    as elapsed hours since the start  of the simulation  (where  the  Date column  remains
    empty).
    For rainfall time series,  it  is  only  necessary to enter periods  with  non-zero rainfall
    amounts.  SWMM interprets the rainfall  value  as a  constant value  lasting  over the
    recording interval specified for the rain gage which utilizes the time series. For all other
    types  of time series, SWMM  uses interpolation to estimate values at times that fall  in
    between the recorded values.
                                       262

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C.20    Title/Notes Editor
   gjj Title/Notes Editor

   Example 3
   Use  of Rule-Based Pump Controls
   and  Dry Weather Flow  Patterns
      Use title line as header for printing
! OK

Cancel
The Title/Notes editor is invoked when a project's Title/Notes data category is selected for editing.
As shown below, the editor contains a multi-line edit field where a description of a project can be
entered.  It also contains a check box used to indicate whether or not the first line of notes should
be used as a header for printing.
                                            263

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C.21   Transect Editor
 Transect Editor

   Transect Name
    92
Description

1
2
3
4
5
6
7
8
9
10
11
12
13
Station
[ft)
o
55
60
95
115
160







Elevation
(ft)
5
45
0
2
4
6







A












T-
                                      Modifiers:

                                       Stations

                                       Elevations

                                       Meander
The Transect Editor is  invoked when a new transect object is created or an existing transect is
selected for editing. It contains the following data entry fields:

Name
The name assigned to the transect.

Description
An optional comment or description of the transect.

Station/Elevation Data Grid
Values of distance from the left side of the channel along with the corresponding elevation of the
channel bottom as one moves across the channel from  left to right, looking in the downstream
direction. Up to 1500 data values can be entered.

Roughness
Values of Manning's roughness for the left overbank, right overbank, and main channel portion of
the transect. The overbank roughness values can be zero if no overbank exists.
                                           264

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Bank Stations
The distance values appearing in the Station/Elevation grid that mark the end of the left overbank
and the start of the right overbank. Use 0 to denote the absence of an overbank.

Modifiers
•   The Stations modifier is a factor by which the distance between each station will be multiplied
    when the transect data is processed by SWMM. Use a value of 0 if no such factor is needed.
•   The Elevations modifier is a constant value that will be added to each elevation value.
•   The Meander modifier is the ratio of the length of a meandering main channel to the length of
    the overbank area that surrounds  it. This modifier is  applied to  all conduits that use this
    particular transect  for their cross section. It assumes that the  length supplied for these
    conduits is that of the longer main channel. SWMM will  use the shorter overbank length in  its
    calculations while increasing the main channel roughness to account  for its longer length.
    The modifier is ignored if it is left blank or set to 0.

Right-clicking over the Data Grid  will make a popup Edit menu appear. It contains commands to
cut, copy, insert, and paste selected cells in the grid as well as options to insert or delete a row.

Clicking the View button  will  bring up a window  that illustrates the shape  of the transect cross
section.
                                           265

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C.22   Treatment Editor
 Treatment Editor for Node 10
Pollutant
TSS
Lead

Treatment Expression
C = 0.523*TSSA0.5*FlowA1.2


Treatment expressions have the general form: *
R = f (P, R_P, V)
or
C = f {P, R_P, V)
where:
R = fractional




remcval,


-


C = outlet concentration,
F = one or more pollutant names,
R P = one or more pollutant removals
{prepend R_ to pollutant name), •*•
                                       OK
The Treatment Editor is invoked whenever the Treatment property of a node is selected from the
Property Editor. It displays a list of the project's pollutants with an edit box next to each as shown
below. Enter a valid treatment expression in the box next to each  pollutant  which receives
treatment.

A treatment function can be any well-formed mathematical expression involving:
    •   the pollutant concentration (use the pollutant name to represent its concentration) - for
       non-storage nodes this is the mixture concentration of all flow streams entering the node
       while for storage nodes it is the pollutant concentration within the node's stored volume
    •   the removals of other pollutants  (use R_ prefixed to the pollutant name to represent
       removal)
    •   any of the following process variables:
       - FLOW for flow rate into  node (in user-defined flow units)

       - DEPTH for water depth above node invert (ft or m)

       - AREA for node surface area (ft2 or m2)

       - DT for routing time step (sec)

       - HRT for hydraulic residence time  (hours)

Any of the following math functions (which  are  case insensitive) can  be  used in  a treatment
expression:
                                           266

-------
    abs(x) for absolute value of x
    sgn(x) which is +1 for x >= 0 or -1 otherwise
    step(x) which is 0 forx <= 0 and  1 otherwise
    sqrt(x) for the square root of x
    log(x) for logarithm base e of x
    Iog10(x) for logarithm base 10 of x
    exp(x) for e raised to the x power
    the standard trig functions (sin, cos, tan, and cot)
    the inverse trig functions (asin, acos,  atan, and acot)
    the hyperbolic trig functions (sinh, cosh, tanh, and coth)
along with  the standard operators  +, -,  *, /, A  (for exponentiation ) and  any level  of  nested
parentheses.
                                            267

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C.23 Unit Hydrograph Editor
Un
it Hydrograph Editor
Mame of UH Group
^ain Gage Used
Hydrographs For:
Unit
Hydrographs I
Response
Short-Term
Medium -Term
Long -Term
R =
T =
K =
Vlont

UH1
Gagel



All Months





nitial Abstraction Depth
R
0.20
0.10
0.06
T
2
e
12






1^1

T


T
K
2
2
2 !
fraction of rainfall that becomes I&I
time to hydrograph peak (hours)
falling limb duration / rising limb duration
is with UH data have a (*] next to
OK

Cancel


them.

Help




The Unit Hydrograph Editor is invoked whenever a new unit hydrograph object is created or an
existing one is selected for editing. It is used to specify the shape parameters and rain gage for a
group of triangular unit hydrographs. These hydrographs are used to compute rainfall-dependent
infiltration/inflow (RDM) flow at selected nodes of the drainage system. A UH group can contain up
to 12 sets of unit hydrographs (one for each month of the year), and  each set can consist of up to
3  individual   hydrographs  (for  short-term,  intermediate-term,   and  long-term  responses,
respectively)  as  well as parameters  that describe  any initial abstraction  losses. The editor
contains the following data entry fields:

Name of UH Group
Enter the name assigned to the UH Group.

Rain Gage Used
Type in (or select from the dropdown list) the name of the rain gage that supplies rainfall data to
the unit hydrographs in the group.
                                          268

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Hydrographs For:
Select a month from the dropdown list box for which  hydrograph parameters will be defined.
Select All Months to specify a default set of hydrographs that apply to all months of the year.
Then  select specific months that need to have special hydrographs defined. Months listed with a
(*) next to them have had hydrographs assigned to them.

Unit Hydrographs
Select this tab to  provide the  R-T-K shape  parameters for each set of unit hydrographs  in
selected months of the year. The first row is used to specify parameters for a short-term response
hydrograph (i.e., small value of T), the second for a medium-term response hydrograph, and the
third for a long-term response hydrograph (largest value of T). It is not required  that all three
hydrographs be defined and the sum of the three R-values  do not have to equal 1. The shape
parameters for each UH consist of:
    •    R: the fraction of rainfall  volume that enters the sewer system
    •    7: the time from the onset of rainfall to the peak of the UH in hours
    •    K: the ratio of time to recession of the UH to the time  to peak

Initial Abstraction Depth
Select this tab  to provide parameters that describe how rainfall will be reduced  by any initial
abstraction depth available (i.e., interception and  depression storage)  before it  is processed
through the unit hydrographs defined for a specific month of the year. Different initial abstraction
parameters can be assigned to each of the three unit hydrograph responses. These parameters
are:
    •    D/nax: the maximum depth of initial abstraction available (in rain depth units)
    •    Dree: the rate  at which any utilized  initial  abstraction  is made available  again  (in rain
        depth units per day)
    •    Do: the amount of initial abstraction that has already been utilized  at the start of the
        simulation (in rain depth  units).

If a grid cell is left empty its corresponding parameter value is assumed to  be 0.  Right-clicking
over a data entry grid will make a popup Edit  menu appear.  It contains commands to cut, copy,
and paste text to or from selected cells in the grid.
                                           269

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                  APPENDIX D - COMMAND LINE SWMM
D.1
General Instructions
EPA SWMM can also be run  as  a  console application from the command line within a DOS
window. In this case the study area data are placed into a text file and results are written to a text
file. The command line for running SWMM in this fashion is:

    swmmS  inpfile rptfile outfile

where inpfile is the name of the input file, rptfile is the name of the output report file, and
outfile is the name of an optional binary output file. The latter stores all time series results in a
special binary format that will require a separate post-processor program for viewing. If no binary
output file name is supplied then all time series results will appear in the report file. As written, the
above command assumes that you  are working in the directory in which EPA  SWMM was
installed or that this directory has  been  added  to the PATH variable in your user profile  (or the
autoexec.bat file  in older versions of Windows).  Otherwise full  pathnames for the executable
swmm5.exe and the files on the command line must be used.
D.2    Input File Format

The input file for command  line  SWMM has the  same format as the project file  used by the
Windows version of the  program. Figure D-1  illustrates an example SWMM 5 input file. It is
organized in sections, where each section  begins with a  keyword enclosed in brackets. The
various keywords are listed below.
        [TITLE]
        [OPTIONS]
        [REPORT]
        [FILES]


        [RAINGAGES]
        [EVAPORATION]
        [TEMPERATURE]
        [ADJUSTMENTS]


        [SUBCATCHMENTS]
        [SUBAREAS]
        [INFILTRATION]


        [LID_CONTROLS]
        [LID USAGE]
                     project title
                     analysis options
                     output reporting instructions
                     interface file options

                     rain gage information
                     evaporation data
                     air temperature and snow melt data
                     monthly adjustments applied to climate variables

                     basic subcatchment information
                     subcatchment impervious/pervious sub-area data
                     subcatchment infiltration parameters

                     low impact development control information
                     assignment of LID controls to subcatchments
                                         270

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[AQUIFERS]
[GROUNDWATER]
[GWF]
[SNOWPACKS]


[JUNCTIONS]
[OUTFALLS]
[DIVIDERS]
[STORAGE]


[CONDUITS]
[PUMPS]
[ORIFICES]
[WEIRS]
[OUTLETS]


[XSECTIONS]
[TRANSECTS]
[LOSSES]
[CONTROLS]


[POLLUTANTS]
[LANDUSES]
[COVERAGES]
[LOADINGS]
[BUILDUP]
[WASHOFF]
[TREATMENT]


[INFLOWS]
[DWF]
[RDII]
[HYDROGRAPHS]


[CURVES]
[TIMESERIES]
[PATTERNS]
groundwater aquifer parameters
subcatchment groundwater parameters
groundwater flow expressions
subcatchment snow pack parameters

junction node information
outfall node information
flow divider node information
storage node information

conduit link information
pump link information
orifice link information
weir link information
outlet link information

conduit, orifice, and weir cross-section geometry
transect geometry for conduits with irregular cross-sections
conduit entrance/exit losses and flap valves
rules that control pump and regulator operation

pollutant information
land use categories
assignment of land  uses to subcatchments
initial pollutant loads on  subcatchments
buildup functions for pollutants and land uses
washoff functions for pollutants and land uses
pollutant removal functions at conveyance system nodes

external hydrograph/pollutograph inflow at nodes
baseline dry weather sanitary inflow at nodes
rainfall-dependent I/I information at nodes
unit hydrograph  data used to construct RDII inflows

x-y tabular data  referenced  in other sections
time series data referenced in other sections
periodic multipliers referenced in other sections
                                  271

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[TITLE]
Example SWMM Project
[OPTIONS]
FLOWJJNITS
INFILTRATION
FLOW_ROUTING
START_DATE
START_TIME
END_TIME
WET_STEP
DRY_STEP
ROUTING STEP
CFS
GREEN_AMPT
KINWAVE
8/6/2002
10:00
18:00
00:15:00
01:00:00
00:05:00
[RAINGAGES]
;;Name     Format      Interval   SCF  DataSource  SourceName
r r
GAGE1      INTENSITY   0:15       1.0  TIMESERIES  SERIES1

[EVAPORATION]
CONSTANT   0.02

[SUBCATCHMENTS]
;;Name  Raingage Outlet  Area    %Imperv   Width  Slope
r r
AREA1   GAGE1    NODE1   2       80.0      800.0  1.0
AREA2   GAGE1    NODE2   2       75.0      50.0   1.0

[SUBAREAS]
;;Subcatch  N_Imp  N_Perv   S_Imp  S_Perv  %ZER  RouteTo
r r
AREA1       0.2    0.02      0.02    0.1     20.0  OUTLET
AREA2       0.2    0.02      0.02    0.1     20.0  OUTLET

[INFILTRATION]
;;Subcatch   Suction   Conduct    InitDef
r r
AREA1        4.0       1.0        0.34
AREA2        4.0       1.0        0.34

[JUNCTIONS]
;;Name     Elev
r r
NODE1      10.0
NODE2      10.0
NODES      5.0
NODE4      5.0
NODE6      1.0
NODE?      2 . 0


                    Figure D-1 Example SWMM project file
                                  272

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[DIVIDERS]
;;Name Elev Link Type
r r

Parameters




NODES 3.0 C6 CUTOFF 1.0
[CONDUITS]
;;Name Nodel Node2
r r
Cl NODE1 NODES
C2 NODE2 NODE4
C3 NODES NODES
C4 NODE4 NODES
C5 NODES NODE6
C6 NODES NODE?
[XSECTIONS]
; ;Link Type Gl
f f
Cl RECT OPEN 0.
C2 RECT OPEN 0.
C3 CIRCULAR 1.
C4 RECT OPEN 1.
C5 PARABOLIC 1.
C6 PARABOLIC 1.
[POLLUTANTS]
;;Name Units Cppt Cgw
r r
TSS MG/L 0 0
Lead UG/L 0 0
[LANDUSES]
RESIDENTIAL
UNDEVELOPED
[WASHOFF]
;;Landuse Pollutant
r r
RESIDENTIAL TSS
UNDEVELOPED TSS
[COVERAGES]
; ; Subcatch Landuse
r r
AREA1 RESIDENTIAL
AREA2 RESIDENTIAL
[TIMESERIES]
; Rainfall time series
SERIES1 0:0 0.1 0:
SERIES1 0:45 0.1 1:

Length N Zl Z2 QO

800 0.01 000
800 0.01 000
400 0.01 000
400 0.01 000
600 0.01 000
400 0.01 000

G2 G3 G4

510 0
510 0
000 0
0 1.0 0 0
5 2.0 0 0
5 2.0 0 0




















Cii Kd Snow CoPollut CoFract

0 0
0 0 NO TSS 0.20




Type Coeff Expon SweepEff

EMC 23.4 0 0
EMC 12.1 0 0

Pent Landuse Pent

80 UNDEVELOPED 20
55 UNDEVELOPED 45


15 1.0 0:30 0.5
00 0.0 2:00 0.0







BMPEff

0
0









Figure D-1 Example SWMM project file (continued from previous page).
                               273

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The sections can appear in  any arbitrary order in the input file, and not all sections must  be
present. Each section can contain one or more lines of data. Blank lines may appear anywhere in
the file. A semicolon (;) can be used to  indicate that what follows on the line is a comment, not
data. Data items can appear in any column of a line.  Observe how in Figure D-1 these features
were used to create a tabular appearance for the data, complete with column headings.

Section keywords can  appear in mixed lower and upper case, and only the first four characters
(plus the  open bracket) are used to distinguish one keyword from another (e.g., [DIVIDERS] and
[Divi] are equivalent). An option is available in the [OPTIONS] section to choose flow units from
among cubic feet per second (CFS), gallons per minute (GPM), million  gallons per day (MGD),
cubic meters per second (CMS), liters per second, (IPS), or million liters per day (MLD). If cubic
feet or gallons are chosen for flow units, then US units are used for all other quantities. If cubic
meters or liters are chosen, then  metric  units apply to all other quantities. The  default flow units
are CFS.

A detailed description of the data in each section of the  input file will now be given. Each section
description begins on a new page. When listing the format of a line of data, mandatory keywords
are shown in boldface while optional items appear in  parentheses. A list of keywords separated
by a slash (YES/NO) means that only one of the words should appear in the data line.
                                          274

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Section:    [TITLE]

Purpose:   Attaches a descriptive title to the problem being analyzed.

Format:    Any number of lines may be entered. The first line will be used as a page header in
           the output report.
                                          275

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Section:   [OPTIONS]
Purpose:   Provides values for various analysis options.
Format:    FLOW_UNITS
          INFILTRATION
          FLOW_ROUTING
          LINKJDFFSETS
          FORCE_MAIN_EQUATION
          IGNORE_RAINFALL
          IGNORE_SNOWMELT
          IGNORE_GROUNDWATER
          IGNORE_RDII
          IGNORE_ROUTING
          IGNORE_QUALITY
          ALLOW_PONDING
          SKIP_STEADY_STATE
          SYS_FLOW_TOL
          LAT_FLOW_TOL
          START_DATE
          START_TIME
          END_DATE
          END_TIME
          REPORT_START_DATE
          REPORT_START_TIME
          SWEEP_START
          SWEEP_END
          DRY_DAYS
          RE PORT_S TE P
          WET_STEP
          DRY_STEP
          ROUTING_STEP
          LENGTHENING_STEP
          VARIABLE_STEP
          MINIMUM_STEP
          INERTIAL_DAMPING
          NORMAL FLOW  LIMITED
CFS  /  GPM / MGD  /  CMS / LPS / MLD
HORTON / MODIFIED_HORTON / GREEN_AMPT
/ MODIFIED_GREEN_AMPT / CURVE_NUMBER
STEADY / KINWAVE / DYNWAVE
DEPTH  / ELEVATION
H-W  /  D-W
YES  /  NO
YES  /  NO
YES  /  NO
YES  /  NO
YES  /  NO
YES  /  NO
YES  /  NO
YES  /  NO
value
value
month/day/year
hours:minutes
month/day/year
hours:minutes
month/day/year
hours:minutes
month/day
month/day
days
hours:minutes:seconds
hours:minutes:seconds
hours:minutes:seconds
seconds
seconds
value
seconds
NONE / PARTIAL / FULL
SLOPE  / FROUDE / BOTH
                                      276

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          MIN_SURFAREA              value
          MIN_SLOPE                  value
          MAX_TRIALS                 value
          HEAD_TOLERANCE            value
          THREADS                    value
          TEMPDIR                    directory

Remarks: FLOW_UNITS makes a choice of flow units. Selecting a US flow unit means that all
          other quantities will be expressed in US units, while choosing a metric flow unit will
          force all quantities to be expressed in metric units. The default is CFS.

          INFILTRATION selects a model for computing infiltration of rainfall into the upper
          soil zone of subcatchments. The default model is HORTON.

          FLOW_ROUTING determines  which method is used  to  route  flows through the
          drainage system. STEADY refers to sequential  steady state routing (i.e. hydrograph
          translation), KINWAVE to kinematic wave routing, DYNWAVE to dynamic wave routing.
          The default routing method is KINWAVE.

          LINK_OFFSETS determines  the convention used to specify the position  of a link
          offset above  the invert of its  connecting node. DEPTH indicates that offsets are
          expressed  as the distance between the node invert and the link while ELEVATION
          indicates that the absolute elevation of the offset is used. The default is DEPTH.

          FORCE_MAIN_EQUATION  establishes whether the Hazen-Williams (H-W) or the
          Darcy-Weisbach  (D-W)  equation  will be  used  to compute  friction losses  for
          pressurized flow in conduits  that have been assigned a Circular Force  Main  cross-
          section shape. The default is  H-W.

          IGNORE_RAINFALL is set to  YES if all rainfall data and runoff calculations should be
          ignored. In  this  case SWMM  only performs flow and pollutant routing based on user-
          supplied direct and dry weather inflows. The default is NO.

          IGNORE_SNOWMELT is set to  YES if snowmelt calculations should be  ignored when a
          project file contains snow pack objects. The default is NO.

          IGNORE_GROUNDWATER is set to YES if groundwater calculations should be ignored
          when a project file contains aquifer objects. The default is NO.

          IGNORE_RDII  is set to YES  if rainfall  dependent inflow/infiltration should be ignored
          when RDM  unit hydrographs  and RDM inflows  have been supplied to a project file.
          The default is NO.
                                         277

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IGNORE_ROUTING is set to YES if only runoff should be computed even if the project
contains drainage system links and nodes. The default is NO.

IGNORE_QUALITY is set to YES if pollutant washoff, routing, and treatment should be
ignored in a project that has pollutants defined. The default is NO.

ALLOW_PONDING determines whether excess water is allowed to collect atop nodes
and be re-introduced into the system as conditions permit. The default is NO ponding.
In order for ponding to actually occur at a particular node, a non-zero value for its
Ponded Area attribute must be used.

SKIP_STEADY_STATE should be set to YES if flow routing computations should be
skipped during steady state  periods of a simulation during which  the last set of
computed flows will  be used. A time step is considered to be in steady state if the
percent difference between total system inflow and total system outflow is below the
SYS_FLOW_TOL and the percent difference between  current  and previous lateral
inflows are below the LAT_FLOW_TOL. The default for this option is NO.

SYS_FLOW_TOL is the  maximum percent difference between  total system inflow  and
total system outflow which can occur in order for the SKIP_STEADY_STATE option to
take effect. The default is 5 percent.

LAT_FLOW_TOL  is  the  maximum  percent difference between  the  current  and
previous  lateral inflow at all  nodes in the conveyance  system  in order  for  the
SKIP_STEADY_STATE option to take effect. The default is 5 percent.

START_DATE is the date when the simulation  begins. If not supplied, a date of
1/1/2002  is used.

START_TIME is the time  of day on the starting date when the simulation begins. The
default is 12 midnight (0:00:00).

END_DATE is the date when the simulation is to end. The default is the start date.

END_TIME is  the time  of day on the ending date when the simulation will end. The
default is 24:00:00.

REPORT_START_DATE is the date when reporting of results is to begin. The default is
the simulation start date.

REPORT_START_TIME is the time of day on the report starting date when reporting is
to begin. The default is the simulation start time of day.

SWEEP_START is the day of the year (month/day) when street sweeping operations
begin. The default is 1/1.
                               278

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SWEEP_END is the day of the year (month/day) when street sweeping operations end.
The default is 12/31.

DRY_DAYS  is the number of days with no rainfall prior to the start of the simulation.
The default is 0.

REPORT_STEP is the time interval for reporting  of computed  results. The default is
0:15:00.

WET_STEP  is the time step length  used to compute  runoff from subcatchments
during  periods of rainfall  or when ponded water still remains on the surface. The
default is 0:05:00.

DRY_STEP  is the time step length used for runoff computations (consisting essentially
of pollutant buildup) during periods when there  is no rainfall and no ponded water.
The default is 1:00:00.

ROUTING_STEP is the time step length in seconds used for routing flows and water
quality constituents  through  the  conveyance system.  The default is 600 sec  (5
minutes) which should be reduced if using dynamic wave routing. Fractional values
(e.g., 2.5) are permissible as are values entered in hours:minutes:seconds format.

LENGTHENING_STEP is a time step, in seconds, used to  lengthen conduits under
dynamic wave routing, so that they meet the Courant stability criterion under full-flow
conditions (i.e., the travel time of a wave will not be smaller than the specified conduit
lengthening  time  step).  As  this  value  is decreased,  fewer conduits will require
lengthening. A value of 0 (the default) means that no conduits will be lengthened.

VARIABLE_STEP  is  a safety  factor applied to a variable time  step  computed for
each time  period under  dynamic wave flow routing.  The  variable time step  is
computed so as to satisfy the Courant stability criterion for each conduit and yet not
exceed  the ROUTING_STEP  value. If the safety factor is  0  (the default), then no
variable time step is used.

MINIMUM_STEP is the smallest  time step allowed when variable time steps are used
for dynamic wave flow routing. The default value  is 0.5 seconds.

INERTIAL_DAMPING   indicates  how the  inertial   terms  in  the  Saint  Venant
momentum equation  will  be  handled under  dynamic wave flow routing. Choosing
NONE maintains  these terms  at  their  full  value under all  conditions. Selecting
PARTIAL will reduce the terms as flow comes  closer to being critical (and ignores
them when  flow is supercritical). Choosing FULL will drop the terms altogether.

NORMAL_FLOW_LIMITED  specifies which condition is checked to determine if flow in
a conduit is supercritical and should thus be limited to the normal flow. Use SLOPE to
check if the water surface slope is greater than the conduit slope, FROUDE to check if
                               279

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the Froude number is greater than 1.0, or BOTH to check both conditions. The default
is BOTH.

MIN_SURFAREA is a minimum surface area used at nodes when computing changes
in water depth under dynamic wave routing. If 0 is entered, then the default value of
12.566 ft2 (i.e., the area of a 4-ft diameter manhole) is used.

MIN_SLOPE  is the minimum value allowed for a conduit's slope (%).  If zero (the
default) then no minimum  is  imposed  (although SWMM uses  a  lower limit on
elevation drop of 0.001 ft (0.00035 m) when computing a conduit slope).

MAX_TRIALS is the maximum  number of trials allowed during a time step to reach
convergence when  updating  hydraulic heads at the conveyance system's nodes. The
default value is 8.

HEAD_TOLERANCE  is the difference  in  computed head  at each  node  between
successive trials below which the flow solution for the current time step is assumed to
have converged. The default tolerance is 0.005 ft (0.0015 m).

THREADS is the number of parallel computing threads to use for dynamic wave flow
routing on  machines equipped with multi-core processors. The default is 1.

TEMPDIR provides  the name of  a file directory (or folder) where SWMM writes  its
temporary files. If the directory  name contains spaces then it should be placed within
double quotes.  If no directory is specified, then the temporary files are written to the
current directory that the user is working in.
                               280

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Section:   [REPORT]

Purpose:  Describes the contents of the report file that is produced.

Formats:  INPUT            YES /  NO
          CONTINUITY      YES /  NO
          FLOWSTATS       YES /  NO
          CONTROLS         YES /  NO
          SUBCATCHMENTS   ALL /  NONE  / 
          NODES            ALL /  NONE  / 
          LINKS            ALL /  NONE  / 
          LID              Name   Subcatch  Fname

Remarks:  INPUT specifies whether or not a  summary of the input data should be provided in
          the output report. The default is NO.

          CONTINUITY specifies whether continuity checks should be reported or not. The
          default is YES.

          FLOWSTATS specifies whether summary flow statistics should be reported or not. The
          default is YES.

          CONTROLS  specifies whether all control actions taken during a simulation should be
          listed or not. The default is NO.

          SUBCATCHMENTS gives a list of subcatchments whose results are to be reported. The
          default is NONE.

          NODES gives a list of nodes whose  results are to be reported. The default is NONE.

          LINKS gives a list of links whose results are to  be reported. The default is NONE.

          LID specifies that the LID control  Name in subcatchment Subcatch should have a
          detailed performance report for it written to file Fname.

          The SUBCATCHMENTS, NODES, LINKS, and  LID lines  can  be repeated multiple
          times.
                                        281

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Section:   [FILES]

Purpose:  Identifies optional interface files used or saved by a run.

Formats:  USE / SAVE  RAINFALL     Fname
          USE / SAVE  RUNOFF       Fname
          USE / SAVE  HOTSTART     Fname
          USE / SAVE  RDII         Fname
          USE   INFLOWS             Fname
          SAVE  OUTFLOWS            Fname

Remarks:  Fname  is the name of an interface file.

Refer to Section 11.7   Interface Files for a description  of interface files. Rainfall, Runoff, and
RDII files can either be used or saved in a run, but not both. A run can both use and save a Hot
Start file (with different names).
                                        282

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Section:    [RAINGAGES]

Purpose:   Identifies each rain gage that provides rainfall data for the study area.

Formats:   Name  Form  Intvl  SCF TIMESERIES Tseries
           Name  Form  Intvl  SCF FILE Fname Sta Units

Remarks:   Name      name assigned to rain gage.
           Form      form of recorded rainfall, either INTENSITY , VOLUME or CUMULATIVE.
           Intvl     time interval between gage readings in decimal hours or hours:minutes
                     format (e.g., 0:15 for 15-minute readings).
           SCF       snow catch deficiency correction factor (use 1.0 for no adjustment).
           Tseries  name of time series in [TIMESERIES] section with rainfall data.
           Fname     name of external file with rainfall data. Rainfall files are discussed in
                     Section 11.3    Rainfall Files.
           sta       name of recording station used in the rain file.
           Units     rain depth units  used in the rain file, either IN (inches) or MM
                     (millimeters).
                                         283

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Section:    [EVAPORATION]

Purpose:   Specifies how daily evaporation rates vary with time for the study area.

Formats:   CONSTANT     evap
           MONTHLY       el e2  e3 e4  e5  e6 e7 e8  e9 elO ell  e!2
           TIMESERIES   Tseries
           TEMPERATURE
           FILE          (pi p2 p3 p4 p5 p6 p7 p8 p9 plO pll p!2)
           RECOVERY    pat tern ID
           DRY ONLY    NO / YES
Remarks:  evap
           el
constant evaporation rate (in/day or mm/day).
evaporation rate in January (in/day or mm/day).
           e!2       evaporation rate in December (in/day or mm/day).
           Tseries  name of time series in [TIMESERIES] section with evaporation data.
           pi        pan coefficient for January.

           p!2       pan coefficient for December.
           pat ID     name of a monthly time pattern.

           Use  only  one of the above formats (CONSTANT,   MONTHLY,   TIMESERIES,
           TEMPERATURE, or FILE).  If no [EVAPORATION] section appears, then evaporation is
           assumed to be 0.

           TEMPERATURE indicates that evaporation rates will  be computed from the daily air
           temperatures contained in an  external  climate file whose name is provided in the
           [TEMPERATURE] section (see below). This method also uses the site's latitude, which
           can also be specified in the [TEMPERATURE] section.

           FILE indicates that evaporation data will be  read directly  from the same external
           climate file used for air  temperatures as specified  in the [TEMPERATURE] section
           (see below).

           RECOVERY identifies  an optional monthly time pattern of multipliers used to modify
           infiltration recovery rates  during dry periods. For example, if the normal infiltration
           recovery rate was 1% during a specific time period and a  pattern factor of 0.8 applied
           to this period, then the actual recovery rate would be  0.8%.

           DRY_ONLY determines if evaporation only occurs during periods with no precipitation.
           The default is NO.
                                         284

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Section:    [TEMPERATURE]

Purpose:   Specifies  daily air  temperatures,  monthly wind  speed,  and  various snowmelt
           parameters for the study area. Required only when snowmelt is being modeled or
           when evaporation rates are computed from daily temperatures or are read from an
           external climate file.

Formats:   TIMESERIES  Tseries
           FILE   Fname  (Start)
           WINDSPEED   MONTHLY  si s2  s3 s4  s5 s6  s7 s8 s9 slO  sll s!2
           WINDSPEED   FILE
           SNOWMELT            Stemp  ATIwt   RNM  Elev  Lat  DTLong
           ADC IMPERVIOUS     f.O f.l  f.2 f.3 f.4  f.5 f. 6 f. 7  f.8 f.9
           ADC PERVIOUS        f.O f.l  f.2 f.3 f.4  f.5 f.6 f.l  f.8 f.9
Remarks:   Tseries   name of time series in [TIMESERIES] section with temperature data.
           Fname     name of external Climate file with temperature data.
           start     date to begin reading from the file in month/day/year format (default is
           si
the beginning of the file).
average wind speed in January (mph or km/hr).
           s!2       average wind speed in December (mph or km/hr).
           stemp     air temperature at which precipitation falls as snow (deg F or C).
           ATiwt     antecedent temperature index weight (default is 0.5).
           RNM       negative melt ratio (default is 0.6).
           Elev      average elevation of study area above mean sea level (ft or m) (default is
                     0).
           Lat       latitude of the study area in degrees North (default is 50).
           DTLong    correction, in minutes of time, between true solar time and the standard
                     clock time (default is 0).
           f. o       fraction of area covered by snow when ratio of snow depth to depth at
                     100% cover is 0

           f. 9       fraction of area covered by snow when ratio of snow depth to depth at
                     100% cover is 0.9.

           Use the TIMESERIES line  to read air temperature from a time series or the FILE line
           to read it from an external Climate file. Climate files are discussed in  Section 11.4
              Climate Files. If neither format is used, then air temperature remains constant at
           70 degrees F.
                                        285

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Wind  speed can be  specified either  by  monthly average values  or  by  the same
Climate file used for air temperature.  If neither option appears, then wind speed is
assumed to be 0.

Separate Areal Depletion Curves (ADC) can be defined for impervious and pervious
sub-areas. The ADC parameters will default to 1.0 (meaning no depletion) if no data
are supplied for a particular type of sub-area.
                               286

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Section:    [ADJUSTMENTS]

Purpose:   Specifies optional monthly adjustments to be made to temperature, evaporation rate,
           rainfall intensity and hydraulic conductivity in each time period of a simulation.
Format:
           TEMPERATURE
           EVAPORATION
           RAINFALL
           CONDUCTIVITY
       tl  t2 t3 t4  t5 t6  t7 t8  t9 tlO  til  t!2
       el  e2 e3 e4  e5 e6  el e8  e9 elO  ell  e!2
       rl  r2 r3 r4  r5 r6  rl r8  r9 rlO  rll  r!2
       cl  c2 c3 c4  c5 c6  c7 c8  c9 clO  ell  c!2
Remarks: tl. . tl2

           el..e!2

           rl..r!2
           cl..c!2
adjustments to temperature in January, February, etc., as plus or minus
degrees F (degrees C).
adjustments to evaporation rate in January, February, etc., as plus or
minus in/day (mm/day).
multipliers applied to precipitation rate in January, February, etc.
multipliers applied to soil hydraulic conductivity in January, February, etc.
used in either Morton or Green-Ampt infiltration.
The same adjustment is applied for each time period within a given month and is repeated for that
month in each subsequent year being simulated.
                                         287

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Section:   [SUBCATCHMENTS]

Purpose:  Identifies each subcatchment within the study area.  Subcatchments are land area
          units which generate runoff from rainfall.

Format:   Name Rgage OutID  Area  %Imperv Width Slope  Clength  (Spack)
Remarks:  Name
          Rgage
          OutID
          Area
          name assigned to subcatchment.
          name of rain gage in [RAINGAGES] section assigned to subcatchment.
          name of node or subcatchment that receives runoff from subcatchment.
          area of subcatchment (acres or hectares).
%imperv  percent imperviousness of subcatchment.
width     characteristic width of subcatchment (ft or meters).
slope     subcatchment slope (percent).
ciength  total curb length (any length units). Use 0 if not applicable.
Spack     optional name of snow pack object (from  [SNOWPACKS] section) that
          characterizes snow accumulation and melting over the subcatchment.
                                        288

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Section:    [SUBAREAS]

Purpose:   Supplies information about pervious and impervious  areas for each subcatchment.
           Each subcatchment can consist of a pervious sub-area, an impervious sub-area with
           depression storage, and an impervious sub-area without depression storage.

Format:    Subcat  Nimp  Nperv  Simp Sperv  %Zero RouteTo (%Routed)
Remarks:   Subcat
           Nimp
           Nperv
           Simp
           Sperv
           %Zero
          subcatchment name.
          Manning's n for overland flow over the impervious sub-area.
          Manning's n for overland flow over the pervious sub-area.
          depression storage for impervious sub-area (inches or mm).
          depression storage for pervious sub-area (inches or mm).
          percent of impervious area with no depression storage.
RouteTo  IMPERVIOUS if pervious area runoff runs onto impervious area,
          PERVIOUS if impervious runoff runs onto pervious area, or OUTLET if
          both areas drain to the subcatchment's outlet (default = OUTLET).
%Routed  percent of runoff routed from one type of area to another (default = 100).
                                         289

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Section:    [INFILTRATION]

Purpose:   Supplies infiltration parameters for each subcatchment. Rainfall lost to infiltration only
           occurs over the pervious sub-area of a subcatchment.

Formats:   Subcat  MaxRate   MinRate   Decay  DryTime   Maxlnf
           Subcat  Psi  Ksat   IMD
           Subcat  CurveNo   Ksat  DryTime

Remarks:  Subcat   subcatchment name.

           For Morton and Modified Morton Infiltration:
           MaxRate  maximum infiltration rate on Morton curve (in/hr or mm/hr).
           MinRate  minimum infiltration rate on Morton curve (in/hr or mm/hr).
           Decay     decay rate constant of Morton curve (1/hr).
           DryTime  time it takes for fully saturated soil to dry (days).
           Maxinf   maximum infiltration volume possible (0 if not applicable) (in or mm).

           For Green-Ampt and Modified Green-Ampt Infiltration:
           Psi       soil capillary suction (in or mm).
           Ksa t      soil saturated hydraulic conductivity (in/hr or mm/hr).
           IMD       initial soil moisture deficit (volume of voids / total volume).

           For Curve-Number Infiltration:
           CurveNo  SCS Curve Number.
           Ksa t      soil saturated hydraulic conductivity (in/hr or mm/hr)
                     (This property has been deprecated and is no longer used.)
           DryTime  time it takes for fully saturated soil to dry (days).
                                         290

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Section:    [LID_CONTROLS]

Purpose:   Defines scale-independent LID controls that can be deployed within subcatchments.

Formats:   Name   Type

           followed by one or more of the following lines depending on Type:

           Name  SURFACE  StorHt   VegFrac  Rough  Slope  Xslope
           Name  SOIL      Thick  For  FC   WP  Ksat  Kcoeff  Suet
           Name  PAVEMENT Thick  Vratio   Fraclmp  Perm  Vclog
           Name  STORAGE  Height   Vratio   Seepage   Vclog
           Name  DRAIN     Coeff  Expon  Offset   Delay
           Name  DRAINMAT Thick  Vratio   Rough
Remarks:  Name
           Type
name assigned to LID process.
BC for bio-retention cell; RG for rain garden; GR for green roof; IT for
infiltration trench; PP for permeable pavement; RB for rain barrel; RD for
rooftop disconnection; vs for vegetative swale.
           For LIDs with Surface Layers:
           storHt   when confining walls or berms are present this is the maximum depth to
                     which water can pond above the surface of the unit before overflow
                     occurs (in inches or mm). For LIDs that experience overland flow it is the
                     height of any surface depression storage. For swales, it is the height of
                     its trapezoidal cross section.
           VegFrac  fraction of the surface storage volume that is filled with vegetation.
           Rough     Manning's n for overland flow over surface soil cover, pavement, roof
                     surface or a vegetative swale. Use 0 for other types of LIDs.
           slope      slope of a roof surface, pavement surface or vegetative swale (percent).
                     Use 0 for other types of LIDs.
           Xslope   slope (run over rise) of the side walls of a vegetative swale's cross
                     section.  Use 0 for other types of LIDs.

           If either Rough or slope values are  0 then any ponded water that exceeds the
           surface storage depth is  assumed to completely overflow the LID control within  a
           single time step.

           For LIDs with Pavement Layers:
           Thick     thickness of the pavement layer (inches or mm).
           Vratio   void ratio (volume of void space relative to the volume of solids  in the
                     pavement for continuous systems or for the fill material used in modular
                     systems). Note that porosity = void ratio / (1 + void ratio).
                                         291

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Fracimp   ratio of impervious paver material to total area for modular systems; 0 for
           continuous porous pavement systems.
Perm      permeability of the concrete or asphalt used in continuous systems or
           hydraulic conductivity of the fill material (gravel or sand) used in modular
           systems (in/hr or mm/hr).
vdog     number of pavement layer void volumes of runoff treated it takes to
           completely clog the pavement. Use a value of 0 to ignore clogging.

For LIDs with Soil  Layers:
Thick     thickness of the soil layer (inches or mm).
For       soil porosity (volume of pore space relative to total volume).
FC         soil field capacity (volume of pore water relative to total volume after the
           soil has been allowed to drain fully).
WP         soil wilting point (volume of pore water relative to total volume for a well
           dried soil where only bound water remains).
Ksa t      soil's saturated hydraulic conductivity (in/hr or mm/hr).
Kcoeff   slope  of the curve of log(conductivity) versus soil moisture content
           (dimensionless).
Suet      soil capillary suction (in or mm).

For LIDs with Storage Layers:
Height    thickness of the storage layer or height of a rain barrel (inches or mm).
Vratio    void ratio (volume of void space relative to the volume of solids in the
           layer). Note that porosity = void ratio / (1 + void ratio).
Seepage   the rate at which water seeps from the layer into the underlying native
           soil when first constructed (in/hr or mm/hr). If there is an impermeable
           floor or liner below the layer then use a value of 0.
vdog     number of storage layer void volumes of runoff treated it takes to
           completely clog the layer. Use a value of 0 to ignore clogging.
Values for Vratio, Seepage, and vdog are ignored for rain barrels.

For LIDs with Drain Systems:
Coeff     coefficient C that determines the rate of flow through the drain as a
           function of height of stored water above the drain bottom. For Rooftop
           Disconnection it is the maximum flow rate (in inches/hour or mm/hour)
           that the roofs gutters and downspouts can handle before overflowing.
Expon     exponent n that determines the rate of flow through the drain as a
           function of height of stored water above the drain outlet.
offset    height of the drain line above the bottom of the storage layer or rain
           barrel (inches or mm).
                               292

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           Delay     number of dry weather hours that must elapse before the drain line in a
                     rain barrel is opened (the line is assumed to be closed once rainfall
                     begins). A value of 0 signifies that the barrel's drain line is always open
                     and drains continuously.  This parameter is ignored for other types of
                     LIDs.

           For Green Roof LIDs with Drainage Mats:
           Thick    thickness of the drainage mat (inches or mm).
           Vratio    ratio of void volume to total volume in the mat.
           Rough    Manning's n constant used to compute the horizontal flow rate of drained
                     water through the mat.

The following table shows which  layers are required (x) or are optional (o) for each type of LID
process:
LID Type
Bio-Retention Cell
Rain Garden
Green Roof
Infiltration Trench
Permeable
Pavement
Rain Barrel
Rooftop
Disconnection
Vegetative Swale
Surface
X
X
X
X
X

X
X
Pavement




X



Soil
X
X
X

0



Storage
X


X
X
X


Drain
0


0
0
X
X

Drain Mat


X





The equation used to compute flow rate out of the underdrain per unit area of the LID (in in/hr or
mm/hr) is q = C(h-Hd)n where q is outflow, h is height of stored water (inches or mm) and Hd
is the drain offset height. Note that the units of C depend on the unit system being used as well
as the value assigned to n.

The actual dimensions of an LID  control are provided in the  [LIDJJSAGE] section when it is
placed in a particular subcatchment.

Examples:  ;A street  planter with  no drain
           Planter  BC
           Planter  SURFACE    6   0.3  0     0       0
           Planter  SOIL      24   0.5  0.1  0.05   1.2  2.4
           Planter  STORAGE   12   0.5  0.5  0
                                         293

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;A green roof with impermeable bottom
GR1  BC
GR1  SURFACE  3000     0
GR1  SOIL     3  0.5  0.1  0.05  1.2  2.4
GR1  STORAGE  3  0.5  0    0
GR1  DRAIN    5  0.5  0    0

;A rain barrel that drains 6 hours after rainfall ends
RB12  RB
RB12  STORAGE  36  0    00
RB12  DRAIN    10  0.5  0  6

;A grass swale 24 in. high with 5:1 side slope
Swale  VS
Swale  SURFACE  24  0  0.2  3  5
                          294

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Section:   [LID_USAGE]

Purpose:   Deploys LID controls within specific subcatchment areas.

Format:    Subcat LID Number Area  Width InitSat  Fromlmp  ToPerv
                                                       (RptFile  DrainTo)

Remarks:  Subcat    name of the subcatchment using the LID process.
           LID       name of an LID process defined in the [LID_CONTROLS] section.
           Number    number of replicate LID units deployed.
           Area      area of each replicate unit (ft2 or m2).
           width     width of the outflow face of each identical LID unit (in  ft or m). This
                      parameter applies to roofs, pavement, trenches, and  swales that use
                      overland flow to convey surface runoff off of the unit. It can be set to 0 for
                      other LID processes, such as bio-retention cells, rain gardens, and rain
                      barrels that simply spill any excess captured runoff over their berms.
           initsat   for bio-retention cells, rain gardens, and green roofs this is the degree to
                      which  the  unit's  soil  is  initially filled with  water  (0  %  saturation
                      corresponds to the wilting point moisture content, 100 %  saturation has
                      the  moisture content equal  to the porosity). The storage  zone beneath
                      the soil zone of the cell is assumed to be completely dry. For other types
                      of LIDs it corresponds to the degree  to which their  storage zone is
                      initially filled with water
           Fromimp   percent of the impervious portion of the subcatchment's non-LID area
                      whose  runoff is treated by the LID practice. (E.g., if rain  barrels are used
                      to capture roof runoff and roofs represent 60% of the impervious area,
                      then the impervious area treated is 60%). If the LID unit  treats only direct
                      rainfall, such as with a green roof, then this value should be 0. If the LID
                      takes up the entire subcatchment then this field is ignored.
           ToPerv    a value of 1 indicates  that the surface  and drain flow from the LID unit
                      should  be routed back onto the pervious area  of the subcatchment that
                      contains it. This would be a common  choice to make for  rain  barrels,
                      rooftop disconnection, and possibly green roofs. The default value is 0.
           RptFile   optional name of a file to which detailed time series  results for the LID
                      will  be  written. Enclose the  name in  double quotes if it  contains spaces
                      and include the full path if it is different than the SWMM  input file path.
                      Use '*'  if not applicable and an entry for DrainTo follows
           DrainTo  optional  name of subcatchment or node  that receives flow  from the unit's
                      drain line, if different from the outlet of  the subcatchment  that the LID is
                      placed  in.

           If ToPerv is set to 1  and DrainTo set to some other outlet, then only the excess
           surface flow from the LID unit will be routed back to the  subcatchment's pervious
           area while the underdrain flow will be sent to DrainTo.
                                          295

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         More than one type of LID process can be deployed within a subcatchment as long
         as their total area does not exceed that of the subcatchment and the total percent
         impervious area treated does not exceed 100.

Examples: ;34  rain barrels  of  12  sq ft each are  placed in
         ;subcatchment SI. They  are initially empty and treat 17%
         ;of  the runoff  from  the subcatchment's  impervious area.
         ;The  outflow  from the barrels is returned to the
         ;subcatchment's pervious area.
         SI   RB14  34  12  0   0   17  1

         ;Subcatchment S2  consists entirely  of  a single vegetative
         ;swale  200 ft long by  50 ft wide.
         S2   Swale  1  10000   50  0  0  0  "swale.rpt"
                                     296

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Section:   [AQUIFERS]
Purpose:   Supplies  parameters for each unconfined groundwater aquifer in the study area.
           Aquifers consist of two zones - a lower saturated zone and  an upper unsaturated
           zone with a moving boundary between the two.

Formats:   Name For WP FC Ks  Kslp Tslp ETu ETs  Seep  Ebot  Egw  Umc  (Epat)

Remarks:  Name  name assigned to aquifer.
           Por   soil porosity (volumetric fraction).
           WP     soil wilting point (volumetric fraction).
           FC     soil field capacity (volumetric fraction).
           KS     saturated hydraulic conductivity (in/hr or mm/hr).
           Kslp  slope of the logarithm of hydraulic conductivity versus moisture deficit (i.e.,
                  porosity minus moisture content) curve (in/hr or mm/hr).
           Tslp  slope of soil tension versus moisture content curve (inches or mm).
           ETU   fraction of total evaporation available for evapotranspiration in the upper
                  unsaturated zone.
           ETS   maximum depth into the lower saturated zone over which evapotranspiration
                  can occur (ft or m).
           Seep  seepage rate from saturated zone to deep groundwater when water table is
                  at ground surface (in/hr or mm/hr).
           Ebot  elevation of the bottom of the aquifer (ft or m).
           Egw   groundwater table elevation at start of simulation (ft or m).
           Umc   unsaturated zone moisture content at start of simulation (volumetric fraction).
           Epa t  name of optional monthly time pattern used to adjust the upper zone
                  evaporation fraction for different  months of the year.

           Local values for Ebot, Egw, and Umc can be assigned to specific subcatchments in
           the  [GROUNDWATER]  section described below.
                                          297

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Section:   [GROUNDWATER]

Purpose:   Supplies parameters that determine the rate of groundwater flow between the aquifer
           underneath a subcatchment and a node of the conveyance system.

Format:
Subcat Aquifer Node  Esurf Al  Bl A2 B2 A3 Dsw (Egwt  Ebot  Egw  Umc)

Remarks:  Subcat   subcatchment name.
           Aquifer  name of groundwater aquifer underneath the subcatchment.
           Node      name of node in conveyance system exchanging groundwater with
                     aquifer.
           Esurf    surface elevation of subcatchment (ft or m).
           Al        groundwater flow coefficient (see below).
           Bl        groundwater flow exponent (see below).
           A2        surface water flow coefficient (see below).
           B2        surface water flow exponent (see below).
           A3        surface water - groundwater interaction coefficient (see below).
           DSW       fixed depth of surface water at receiving node (ft or m) (set to zero if
                     surface water depth will vary as computed by flow routing).
           Egwt      threshold groundwater table elevation which must be reached before any
                     flow occurs (ft or m). Leave blank (or enter *) to use the elevation of the
                     receiving node's invert.
           The following optional parameters can be used  to override the values supplied for the
           subcatchment's aquifer.
           Ebot   elevation of the bottom of the aquifer (ft or m).
           Egw    groundwater table elevation at the start of the simulation (ftorm).
           Umc    unsaturated zone moisture content at start of simulation (volumetric fraction).

The flow coefficients are used in the following equation that determines the lateral groundwater
flow rate based on groundwater and surface water elevations:
    QL = A1 (Hgw - Hcb) B1 - A2 (Hs« - Hcb) B2  + A3 Hgw Hsw
where:
QL  =   lateral groundwater flow (cfs per acre or cms per hectare),
Hgw  =  height of saturated zone above bottom of aquifer (ft or m),
Hsw  =  height of surface water at receiving node above aquifer bottom (ft or m),
Hcb  =  height of channel bottom above aquifer bottom (ft or m).
                                         298

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Section:    [GWF]
Purpose:   Defines custom groundwater flow equations for specific subcatchments.
Format:    subcat  LATERAL/DEEP
Remarks:  Subcat
           Expr
subcatchment name.
math formula expressing the rate of groundwater flow (in cfs per acre or
cms per hectare for lateral flow or in/hr or mm/hr for deep flow) as a
function of the following variables:
Hgw   (for height of the groundwater table)
HSW   (for height of the surface water)
Hcb   (for height of the channel bottom)
Hgs   (for height of ground surface)
       where all heights are relative to the aquifer bottom and have
       units of either feet or meters;
KS     (for saturated hydraulic conductivity in in/hr or mm/hr)
K      (for unsaturated hydraulic conductivity in in/hr or mm/hr)
Theta (for moisture content of unsaturated zone)
Phi   (for aquifer soil porosity)
Fi     (for infiltration rate from the ground surface in in/hr or mm/hr)
FU     (for percolation rate from the upper unsaturated zone in in/hr or
       mm/hr)
A      (for subcatchment area in acres or hectares)
           Use LATERAL to designate an expression for lateral groundwater flow (to a node of
           the conveyance network) and DEEP for vertical loss to deep groundwater.

           See the [TREATMENT]  section for a list of built-in math functions that can be used in
           Expr. In particular, the STEP (x)  function is 1 when x  >  o and is 0 otherwise.

Examples: ;Two-stage  linear  reservoir  for lateral  flow
           Subcatchl LATERAL  0.001*Hgw  +  0.05*(Hgw-5)*STEP(Hgw-5)

           ;Constant seepage  rate to deep aquifer
           Subactchl   DEEP   0.002
                                         299

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Section:   [SNOWPACKS]

Purpose:  Specifies parameters that  govern  how snowfall  accumulates  and melts on the
          plowable, impervious and pervious surfaces of subcatchments.

Formats:  Name PLOWABLE    Cmin   Cmax   Tbase   FWF  SDO  FWO   SNNO
          Name IMPERVIOUS  Cmin   Cmax   Tbase   FWF  SDO  FWO   SD100
          Name PERVIOUS    Cmin   Cmax   Tbase   FWF  SDO  FWO   SD100
          Name REMOVAL     Dplow Fout  Fimp Fperv Fimelt  (Fsub Scatch)

Remarks:  Name      name assigned to snowpack parameter set.
          Cmin      minimum melt coefficient (in/hr-deg F or mm/hr-deg C).
          Cmax      maximum melt coefficient (in/hr-deg F or mm/hr-deg C).
          Tbase     snow melt base temperature (deg F or deg C).
          FWF       ratio of free water holding capacity to snow depth (fraction).
          SDO       initial snow depth (in or mm water equivalent).
          FWO       initial free water in pack (in or mm).
          SNNO      fraction of impervious area that can be plowed.
          SDIOO     snow depth above which there is 100% cover (in or mm water
                     equivalent).
          Dplow     depth of snow on plowable areas at which snow removal begins (in or
                     mm).
          Fout      fraction of snow on plowable area transferred out of watershed.
          Fimp      fraction of snow on plowable area transferred to impervious area by
                     plowing.
          Fperv     fraction of snow on plowable area transferred to pervious area by
                     plowing.
          Fimelt    fraction of snow on plowable area converted into immediate melt.
          Fsub      fraction of snow on plowable area transferred to pervious area in
                     another subcatchment.
          Scatch    name of subcatchment receiving the Fsub fraction of transferred snow.
          Use one set of PLOWABLE,  IMPERVIOUS, and PERVIOUS lines for each snow pack
          parameter set created. Snow pack parameter sets are  associated with  specific
          subcatchments in the [SUBCATCHMENTS] section. Multiple subcatchments can share
          the same set of snow pack parameters.

          The PLOWABLE line contains parameters for the impervious area of a subcatchment
          that is subject to snow removal by plowing but not to areal depletion. This area is the
          fraction SNNO of the total impervious area. The IMPERVIOUS line  contains parameter
                                        300

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values for the remaining impervious area and the PERVIOUS line does the same for
the entire pervious area. Both of the latter two areas are subject to areal depletion.

The  REMOVAL  line describes  how snow removed  from  the  plowable  area  is
transferred onto other areas. The various transfer fractions should sum to no  more
than  1.0. If the line is omitted then no snow  removal takes place.
                               301

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Section:    [JUNCTIONS]

Purpose:   Identifies each junction node of the drainage system. Junctions are points in space
           where channels and pipes connect together. For sewer systems they can be either
           connection fittings or manholes.

Format:    Name   Elev   (Ymax   YO   Ysur  Apond)
Remarks:  Name

           Elev

           Ymax

           YO

           Ysur


           Apond
name assigned to junction node.
elevation of junction invert (ft or m).
depth from ground to invert elevation (ft or m) (default is 0).
water depth at start of simulation (ft or m) (default is 0).
maximum additional head above ground elevation that manhole junction
can sustain under surcharge conditions (ft or m) (default is 0).
area subjected to surface ponding once water depth exceeds Ymax (ft2 or
m2) (default is 0).
           If Ymax is 0 then SWMM sets the maximum depth equal to the distance from the
           invert to the top of the highest connecting link.

           If the junction is  part of  a force main section of the system then set Ysur to the
           maximum pressure that the system can sustain.

           Surface ponding can only occur when Apond is non-zero and the ALLOW_PONDING
           analysis option is turned on.
                                         302

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Section:    [OUTFALLS]
Purpose:
Formats:
Identifies each outfall node (i.e., final downstream boundary) of the drainage system
and the  corresponding water stage elevation. Only one link can be incident on an
outfall node.
Remarks:
Name
Name
Name
Name
Name

Name
Elev
Stage
Tcurve
           Tseries
           Gated
          RouteTo
Elev
Elev
Elev
Elev
Elev
                        FREE
                        NORMAL
                        FIXED
                        TIDAL
                        TIMESERIES
 (Gated)   (RouteTo)
 (Gated)   (RouteTo)
Stage    (Gated)    (RouteTo)
Tcurve   (Gated)    (RouteTo)
Tseries  (Gated)
(RouteTo)
   name assigned to outfall node.
   invert elevation (ft or m).
   elevation of fixed stage outfall (ft or m).
   name of curve in [CURVES] section containing tidal height (i.e., outfall
   stage) v.  hour of day over a complete tidal cycle.
   name of time series in [TIMESERIES] section that describes how outfall
   stage varies with time.
   YES or NO depending on whether a flap gate is present that prevents
   reverse flow. The default is NO.
   optional name of a subcatchment that receives the outfall's discharge.
   The default is not to route the outfall's discharge.
                                        303

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Section:    [DIVIDERS]

Purpose:   Identifies each flow divider node of the drainage system. Flow dividers are junctions
           with exactly two outflow conduits where the total outflow is divided between the two in
           a prescribed manner.

Formats:   Name Elev DivLink  OVERFLOW  (Ymax YO  Ysur  Apond)
           Name Elev DivLink  CUTOFF  Qmin   (Ymax YO Ysur Apond)
           Name Elev DivLink  TABULAR Dcurve  (Ymax YO Ysur  Apond)
           Name Elev DivLink  WEIR     Qmin  Ht  Cd (Ymax  YO Ysur Apond)
Remarks:  Name
           Elev
           DivLink
           Qmin

           Dcurve
           Ht
           Cd
           Ymax
           YO
           Ysur

           Apond
name assigned to divider node.
invert elevation (ft or m).
name of link to which flow is diverted.
flow at which diversion begins for either a CUTOFF or WEIR divider (flow
units).
name of curve for TABULAR divider that relates diverted flow to total flow.
height of WEIR divider (ft or m).
discharge coefficient for WEIR divider.
depth from ground to invert elevation (ft or m) (default is 0).
water depth at start of simulation (ft or m) (default is 0).
maximum additional head above ground elevation that node can sustain
under surcharge conditions (ft or m) (default is 0).
area subjected to surface ponding once water depth exceeds  Ymax (ft2 or
m2) (default is 0).
           If Ymax is 0 then SWMM sets the maximum depth equal to the distance from the
           invert to the top of the highest connecting link.

           Surface ponding can only occur when Apond is non-zero and the ALLOW_PONDING
           analysis option is turned on.

           Divider nodes are only active under the Steady Flow or Kinematic Wave analysis
           options. For Dynamic Wave flow routing they behave the same as Junction nodes.
                                         304

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Section:    [STORAGE]

Purpose:   Identifies each storage node of the drainage system.  Storage nodes can have any
           shape as specified by a surface area versus water depth relation.

Formats:
Name Elev Ymax  YO TABULAR     Acurve    (Apond Fevap Psi  Ksat  IMD)
Name Elev Ymax  YO FUNCTIONAL Al  A2 AO  (Apond Fevap Psi  Ksat  IMD)

Remarks:  Name      name assigned to storage node.
           Elev      invert elevation (ft or m).
           Ymax      maximum water depth possible (ft or m).
           YO        water depth at the start of the simulation (ft or m).
           Acurve   name of curve in [CURVES] section with surface area (ft2 or m2) as a
                     function of depth (ft or m) for TABULAR geometry.
           Al        coefficient of FUNCTIONAL relation between surface area and depth.
           A2        exponent of FUNCTIONAL relation between surface area and depth.
           AO        constant of FUNCTIONAL relation between surface area and depth.
           Apond     this parameter has been deprecated - use 0.
           Fevap     fraction of potential evaporation from surface realized (default is 0).
           Psi       soil suction head (inches or mm).
           Ksa t      soil saturated hydraulic conductivity (in/hr or mm/hr).
           IMD       soil initial moisture deficit (fraction).

           Al, A2, and AO are used in  the following expression that relates surface area (ft2 or
           m2) to water depth (ft or m) for a storage unit with FUNCTIONAL geometry:

                  Area = AO + AlDepthA2

           For TABULAR geometry, the surface area curve will be extrapolated outwards to
           meet the unit's maximum depth if need be.

           The parameters Psi,  Ksat, and IMD need only be supplied if seepage loss through
           the soil at the bottom and sloped sides of the storage unit should be considered.
           They  are  the  same  Green-Ampt   infiltration   parameters  described  in   the
           [INFILTRATION] section. If Ksat is zero then no seepage occurs while if IMD is
           zero then seepage occurs at a constant rate equal to Ksat.  Otherwise seepage rate
           will vary with storage depth.
                                         305

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Section:    [CONDUITS]

Purpose:   Identifies each conduit link of the drainage system. Conduits are pipes or channels
           that convey water from one node to another.

Format:    Name   Nodel   Node2  Length   N  Zl  Z2   (QO   Qmax)
Remarks:  Name
           Nodel
           Node2
           Length
           N
           Zl

           Z2

           QO
           Qmax
name assigned to conduit link.
name of upstream node.
name of downstream node.
conduit length (ft or m).
value of n (i.e., roughness parameter) in Manning's equation.
offset of upstream end of conduit invert above the invert elevation of its
upstream node (ft or m).
offset of downstream end of conduit invert above the invert elevation of
its downstream node (ft or m).
flow in conduit at start of simulation (flow units) (default is 0).
maximum flow allowed in the conduit (flow units) (default is no limit).
           The figure below illustrates the meaning of the zi and Z2 parameters.
           These offsets are expressed as a relative  distance above the node  invert  if the
           LINK_OFFSETS option is set to DEPTH (the default) or as an absolute elevation if it is
           Set to ELEVATION.
                                         306

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Section:   [PUMPS]

Purpose:  Identifies each pump link of the drainage system.

Format:   Name  Nodel   Node2  Pcurve   (Status   Startup   Shutoff)

Remarks:  Name         name assigned to pump link.
          Nodel        name of node on inlet side of pump.
          Node2        name of node on outlet side of pump.
          Pcurve       name of pump curve listed in the [CURVES] section of the input.
          status       status at start of simulation (either ON or OFF; default is ON).
          startup      depth at inlet node when pump turns on (ft or m) (default is 0).
          shutoff      depth at inlet node when pump shuts off (ft or m) (default is 0).

          See Section 3.2 for a description of the different types of pumps available.
                                        307

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Section:   [ORIFICES]

Purpose:   Identifies each orifice link of the drainage system. An orifice link serves to limit the
           flow exiting a node and  is often used  to model  flow diversions and storage node
           outlets.
Format:   Name   Nodel  Node2   Type   Offset   Cd   (Gated   Orate)
Remarks:  Name

           Nodel

           Node2

           Type

           Offset
           Cd

           Flap

           Orate
name assigned to orifice link.
name of node on inlet end of orifice.
name of node on outlet end of orifice.
orientation of orifice: either SIDE or BOTTOM.
amount that a Side Orifice's bottom or the position of a Bottom Orifice is
offset above the invert of inlet node (ft or m, expressed as either a depth
or as an elevation, depending on the LINK_OFFSETS option setting).
discharge coefficient (unitless).
YES if flap gate present to  prevent reverse flow, NO if not (default is NO).
time in decimal hours to open a fully closed orifice (or close a fully open
one). Use 0 if the orifice can  open/close instantaneously.
           The geometry of an orifice's opening must be described in the [XSECTIONS] section.
           The only allowable shapes are CIRCULAR and RECT CLOSED (closed rectangular).
                Regulator
                Structure
                               Orifice
                                          308

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Section:    [WEIRS]

Purpose:   Identifies each  weir link of the drainage system. Weirs are used to model  flow
           diversions and storage node outlets.

Format:
    Name Nodel Node2 Type CrestHt  Cd  (Gated EC Cd2 Sur  (Width Surface))

Remarks:   Name      name assigned to weir link.
           Nodel     name of node on inlet side of wier.
           Node2     name of node on outlet side of weir.
           Type      TRANSVERSE,  SIDEFLOW, V-NOTCH, TRAPEZOIDAL Or ROADWAY.
           CrestHt   amount that the weir's crest is offset above the invert of inlet node (ft or
                     m, expressed as either a depth or as an elevation, depending on the
                     LINKJDFFSETS option setting).
           cd        weir discharge coefficient (for CFS  if using US flow units or CMS if using
                     metric flow units).
           Gated     YES if flap gate present to prevent reverse flow, NO if not (default is NO).
           EC        number of end contractions for TRANSVERSE or TRAPEZOIDAL weir
                     (default is 0).
           cd2       discharge coefficient for triangular ends of a TRAPEZOIDAL weir (for
                     CFS if using US flow units or CMS  if using metric flow units) (default is
                     value of cd).
           Sur       YES if the weir can surcharge (have an upstream water level higher than
                     the  height of the opening); NO if it cannot (default is YES).
           width     width of road lanes and shoulders for ROADWAY weir (ft or m).
           Surface   type of road surface for ROADWAY weir: PAVED or GRAVEL.

           The geometry of a  weir's  opening is described in the  [XSECTIONS] section.  The
           following shapes must be used with each type of weir:
Weir Type
Transverse
Sideflow
V-Notch
Trapezoidal
Roadway
Cross-Section Shape
RECTJDPEN
RECTJDPEN
TRIANGULAR
TRAPEZOIDAL
RECTJDPEN
           The ROADWAY  weir  is a  broad  crested  rectangular  weir  used model  roadway
           crossings usually in conjunction with culvert-type conduits. It uses the FHWA HDS-5
           method to determine a discharge coefficient  as a function of flow depth and roadway
           width and surface. If no roadway data are provided then the weir behaves as a
                                         309

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TRANSVERSE weir with cd as its discharge coefficient. Note that if roadway data are
provided, then  values for the other optional weir parameters (NO for Gated,  o for
EC,  o for  cd2, and NO for Sur) must be entered even though they do not apply to
ROADWAY weirs.
                              310

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Section:    [OUTLETS]

Purpose:   Identifies each outlet flow control device of the drainage system. These devices are
           used to model outflows from storage units or flow diversions that have a user-defined
           relation between flow rate and water depth.

Formats:   Name  Nodel Node2 Offset TABULAR/DEPTH     Qcurve  (Gated)
           Name  Nodel Node2 Offset TABULAR/HEAD      Qcurve  (Gated)
           Name  Nodel Node2 Offset FUNCTIONAL/DEPTH Cl  C2  (Gated)
           Name  Nodel Node2 Offset FUNCTIONAL/HEAD  Cl  C2  (Gated)
Remarks:   Name
           Nodel
           Node2
           Offset


           Qcurve
           Cl, C2
           Gated
name assigned to outlet link.
name of node on inlet end of link.
name of node on outflow end of link.
amount that the outlet is offset above the invert of inlet node (ft or m,
expressed as either a depth or as an elevation, depending on the
LINK_OFFSETS option setting).
name of the rating curve listed in the [CURVES] section that describes
outflow rate (flow units) as a function of:
•  water depth above the offset elevation at the inlet node (ft or m) for a
   TABULAR/DEPTH Outlet
•  head difference (ft or m) between the inlet and outflow nodes for a
   TABULAR/HEAD Outlet.
coefficient and exponent, respectively,  of a power function that relates
outflow (Q) to:
•  water depth (ft or m) above the offset elevation at the inlet node for a
   FUNCTIONAL/DEPTH Outlet
•  head difference (ft or m) between the inlet and outflow nodes for a
   FUNCTIONAL/HEAD Outlet.
(i.e.,  Q = CIHC2 where H is either depth or head).
YES if flap gate present to prevent reverse flow, NO if not (default is NO).
                                         311

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Section:    [XSECTIONS]

Purpose:   Provides cross-section geometric data for conduit and regulator links of the drainage
           system.

Formats:   Link   Shape         Geoml  Geom2 GeomS Geom4  (Barrels Culvert)
           Link   CUSTOM       Geoml  Curve (Barrels)
           Link   IRREGULAR    Tsect

Remarks:   Link      name of the conduit, orifice, or weir.
           shape     cross-section shape (see Tables D-1 below or 3-1 for available shapes).
           Geoml     full height of the cross-section (ft or m).
           Geom2-4  auxiliary parameters (width, side slopes, etc.) as listed in Table D-1.
           Barrels  number of barrels (i.e., number of parallel pipes of equal size, slope,  and
                     roughness) associated with a conduit (default is 1).
           Culvert  code number from Table A.10 for the conduit's inlet geometry if it is a
                     culvert subject to possible inlet flow control (leave blank otherwise).
           Curve     name of a  Shape Curve in the [CURVES] section that defines how width
                     varies with depth.
           Tsect     name of an entry in  the [TRANSECTS] section that describes the cross-
                     section geometry of an irregular channel.

           The Culvert code number is used only for conduits that act as culverts and should be
           analyzed for inlet control conditions using the FHWA HDS-5 method.

           The CUSTOM shape is  a closed  conduit whose width versus height is described  by a
           user-supplied Shape Curve.

           An IRREGULAR cross-section is used to model an  open channel whose geometry is
           described by a Transect object.
                                         312

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        Table D-1 Geometric parameters of conduit cross sections
Shape
CIRCULAR
FORCE_MAIN
FILLED_CIRCULAR2
RECT_CLOSED
RECT_OPEN
TRAPEZOIDAL
TRIANGULAR
HORIZ_ELLIPSE
VERT_ELLIPSE
ARCH
PARABOLIC
POWER
RECT_TRIANGULAR
RECT_ROUND
MODBASKETHANDLE
EGG
HORSESHOE
GOTHIC
CATENARY
SEMIELLIPTICAL
BASKETHANDLE
SEMICIRCULAR
Geoml
Diameter
Diameter
Diameter
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Full Height
Geom2

Roughness1
Sediment
Depth
Top Width
Top Width
Base Width
Top Width
Max. Width
Max. Width
Max. Width
Top Width
Top Width
Top Width
Top Width
Base Width







GeomS





Left Slope3

Size Code4
Size Code4
Size Code5

Exponent
Triangle
Height
Bottom
Radius
Top Radius6







Geom4





Right Slope3
















1C-factors are used when H-W is the FORCE_MAIN_EQUATION choice in the [OPTIONS]
section while roughness heights (in inches or mm) are used forD-w.
2A circular conduit partially filled with sediment to a specified depth.
3Slopes are horizontal run / vertical rise.
4Size code of a standard shaped elliptical pipe as listed in Appendix A11. Leave blank (or
0) if the pipe has a custom dimensions.
5Size code of a standard arch pipe as listed in Appendix A12. Leave blank (or 0) if the
pipe has custom dimensions).
6Set to zero to use a standard modified baskethandle shape whose top radius is half the
base width.
                                   313

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Section:   [LOSSES]

Purpose:   Specifies minor head loss coefficients, flap gates, and seepage rates for conduits.

Formats:   Conduit   Kentry  Kexit   Kavg   (Flap  Seepage)

Remarks:  Conduit   name of conduit.
           Kentry    entrance minor head loss coefficient.
           Kexit     exit minor head loss coefficient.
           Kavg      average minor head loss coefficient across length of conduit.
           Flap      YES if conduit has a flap valve that prevents back flow, NO otherwise.
                      (Default is NO).
           Seepage   Rate of seepage loss into surrounding soil (in/hr or mm/hr). (Default is 0.)

           Minor losses  are only computed for the Dynamic Wave  flow routing option (see
           [OPTIONS] section). They are computed as Kv2/2g where K = minor loss coefficient, v
           = velocity, and g  = acceleration of gravity. Entrance losses are based on the velocity
           at the entrance of the conduit, exit losses on the exit velocity, and  average losses on
           the average velocity.

           Only enter data for  conduits that actually have minor losses, flap valves, or seepage
           losses.
                                          314

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Section:    [TRANSECTS]

Purpose:   Describes the cross-section geometry of natural channels or conduits with irregular
           shapes following the HEC-2 data format.

Formats:   NC  Nleft  Nright   Nchanl
           XI  Name   Nsta Xleft Xright  000  Lfactor  Wfactor Eoffset
           GR  Elev   Station   ...   Elev  Station

Remarks:  Nleft     Manning's n of right overbank portion of channel (use 0 if no change
                     from previous NC line).
           Nright   Manning's n of right overbank portion of channel (use 0 if no change
                     from previous NC line.
           Nchanl   Manning's n of main channel portion of channel (use 0 if no change from
                     previous NC line.
           Name      name assigned to transect.
           Nsta      number of stations across cross-section at which  elevation data is
                     supplied.
           xieft     station position which ends the left overbank portion of the channel (ft or
                     m).
           Xright   station position which begins the right overbank portion of the channel (ft
                     or m).
           Lfactor  meander modifier that represents the ratio of the length of a meandering
                     main channel to the length of the overbank area that surrounds it (use 0
                     if not applicable).
           Wfactor  factor by which distances between stations should be multiplied to
                     increase (or decrease) the width of the  channel (enter 0 if not
                     applicable).
           Eoffset  amount added (or subtracted) from the elevation of each station (ft or m).
           Elev      elevation of the channel bottom at a cross-section station relative to
                     some fixed reference  (ft or m).
           station  distance of a cross-section station from some fixed reference (ft or m).

           Transect geometry is described as shown below, assuming  that one is looking in a
           downstream direction:
                                         315

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                    Left
                 Oveibiink
    Pi. ilit
    Overbiink
                       Xleft
                                   St.itioii
Xi kjl*
The first line in this section must always be a NC line. After that, the NC line is only
needed when a transect has different Manning's n values than the previous one.

The Manning's n values on the NC line will supersede any roughness value entered
for the conduit which uses the irregular cross-section.

There should be one xi line for each transect. Any number of GR lines may follow,
and each GR line can have any number of Elevation-Station data  pairs. (In HEC-2 the
GR line is limited to 5 stations.)

The station that defines the left overbank boundary on the xi line must correspond to
one of the station entries on the GR lines that follow. The same holds true for the right
overbank boundary. If there is no match, a warning will be issued and the program
will assume that no overbank area exists.

The meander  modifier  is applied to all conduits that use  this particular transect for
their cross  section.  It assumes that the length supplied for these conduits  is that of
the  longer main  channel. SWMM will  use the  shorter  overbank length  in  its
calculations while increasing the main  channel roughness to account for its longer
length.
                                316

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Section:   [CONTROLS]
Purpose:  Determines how pumps and regulators will be adjusted based on simulation time or
          conditions at specific nodes and links.
Formats:  Each control rule is a series of statements of the form:
                 rulelD
                 condition_l
                 condition  2
                 condition_3
                 condition  4

                 action_l
                 action 2

                 action_3
                 action 4
RULE
IF
AND
OR
AND
Etc.
THEN
AND
Etc.
ELSE
AND           _
Etc.
PRIORITY value
Remarks:  Rule ID
          condition  n
          action_n
          value
                 an ID label assigned to the rule.
                 a condition clause.
                 an action clause.
                 a priority value (e.g., a number from 1 to 5).
          A condition clause of a Control Rule has the following format:
          Object   Name  Attribute  Relation   Value
          where  object is a category of object,  Name is the object's  assigned ID name,
          Attribute  is the  name of an  attribute or property of the object, Relation is  a
          relational operator (=, <>, <, <=, >, >=), and Value is an attribute value.

          Some examples of condition clauses are:
              NODE  N23  DEPTH   >  10
              PUMP  P45  STATUS  =  OFF
              SIMULATION TIME =  12:45:00

          The objects and attributes that can appear in a condition clause are as follows:
                                        317

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Object
NODE



LINK



CONDUIT


PUMP




ORIFICE


WEIR


OUTLET


SIMULATION

SIMULATION



Attributes
DEPTH
HEAD
VOLUME
INFLOW
FLOW
DEPTH
TIMEOPEN
TIMECLOSED
STATUS
TIMEOPEN
TIMECLOSED
STATUS
SETTING
FLOW
TIMEOPEN
TIMECLOSED
SETTING
TIMEOPEN
TIMECLOSED
SETTING
TIMEOPEN
TIMECLOSED
SETTING
TIMEOPEN
TIMECLOSED
TIME

DATE
MONTH
DAY
CLOCKTIME
Value
numerical value
numerical value
numerical value
numerical value
numerical value
numerical value
decimal hours or hr:min
decimal hours or hr:min
OPEN or CLOSED
decimal hours or hr:min
decimal hours or hr:min
ON or OFF
pump curve multiplier
numerical value
decimal hours or hr:min
decimal hours or hr:min
fraction open
decimal hours or hr:min
decimal hours or hr:min
fraction open
decimal hours or hr:min
decimal hours or hr:min
rating curve multiplier
decimal hours or hr:min
decimal hours or hr:min
elapsed time in decimal hours or
hr:min:sec
month/day/year
month of year (January = 1)
day of week (Sunday = 1)
time of day in hr:min:sec
TIMEOPEN  is the  duration  a link has been in an OPEN or ON state or have its
SETTING be greater than zero; TIMECLOSED  is the duration it has remained in a
CLOSED or OFF state or have its SETTING be zero.

An action clause of a Control Rule can have one of the following formats:
                              318

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PUMP id  STATUS =  ON/OFF
PUMP/ORIFICE/WEIR/OUTLET id SETTING  = value

where the  meaning of SETTING depends on the object being controlled:
•   for Pumps it is a multiplier applied to the flow computed from the pump curve,
•   for Orifices it is the fractional amount that the orifice is fully open,
•   for Weirs it is the fractional amount of the original freeboard that exists (i.e., weir
    control is accomplished by moving the crest height up or down),
•   for Outlets it is a multiplier applied to the flow computed from the outlet's rating
    curve.

Modulated controls are control rules that provide for a continuous degree of control
applied to a pump or flow regulator as determined  by the value of some controller
variable, such as water depth at a node, or by time. The functional relation between
the control setting and the controller variable is specified by using a control curve, a
time series, or a PID controller. To model these types of controls, the value entry on
the  right-hand side of  the  action  clause  is  replaced  by  the keyword CURVE,
TIMESERIES, or PID and followed by the id name of the respective control curve or
time series or by the gain, integral time (in minutes), and derivative time (in minutes)
of a PID controller. For direct action control the gain  is  a  positive number while for
reverse action control  it must be a negative  number. By convention, the controller
variable used in a control curve or PID control will always be  the object and attribute
named in the last condition clause of the rule. The value specified for this clause will
be the setpoint used in a PID controller.

Some examples of action clauses are:
    PUMP  P67  STATUS = OFF
    ORIFICE  0212 SETTING =0.5
    WEIR  W25  SETTING =  CURVE C25
    ORIFICE  ORI_23  SETTING  = PID  0.1  0.1  0.0

Only the RULE,  IF and THEN portions of a rule are required; the other portions are
optional. When mixing AND and OR clauses, the OR operator  has higher precedence
than AND, i.e.,
    IF A  or  B  and  C
is equivalent to
    IF (A or  B)  and C.
If the interpretation was meant to be
    IF A  or  (B and C)
then this can be expressed using two rules as in
                               319

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              IF A THEN ...
              IF B and C THEN ...

          The PRIORITY value is used to determine which rule applies when two or more rules
          require that conflicting  actions  be taken on a link. A conflicting rule with a higher
          priority value  has  precedence  over one with a  lower value (e.g., PRIORITY  5
          outranks PRIORITY l). A rule without a priority  value always has a lower priority
          than one with  a value. For two rules with the  same  priority value, the rule that
          appears first is given the higher priority.

Examples:     ; Simple time-based pump control
              RULE Rl
              IF SIMULATION  TIME >  8
              THEN PUMP 12 STATUS = ON
              ELSE PUMP 12 STATUS = OFF

              ; Multi-condition orifice gate control
              RULE R2A
              IF NODE  23 DEPTH > 12
              AND LINK 165 FLOW > 100
              THEN ORIFICE R55 SETTING =0.5

              RULE R2B
              IF NODE  23 DEPTH > 12
              AND LINK 165 FLOW > 200
              THEN ORIFICE R55 SETTING =1.0

              RULE R2C
              IF NODE  23 DEPTH <= 12
              OR LINK  165  FLOW <= 100
              THEN ORIFICE R55 SETTING = 0

              ; PID controller that attempts to keep Node 23's depth at 12:
              RULE PID_1
              IF NODE  23 DEPTH <> 12
              THEN ORIFICE R55 SETTING = PID  0.5  0.1  0.0

              ; Pump station operation with a main (N1A) and lag (N1B) pump
              RULE R3A
              IF NODE  Nl DEPTH > 5
              THEN PUMP N1A  STATUS  = ON

              RULE R3B
              IF PUMP  N1A  TIMEOPEN  > 2:30
              THEN PUMP NIB  STATUS  = ON
              ELSE PUMP NIB  STATUS  = OFF
                                        320

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RULE R3C
IF NODE Nl  DEPTH <= 0.5
THEN PUMP N1A STATUS = OFF
AND PUMP NIB  STATUS = OFF
                        321

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Section:   [POLLUTANTS]

Purpose:   Identifies the pollutants being analyzed.

Format:
    Name  Units Grain Cgw Cii  Kd  (Sflag CoPoll  CoFract  Cdwf  Cinit)

Remarks:  Name      name assigned to pollutant.
           uni ts     concentration units  (MG/L for milligrams per liter, UG/L for micrograms
                      per liter, or #/L for direct count per liter).
           Grain     concentration of pollutant in rainfall (concentration units).
           Cgw       concentration of pollutant in groundwater (concentration units).
           cii        concentration of pollutant in inflow/infiltration (concentration units).
           Kdecay    first-order decay coefficient (1/days).
           sflag     YES if pollutant buildup occurs only when there is snow cover, NO
                      otherwise (default is NO).
           CoPoll    name of co-pollutant (default is no co-pollutant designated by a *).
           CoFract  fraction of co-pollutant concentration (default is 0).
           cdwf      pollutant concentration  in dry weather flow (default is 0).
           cini t     pollutant concentration  throughout the conveyance system  at the start of
                      the simulation (default is 0).

           FLOW is a reserved word and cannot be used to name a pollutant.

           Parameters sflag through  cinit can  be omitted  if they assume  their default
           values. If there is no co-pollutant but non-default values for cdwf or  cinit, then
           enter an asterisk (*) for the co-pollutant name.

           When pollutant X has a co-pollutant Y, it means that fraction CoFract of pollutant Y's
           runoff concentration is added to pollutant X's runoff concentration when wash off from
           a subcatchment is computed.

           The dry weather flow concentration can  be  overridden for any specific node of the
           conveyance system by editing the node's  Inflows property.
                                          322

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Section:   [LANDUSES]

Purpose:  Identifies the various  categories of land  uses within the drainage area.  Each
          subcatchment area can be assigned a different mix of land uses. Each land use can
          be subjected to a different street sweeping schedule.

Format:   Name   (Sweeplnterval   Availability  LastSweep)

Remarks:  Name             land use name.
          Sweep interval   days  between street sweeping.
          Availability    fraction of pollutant buildup available for removal by street
                            sweeping.
          LastSweep       days  since last sweeping at start of the simulation.
                                        323

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Section:   [COVERAGES]

Purpose:  Specifies the percentage of a subcatchment's area that is covered by each category
          of land use.

Format:   Subcat   Landuse   Percent  Landuse   Percent

Remarks:  Subcat    subcatchment name.
          Landuse   land use name.
          Percen t   percent of subcatchment area.

          More than one pair of land use - percentage values can be entered per line. If more
          than one line is needed, then the subcatchment name must still be  entered first on
          the succeeding lines.

          If a land use does not pertain to a subcatchment, then it does not have to be entered.

          If no land uses are associated with a subcatchment then no contaminants will appear
          in the runoff from the subcatchment.
                                        324

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Section:    [LOADINGS]

Purpose:   Specifies  the pollutant buildup that exists on each subcatchment at the start of a
           simulation.
Format:
Subcat   Pollut   InitBuildup  Pollut   InitBuildup ...
Remarks:  Subcat

           Pollut

           InitBuildup
                  name of a subcatchment.
                  name of a pollutant.
                  initial buildup of pollutant (Ibs/acre or kg/hectare).
           More than one pair of pollutant - buildup values can be entered per line. If more than
           one line is needed, then the subcatchment name must still be entered first on  the
           succeeding lines.

           If an initial buildup is not specified for a pollutant, then its initial buildup is computed
           by applying  the  DRY_DAYS  option (specified  in  the  [OPTIONS] section)  to  the
           pollutant's buildup function for each land use in the subcatchment.
                                         325

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Section:    [BUILDUP]

Purpose:   Specifies the rate at which pollutants build up over different land uses between rain
           events.
Format:
Landuse   Pollutant   FuncType  Cl   C2   C3   PerUnit
Remarks:  Landuse

           Pollutant

           FuncType

           Cl,C2, C3

           PerUnit
              land use name.
              pollutant name.
              buildup function type: (POW / EXP /  SAT /  EXT).
              buildup function parameters (see Table D-2).
              AREA if buildup is per unit area, CURBLENGTH if per length of curb.
           Buildup is measured  in pounds  (kilograms)  per unit  of area (or curb  length)  for
           pollutants whose concentration units are either mg/L  or ug/L. If the concentration
           units are counts/L, then the buildup is expressed as counts per unit of area (or curb
           length).

             Table D-2 Pollutant buildup functions (t is antecedent dry days)
Name
POW
EXP
SAT
EXT
Function
Power
Exponential
Saturation
External
Equation
Min(C1,C2*tC3)
C1*(1 -exp(-C2*t))
C1*t/(C3 + t)
See below
           For the EXT buildup function, C1 is the maximum possible buildup (mass per area or
           curb  length), C2  is a scaling factor, and C3 is the name of a Time Series that
           contains buildup rates (as mass per area or curb length per day) as a function of
           time.
                                         326

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Section:    [WASHOFF]
Purpose:   Specifies the rate at which pollutants are washed off from different land uses during
           rain events.

Format:    Landuse   Pollutant   FuncType   Cl   C2   SweepRmvl  BmpRmvl
Remarks:  Landuse

           Pollutant

           FuncType

           Cl,  C2

           SweepRmvl

           BmpRmvl
land use name.
pollutant name.
washoff function type: EXP  /  RC  /  EMC.
washoff function coefficients(see Table D-3).
street sweeping removal efficiency (percent)
BMP removal efficiency (percent).
                         Table D-3 Pollutant wash off functions
Name
EXP
RC
EMC
Function
Exponential
Rating Curve
Event Mean
Concentration
Equation
C1 (runoff)02 (buildup)
C1 (runoff)02
C1
Units
Mass/hour
Mass/sec
Mass/Liter
           Each washoff function expresses its results in different units.

           For the Exponential function the  runoff variable is expressed in catchment depth
           per unit of time (inches per hour or millimeters per hour), while for the Rating Curve
           function it is in whatever flow units were specified in the [OPTIONS] section  of the
           input file (e.g., CFS, CMS, etc.).

           The buildup parameter in the Exponential function is the current total buildup over
           the subcatchment's land use area  in mass units. The  units of ci in the Exponential
           function are  (in/hr) -°2 per hour (or (mm/hr) ~C2 per hour). For the Rating Curve
           function, the units of ci  depend on the flow units employed. For the EMC (event
           mean concentration) function, ci is always in concentration units.
                                         327

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Section:   [TREATMENT]

Purpose:   Specifies the degree of treatment  received by pollutants at  specific nodes of the
           drainage system.

Format:    Node   Pollut   Result = Func
Remarks:  Node
           Pollut
           Result
           Func
Name of node where treatment occurs.
Name of pollutant receiving treatment.
Result computed by treatment function. Choices are:
c (function computes effluent concentration)
R (function computes fractional removal).
mathematical function expressing treatment result in terms of pollutant
concentrations, pollutant removals, and other standard variables (see
below).
           Treatment functions can be any well-formed mathematical expression involving:
               inlet pollutant concentrations (use the pollutant name to represent a
               concentration)
               removal of other pollutants (use R_ pre-pended to the pollutant name to
               represent removal)
               process variables which include:
               FLOW for flow rate into node (user's flow units)
               DEPTH for water depth above node invert (ft or m)
               AREA for node surface area (ft2 or m2)
               DT for routing time step (seconds)
               HRT for hydraulic residence time (hours)

           Any of the following math functions can be used in  a treatment function:
               •   abs(x) for absolute value of x
               •   sgn(x) which is +1 for x >=  0 or -1 otherwise
               •   step(x) which is 0 forx <= 0 and 1 otherwise
               •   sqrt(x) for the square root of x
               •   log(x) for logarithm base e  of x
               •   Iog10(x) for logarithm base 10 of x
               •   exp(x) for e raised to the x  power
               •   the standard trig functions (sin, cos, tan, and  cot)
               •   the inverse trig functions (asin, acos, atan, and acot)
               •   the hyperbolic trig functions (sinh, cosh, tanh, and coth)
           along with the standard operators +, -, *, /, A (for exponentiation ) and any level of
           nested parentheses.
                                          328

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Examples: ; 1-st order decay of BOD
         Node23   BOD   C = BOD * exp(-0.05*HRT)

         ; lead removal is 20% of TSS removal
         Node23   Lead  R = 0.2 * R TSS
                                    329

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Section:   [INFLOWS]

Purpose:  Specifies external hydrographs and pollutographs that enter the drainage system at
          specific nodes.

Formats:  Node FLOW   Tseries   (FLOW    (1.0      Sfactor Base Pat))
          Node Pollut Tseries   (Type    (Mfactor Sfactor Base Pat))
Remarks:  Node

          Pollut

          Tseries


          Type


          Mfactor
          Sfactor
          Base
          Pat
       name of node where external inflow enters.
       name of pollutant.
       name of time series in [TIMESERIES] section describing how
       external flow or pollutant loading varies with time.
       CONCEN if pollutant inflow is described as a concentration, MASS
       if it is described as a mass flow rate (default is CONCEN).
       the factor that converts the inflow's mass flow rate units into the
       project's mass units per second, where the project's mass units
       are those specified for the pollutant in the [POLLUTANTS] section
       (default is 1.0 - see example below).
       scaling  factor that multiplies the recorded time series values
       (default is 1.0).
       constant baseline value added to the time series value (default is
       0.0).
       name of optional time pattern in [PATTERNS] section used to
       adjust the baseline value on a periodic basis.
          External inflows are represented by both a constant and time varying component as
          follows:
              Inflow =  (Baseline  value) * (Pattern factor)  +
                         (Scaling factor) * (Time  series  value)

          If an external inflow of a pollutant concentration is specified for a  node, then there
          must also be an external inflow of FLOW provided for the same node, unless the node
          is an Outfall. In that case a pollutant can enter the system during periods when the
          outfall is submerged and reverse flow occurs.
Examples: NODE2
          NODE33
FLOW   N2FLOW
TSS    N33TSS  CONCEN
           ;Mass inflow of  BOD in time  series  N65BOD  given  in Ibs/hr
           ;(126 converts Ibs/hr  to mg/sec)
           NODE65   BOD  N65BOD  MASS  126


           ;Flow inflow with baseline and scaling factor
           N176  FLOW  FLOW 176   FLOW   1.0   0.5  12.7  FlowPat
                                        330

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Section:   [DWF]

Purpose:   Specifies dry weather flow and its quality entering the drainage system at specific
           nodes.

Format:    Node   Type  Base   (Patl   Pat2   Pat3  Pat4)

Remarks:  Node       name of node where dry weather flow enters.
           Type       keyword FLOW for flow or pollutant name for quality constituent.
           Base       average baseline value for corresponding constituent  (flow or
                      concentration units).
           Patl,
           Pat2,
           etc.        names of up to four time patterns appearing in the [PATTERNS] section.

           The actual dry weather input will equal the product of the baseline value and any
           adjustment factors supplied by the specified patterns. (If not supplied, an adjustment
           factor defaults to 1.0.)

           The patterns can be any combination of monthly, daily, hourly and weekend hourly
           patterns, listed in any order. See the [PATTERNS] section for more details.
                                          331

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Section:    [RDII]

Purpose:   Specifies the parameters that  describe rainfall-dependent  infiltration/inflow  (RDII)
           entering the drainage system at specific nodes.

Format:    Node   UHgroup  SewerArea

Remarks:   Node         name of a node.
           UHgroup      name of an RDII unit hydrograph group specified in the
                        [HYDROGRAPHS] section.
           SewerArea    area of the sewershed which contributes RDII to the node (acres or
                        hectares).
                                        332

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Section:    [HYDROGRAPHS]

Purpose:   Specifies the shapes of the triangular unit hydrographs that determine the amount of
           rainfall-dependent infiltration/inflow (RDM) entering the drainage system.

Formats:   Name   Raingage
           Name   Month  SHORT/MEDIUM/LONG   R   T  K  (Dmax  Dree DO)
Remarks:  Name
           Raingage
           Month

           R
           T

           K

           Dmax
           Dree

           DO
name assigned to a unit hydrograph group.
name of the rain gage used by the unit hydrograph group.
month of the year (e.g., JAN, FEE, etc. or ALL for all months).
response ratio for the unit hydrograph.
time to peak (hours) for the unit hydrograph.
recession limb ratio for the unit hydrograph.
maximum initial abstraction depth available (in rain depth units).
initial abstraction recovery rate (in  rain depth units per day)
initial abstraction depth already filled at the start of the simulation (in
rain depth units).
           For each group of unit hydrographs, use one line to specify its rain gage followed by
           as many  lines as are needed to define each unit hydrograph  used by the group
           throughout the year. Three separate unit hydrographs, that represent the short-term,
           medium-term, and long-term RDM responses, can be defined for each month (or all
           months taken together). Months not listed are assumed to have no RDM.

           The response ratio (R) is the fraction of a  unit of rainfall  depth that becomes RDM.
           The sum of the ratios for a set of three hydrographs does not have to equal 1.0.

           The recession limb ratio (K) is the ratio of the duration of the hydrograph's recession
           limb to the time to peak (T) making the hydrograph time base equal to T*(1+K) hours.
           The area under each unit hydrograph is 1  inch (or mm).

           The optional initial abstraction parameters determine  how much rainfall is lost at the
           start  of a storm to interception  and depression  storage. If not supplied then the
           default is no initial abstraction.

Examples: ; All three unit hydrographs in this group have the same shapes except those in July,
           ; which  have only a short- and medium-term response and  a different shape.
           UH101   RG1
           UH101   ALL SHORT  0.033 1.0  2.0
           UH101   ALL MEDIUM 0.300 3.0  2.0
           UH101   ALL LONG    0.033 10.0  2.0
           UH101   JUL SHORT  0.033 0.5  2.0
           UH101   JUL MEDIUM 0.011 2.0  2.0
                                         333

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Section:   [CURVES]
Purpose:  Describes a relationship between two variables in tabular format.

Format:   Name   Type  X-value   Y-value   . . .

Remarks:  JVame      name assigned to table
          Type      STORAGE / SHAPE /  DIVERSION /  TIDAL  /  PUMPI  / PUMP2 /
                     PUMPS / PUMP4 / RATING  /  CONTROL
          x-value   an x (independent variable) value
          r-value   the y (dependent variable) value corresponding to x

          Multiple pairs of x-y values can appear on a line. If more than one line is needed,
          repeat the curve's name (but not the type) on subsequent lines. The x-values must
          be entered in increasing order.

          Choices for curve type have the following meanings (flows are expressed in the
          user's choice of flow units set in the [OPTIONS] section):
              STORAGE      surface area in ft2 (m2) v. depth in ft (m) for a storage unit node
              SHAPE        width v. depth for a custom closed cross-section, both
                            normalized with respect to full depth
              DIVERSION    diverted outflow v. total inflow for a flow divider node
              TIDAL        water surface elevation in ft (m) v. hour of the day for an outfall
                            node
              PUMPI        pump outflow v. increment of inlet node volume in ft3 (m3)
              PUMP2        pump outflow v. increment of inlet node depth  in ft (m)
              PUMPS        pump outflow v. head difference between outlet and inlet nodes
                            in ft (m)
              PUMP4        pump outflow v. continuous depth in ft (m)
              RATING       outlet flow v. head in ft (m)
              CONTROL      control setting v. controller variable
          See Section 3.2 for illustrations of the different types of pump curves.

Examples: ; Storage curve  (x  =  depth,  y =  surface  area)
          AC1  STORAGE   0  1000   2   2000   4   3500   6  4200    8   5000

          ;Typel pump curve  (x  = inlet wet well volume,  y =  flow )
          PCI  PUMPI
          PCI  100  5  300   10   500   20
                                        334

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Section:    [TIMESERIES]

Purpose:   Describes how a quantity varies over time.

Formats:   Name   ( Date )   Hour   Value
           Name   Time   Value  ...
           Name   FILE   Fname
Remarks:  Name

           Date


           Hour



           Time


           Value

           Fname
name assigned to time series.
date in Month/Day/Year format (e.g., June 15, 2001 would be
6/15/2001).
24-hour military time (e.g., 8:40 pm would be 20:40) relative to the last
date specified (or to midnight of the starting date of the simulation if no
previous date was specified).
hours since the start of the simulation, expressed as a decimal number
or as hours:minutes.
value corresponding to given date and time.
name of a file in which the time series data are stored
           There are two options for supplying the data for a time series:
           i. directly within this input file section as described by the first two formats
           ii. through an external data file named with the third format.

           When direct  data entry  is used, multiple date-time-value or time-value entries can
           appear on a line. If more than one line is needed, the table's name must be repeated
           as the first entry on subsequent lines.

           When an external file is  used, each line in the file must use the same formats listed
           above, except that only one date-time-value (or time-value) entry is allowed per line.
           Any line that begins with a semicolon is considered a comment line and is ignored.
           Blank lines are not allowed.

           Note that there are  two  methods for describing the occurrence time of time series
           data:
              as calendar date/time of day (which requires that at least one date, at the start of
              the series, be entered)
              as elapsed hours since the start of the simulation.
           For the first method, dates need only be entered at points in  time when a new day
           occurs.

Examples:  ; Rainfall  time  series with  dates  specified
           TS1  6-15-2001 7:00   0.1   8:00  0.2   9:00  0.05   10:00  0
           TS1  6-21-2001 4:00   0.2   5:00  0    14:00  0.1    15:00  0
                                         335

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;Inflow hydrograph - time relative to start of simulation
HY1  0  0  1.25 100  2:30 150  3.0 120  4.5 0
HY1  32:10 0  34.0 57  35.33 85  48.67 24  50 0
                          336

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Section:   [PATTERNS]
Purpose:  Specifies time pattern of dry weather flow or quality in the form of adjustment factors
          applied as multipliers to baseline values.
Format:
          Name  MONTHLY
          Name  DAILY
          Name  HOURLY
          Name  WEEKEND
Factorl  Factor2
Factorl  Factor2
Factorl  Factor2
Factorl  Factor2
Factorl2
Factor?
Factor24
Factor24
Remarks:  Name      name used to identify the pattern.
          Factorl,
          Fact or 2,
          etc.        multiplier values.

          The  MONTHLY format is used to set monthly pattern factors for dry weather flow
          constituents.

          The  DAILY format is used to set dry weather pattern factors for each day of the
          week, where Sunday is day 1.

          The  HOURLY format  is used to  set dry weather factors for each hour of the day
          starting from midnight. If these factors are different for weekend days than for
          weekday  days then the WEEKEND format can be used to specify hourly adjustment
          factors just for weekends.
          More than one line can be used to enter a pattern's factors by repeating the pattern's
          name (but not the pattern type) at the beginning of each additional line.
          The  pattern factors are applied as multipliers to any baseline dry weather flows  or
          quality concentrations supplied in the [DWF] section.

Examples: ;  Day of  week adjustment  factors
          Dl   DAILY  0.5   1.0   1.0   1.0   1.0   1.0    0.5
          D2   DAILY  0.8   0.9   1.0   1.1   1.0   0.9    0.8
          ;  Hourly  adjustment  factors
          HI  HOURLY  0.5 0.6  0.7  0.8  0.8  0.9
          HI           1.1 1.2  1.3  1.5  1.1  1.0
          HI           0.90.80.70.60.50.5
          HI           0.5 0.5  0.5  0.5  0.5  0.5
                                        337

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D3.    Map Data Section

SWMM's graphical user interface (GUI) can display a schematic map of the drainage area being
analyzed. This map displays subcatchments as polygons, nodes as circles, links as polylines, and
rain gages as bitmap symbols. In addition it can display text labels and a backdrop image, such
as a street map.  The GUI  has tools for drawing, editing, moving, and displaying these map
elements. The map's coordinate data are stored in the format described below.  Normally these
data are simply appended to the SWMM input file by the GUI so  users do not have to concern
themselves with it. However it is sometimes more convenient to import map data from some other
source, such as a  CAD or CIS file, rather than drawing a map from scratch using  the GUI. In this
case the data can be added to the SWMM project  file using any text editor  or spreadsheet
program. SWMM  does  not  provide  any automated facility for converting coordinate data from
other file formats into the SWMM map data format.

SWMM's map data are organized into the following seven sections:
    [MAP]
    [POLYGONS]
    [COORDINATES]
    [VERTICES]
    [LABELS]
    [SYMBOLS]
    [BACKDROP]
X,Y coordinates of the map's bounding rectangle
X,Y coordinates for each vertex of subcatchment polygons
X,Y coordinates for nodes
X,Y coordinates for each interior vertex of polyline links
X,Y coordinates and text of labels
X,Y coordinates for rain  gages
X,Y coordinates of the bounding rectangle and file name of the backdrop
image.
Figure D-2 displays a sample map and Figure D-3 the data that describes it. Note that only one
link, 3, has interior vertices which give it a curved shape. Also observe that this map's coordinate
system has no units, so that the positions of its objects may not necessarily coincide to their real-
world locations.
                          Figure D-2 Example study area map
                                          338

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  [MAP]
   DIMENSIONS
   UNITS

  [COORDINATES]
  ;/Node
   Nl
   N2
   N3
   N4

  [VERTICES]
  ; /Link
   3
   3

  [SYMBOLS]
  ;;Gage
   Gl

  [Polygons]
  ;;Subcatchment
   SI
   SI
   SI
0.00   0.00
None
   X-Coord
   4006.62
   6953.64
   4635.76
   8509.93
   X-Coord
   5430.46
   7251.66
   X-Coord
   5298.01
   X-Coord
   3708.61
   4834.44
   3675.50
              10000.00  10000.00
Y-Coord
5463.58
4768.21
3443.71
827.81
Y-Coord
2019.87
927.15
Y-Coord
9139.07
Y-Coord
8543.05
7019.87
4834.44
  <  additional vertices not listed >
   S2                  6523.18          8079.47
   S2                  8112.58          8841.06
                     Figure D-3 Data for example study area map

A detailed description of each map data section will now be given. Remember that map data are
only used as a visualization aid for SWMM's GUI and they play no role in any of the  runoff or
routing computations. Map data are not needed for running the command line version of SWMM.
                                       339

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Section:   [MAP]

Purpose:   Provides dimensions and distance units for the map.

Formats:   DIMENSIONS  xi  Yl X2 Y2
           UNITS        FEET /  METERS / DEGREES / NONE

Remarks:  xi         lower-left X coordinate of full map extent
           Yl         lower-left Y coordinate of full map extent
           X2         upper-right X coordinate of full map extent
           Y2         upper-right Y coordinate of full map extent


Section:   [COORDINATES]

Purpose:   Assigns X,Y coordinates to drainage system nodes.

Format:    Node  Xcoord   Ycoord

Remarks:  Node      name of node.
           Xcoord    horizontal coordinate relative to origin in lower left of map.
           Ycoord    vertical coordinate relative to origin in lower left of map.


Section:   [VERTICES]

Purpose:   Assigns X,Y coordinates to interior vertex points of curved drainage system links.

Format:    Link  Xcoord   Ycoord

Remarks:  Link      name of link.
           Xcoord    horizontal coordinate of vertex relative to origin in lower left of map.
           Ycoord    vertical coordinate of vertex relative to origin in  lower left of map.

           Include a separate line for each interior vertex of the link, ordered from the inlet node
           to the outlet node.

           Straight-line links have no interior vertices and therefore are not listed in this section.
                                          340

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Section:    [POLYGONS]

Purpose:   Assigns X,Y coordinates to vertex points of polygons that define a subcatchment
           boundary.

Format:    Subcat   Xcoord   Ycoord

Remarks:   Subcat    name of subcatchment.
           Xcoord    horizontal coordinate of vertex relative to origin in lower left of map.
           Ycoord    vertical coordinate of vertex relative to origin in lower left of map.

           Include a separate line for each vertex of the subcatchment polygon, ordered in a
           consistent clockwise or counter-clockwise sequence.
Section:    [SYMBOLS]

Purpose:   Assigns X,Y coordinates to rain gage symbols.

Format:    Gage   Xcoord  Ycoord

Remarks:   Gage      name of rain gage.
           Xcoord   horizontal coordinate relative to origin in lower left of map.
           Ycoord   vertical coordinate relative to origin in lower left of map.
Section:    [LABELS]

Purpose:   Assigns X,Y coordinates to user-defined map labels.

Format:    Xcoord  Ycoord   Label  (Anchor  Font  Size  Bold  Italic)

Remarks:   Xcoord   horizontal coordinate relative to origin in lower left of map.
           Ycoord   vertical coordinate relative to origin in lower left of map.
           Label     text of label surrounded by double quotes.
           Anchor   name of node or subcatchment that anchors the label on zoom-ins (use
                     an empty pair of double quotes if there is no anchor).
           Font      name of label's font (surround by double quotes if the font name includes
                     spaces).
           size      font size in points.
           Bold      YES for bold font, NO otherwise.
           italic   YES for italic font, NO otherwise.
                                         341

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           Use of the anchor node feature will prevent the label from moving outside the viewing
           area when the map is zoomed in on.

           If no font information is provided then a default font is used to draw the label.
Section:    [BACKDROP]

Purpose:   Specifies file name and coordinates of map's backdrop image.

Formats:   FILE          Fname
           DIMENSIONS   XI Yl X2 Y2
Remarks:  Fname
           XI
           Yl
           X2
           Y2
name of file containing backdrop image
lower-left X coordinate of backdrop image
lower-left  Y coordinate of backdrop image
upper-right X coordinate  of backdrop image
upper-right Y coordinate  of backdrop image
                                         342

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          APPENDIX E - ERROR AND WARNING MESSAGES
ERROR 101:   memory allocation error.
             There is not enough physical memory in the computer to analyze the study area.

ERROR 103:   cannot solve KW equations for Link xxx.
             The  internal solver for Kinematic Wave routing failed to  converge  for the
             specified link at some stage of the simulation.

ERROR 105:   cannot open ODE solver.
             The system could not open its Ordinary Differential Equation solver.

ERROR 107:   cannot compute a valid time step.
             A valid time step for runoff or flow routing  calculations  (i.e.,  a number greater
             than 0) could not be computed at some stage of the simulation.

ERROR 108:   ambiguous outlet ID name for Subcatchment xxx.
             The  name of the element identified as the outlet of a subcatchment belongs to
             both a node and a subcatchment in the project's data base.

ERROR 109:   invalid parameter values for Aquifer xxx.
             The  properties entered for an aquifer object were either invalid numbers  or were
             inconsistent with one another (e.g., the soil field capacity was higher than the
             porosity).

ERROR 110:   ground elevation is below water table for Subcatchment xxx.
             The  ground elevation assigned to a  subcatchment's  groundwater parameters
             cannot be below the initial water table  elevation of the aquifer object used by the
             subcatchment.

ERROR 111:   invalid length for Conduit xxx.
             Conduits cannot have zero or negative lengths.

ERROR 113:   invalid roughness for Conduit xxx.
             Conduits cannot have zero or negative roughness values.

ERROR 114:   invalid number of barrels for Conduit xxx.
             Conduits must consist of one or more barrels.

ERROR 115:   adverse slope for Conduit xxx.
             Under Steady or Kinematic Wave routing, all conduits must have positive slopes.
             This can usually be  corrected  by reversing the inlet and outlet  nodes of the
             conduit (i.e., right click on the conduit  and select Reverse from the popup menu
             that appears). Adverse slopes are permitted under Dynamic Wave routing.
                                       343

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ERROR 117:   no cross section defined for Link xxx.
              Cross section geometry was never defined for the specified link.

ERROR 119:   invalid cross section for Link xxx.
              Either an invalid shape  or invalid set of dimensions was specified for a  link's
              cross section.

ERROR 121:   missing or invalid pump curve assigned to Pump xxx.
              Either no pump curve or an invalid type of curve was specified for a pump.

ERROR 131:   the following links form cyclic loops in the drainage system.
              The Steady and Kinematic Wave flow  routing methods cannot  be applied to
              systems where a cyclic loop exists (i.e.,  a directed path along a set of links that
              begins and ends at the same node). Most often the cyclic nature of the loop can
              be eliminated by reversing the direction of one of its links (i.e., switching the inlet
              and outlet  nodes of the  link). The names of the links that form the loop will  be
              listed following this message.

ERROR 133:   Node xxx has more than one outlet link.
              Under Steady and Kinematic Wave flow routing, a junction node can have only a
              single outlet link.

ERROR 134:   Node xxx has illegal DUMMY link connections.
              Only a  single conduit with a DUMMY cross-section or Ideal-type pump can  be
              directed out of  a node;  a node  with an outgoing Dummy conduit or Ideal pump
              cannot  have all of its incoming links be Dummy conduits and Ideal pumps; a
              Dummy conduit cannot have its upstream end connected to a storage node.

ERROR 135:   Divider xxx does not have two outlet links.
              Flow divider nodes must have two outlet links connected to them.

ERROR 136:   Divider xxx has invalid  diversion link.
              The link specified as  being the one carrying the diverted flow from a flow divider
              node was defined with a different inlet node.

ERROR 137:   Weir Divider xxx has invalid parameters.
              The parameters of a Weir-type divider node either are  non-positive numbers or
              are inconsistent (i.e., the value of the discharge coefficient times the weir height
              raised to the 3/2 power must be greater than the minimum flow parameter).

ERROR 138:   Node xxx has initial depth greater than maximum depth.
              Self-explanatory.

ERROR 139:   Regulator xxx  is the outlet of a non-storage node.
              Under Steady or Kinematic Wave flow routing, orifices, weirs, and outlet links can
              only be used as outflow links from storage nodes.
                                        344

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ERROR 141:   Outfall xxx has more than 1 inlet link or an outlet link.
              An outfall node is only permitted to have one link attached to it.

ERROR 143:   Regulator xxx has invalid cross-section shape.
              An orifice must have either a CIRCULAR or RECT_CLOSED shape, while a weir
              must have either a RECTJDPEN, TRAPEZOIDAL, or TRIANGULAR shape.

ERROR 145:   Drainage system has no acceptable outlet nodes.
              Under Dynamic Wave flow routing, there must be at least one node designated
              as an outfall.

ERROR 151:   a Unit Hydrograph in set xxx has invalid time base.
              The  time base of a Unit Hydrograph cannot be negative and if positive, must not
              be less than the recording interval for its rain gage.

ERROR 153:   a Unit Hydrograph in set xxx has invalid response ratios.
              The  response ratios for a set of Unit Hydrographs (the short-, medium-, and long-
              term response hydrographs) must be between 0 and 1.0 and cannot add up to a
              value greater than 1.0

ERROR 155:   invalid sewer area for RDM at Node xxx.
              The  sewer area contributing RDM inflow to a node cannot be a negative number.

ERROR 156:   inconsistent data file name for Rain Gage xxx.
              If two Rain Gages use files for their data sources and have the same Station IDs
              then they must also use the same data files.

ERROR 157:   inconsistent rainfall format for Rain Gage xxx.
              If two or more rain gages  use the same Time Series for their  rainfall data then
              they must all use the same data format (intensity,  volume, or cumulative volume).

ERROR 158:   time series for Rain Gage xxx is also used by another object.
              A rainfall Time Series associated with a Rain Gage cannot be used by another
              object that is not also a Rain Gage.

ERROR 159:   recording interval greater than time series interval for Rain Gage xxx.
              The  recording time interval specified for the rain gage is greater than the smallest
              time interval between values in the Time Series used by the gage.

ERROR 161:   cyclic dependency in treatment functions at Node xxx.
              An example would be where the  removal of pollutant 1 is defined as a function of
              the removal of pollutant 2 while the removal of pollutant 2 is defined as a function
              of the removal of pollutant 1.

ERROR 171:   Curve xxx has invalid or out of sequence data.
              The  X-values of a curve object must be entered in increasing order.
                                        345

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ERROR 173:   Time Series xxx has its data out of sequence.
              The time (or date/time) values of a time series must be entered  in sequential
              order.

ERROR 181:   invalid Snow Melt Climatology parameters.
              The ATI Weight or Negative Melt Ratio parameters are not between 0 and 1 or
              the site latitude is not between -60 and +60 degrees.

ERROR 182:   invalid parameters for Snow Pack xxx.
              A snow pack's minimum melt coefficient is greater than its maximum coefficient;
              the fractions of free water capacity or impervious plowable area are not between
              0 and 1; or the snow removal fractions sum to more than 1.0.

ERROR 183:   no type specified for LID xxx.
              A named LID control has layers  defined for it  but its  LID  type was  never
              specified.

ERROR 184:   missing layer for LID xxx.
              A required design layer is missing for the specified LID control.

ERROR 185:   invalid parameter value for LID xxx.
              An invalid value was supplied for an LID control's design parameter.

ERROR 187:   LID area exceeds total area for Subcatchment xxx.
              The area of the LID controls placed within the subcatchment is  greater than that
              of the subcatchment itself.

ERROR 188:   LID capture area exceeds total impervious area for Subcatchment xxx.
              The amount of impervious  area  assigned to  be treated by LID controls in the
              subcatchment exceeds the total amount of impervious area available.

ERROR 191:   simulation start date comes after ending date.
              Self-explanatory.

ERROR 193:   report start date comes after ending date.
              Self-explanatory.

ERROR 195:   reporting time step is less than routing time step.
              Self-explanatory.

ERROR 200:   one or more errors  in input file.
              This message appears when one or more input file parsing errors (the 200-series
              errors) occur.

ERROR 201:   too many characters in input line.
              A line in the input file cannot exceed 1024 characters.
                                        346

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ERROR 203:   too few items at line n of input file.
              Not enough data items were supplied on a line of the input file.

ERROR 205:   invalid keyword at line n of input file.
              An unrecognized keyword was encountered when parsing a line of the input file.

ERROR 207:   duplicate ID name at line n of input file.
              An ID name  used  for an object was already assigned to an object of the same
              category.

ERROR 209:   undefined object xxx at line n of input file.
              A reference was made to an object that was  never defined. An example would be
              if node 123 were designated as the outlet point of a subcatchment, yet no such
              node was ever defined in the study area.

ERROR 211:   invalid number xxx at line n of input file.
              Either a string value was encountered where a numerical value was expected or
              an invalid number (e.g., a  negative value) was supplied.

ERROR 213:   invalid date/time xxx at line n of input file.
              An invalid format for a date or time was encountered. Dates must be entered as
              month/day/year and times as either decimal hours or as hour:minute:second.

ERROR 217:   control rule clause out of sequence at line n of input file.
              Errors of this nature can  occur when the format for writing control rules is not
              followed correctly (see Section C.3).

ERROR 219:   data provided for unidentified transect at line n of input file.
              A GR  line with Station-Elevation data was encountered in the  [TRANSECTS]
              section of the input file after an NC line but  before any X1 line  that contains the
              transect's ID  name.

ERROR 221:   transect station out of sequence at line n of input file.
              The station distances specified for the transect of an irregular cross section must
              be in increasing numerical order starting from the left bank.

ERROR 223:   Transect xxx has too few stations.
              A transect for an irregular cross section must have at least 2 stations defined for
              it.

ERROR 225:   Transect xxx has too many stations.
              A transect cannot have more than 1500 stations defined for it.

ERROR 227:   Transect xxx has  no Manning's  N.
              No Manning's N was specified for a transect (i.e., there was no NC line in the
              [TRANSECTS] section of the input file.
                                         347

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ERROR 229:   Transect xxx has invalid overbank locations.
              The distance values specified for either the left or right overbank locations of a
              transect do not match any of the distances listed for the transect's stations.

ERROR 231:   Transect xxx has no depth.
              All of the stations for a transect were assigned the same elevation.

ERROR 233:   invalid treatment function expression at line  n of input file.
              A treatment function  supplied for a pollutant at a specific node is either not a
              correctly formed  mathematical  expression  or refers to  unknown  pollutants,
              process variables, or math functions.

ERROR 301:   files share same names.
              The input, report,  and binary output files specified on the  command line cannot
              have the same names.

ERROR 303:   cannot open input file.
              The input file either does not exist or cannot be opened (e.g., it might be in use
              by another program).

ERROR 305:   cannot open report file.
              The report file cannot be opened (e.g., it might  reside in a directory to which the
              user does not have write privileges).

ERROR 307:   cannot open binary results file.
              The binary output file cannot be  opened (e.g., it might reside in a directory to
              which the user does not have write privileges).

ERROR 309:   error writing to binary  results file.
              There was an error in trying to write results to the  binary output file (e.g., the disk
              might be full or the file size exceeds the limit imposed by the operating  system).

ERROR 311:   error reading from binary results file.
              The command line version of SWMM could  not read results saved to the binary
              output file when writing results to the report file.

ERROR 313:   cannot open scratch rainfall interface file.
              SWMM  could not open the  temporary file it uses to collate data together from
              external rainfall files.

ERROR 315:   cannot open rainfall interface file xxx.
              SWMM  could not open the specified  rainfall interface file, possibly  because it
              does not exist or because the user does not have write privileges to its directory.
                                         348

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ERROR 317:   cannot open rainfall data file xxx.
              An external rainfall data file could not be opened, most likely because it does not
              exist.

ERROR 318:   date out of sequence in rainfall data file xxx.
              An external user-prepared rainfall data file must  have its entries appear in
              chronological order. The first out-of-order entry will be listed.

ERROR 319:   unknown format for rainfall data file.
              SWMM could not recognize the format used for a designated rainfall data file.

ERROR 320:   invalid format for rainfall  interface file.
              SWMM was trying to read data from a designated rainfall interface file with the
              wrong format (i.e., it may have been created for some other project or actually be
              some other type of file).

ERROR 321:   no data in rainfall interface file for gage xxx.
              This message occurs when  a  project wants to use  a previously  saved  rainfall
              interface file, but cannot find any data for one of its  rain gages in the interface
              file. It can also occur if the gage uses data  from a user-prepared rainfall file and
              the station id entered for the gage cannot be found in the file.

ERROR 323:   cannot open runoff interface file xxx.
              A runoff interface file could not be opened,  possibly because it does not exist or
              because the user does not have write privileges to its directory.

ERROR 325:   incompatible data found in runoff interface file.
              SWMM was trying to read data from a designated runoff interface file with the
              wrong format (i.e., it may have been created for some other project or actually be
              some other type of file).

ERROR 327:   attempting to read beyond end of runoff interface file.
              This error can occur when a previously saved runoff interface file is being used in
              a simulation with a longer duration than the one that created the interface file.

ERROR 329:   error in reading from runoff interface file.
              A format error was encountered while trying to read data from a previously saved
              runoff interface file.

ERROR 331:   cannot open hot start interface file xxx.
              A hot start interface file could not be opened, possibly because it does not exist
              or because the user does not have write privileges to its directory.

ERROR 333:   incompatible data found in hot start interface file.
              SWMM was trying to read  data from a designated hot start interface file with the
              wrong format (i.e., it may have been created for some other project or actually be
              some other type of file).
                                          349

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ERROR 335:   error in reading from hot start interface file.
              A format error was encountered while trying to read data from a previously saved
              hot start interface file.

ERROR 336:   no climate file specified for evaporation and/or wind speed.
              This  error occurs when the user specifies that  evaporation or wind speed data
              will be read from an external climate file, but no name is supplied for the file.

ERROR 337:   cannot open climate file xxx.
              An external climate data file could not be opened, most likely because it does not
              exist.

ERROR 338:   error in reading from climate file xxx.
              SWMM  was trying to  read data from  an external climate file with the  wrong
              format.

ERROR 339:   attempt to read beyond end  of climate file xxx.
              The specified external climate does not include  data for the period of time being
              simulated.

ERROR 341:   cannot open scratch RDM interface file.
              SWMM could not open the temporary file it uses to store RDM flow data.

ERROR 343:   cannot open RDM interface file xxx.
              An RDM interface file could not be opened, possibly because it does not exist or
              because the  user does  not have write privileges to its directory.

ERROR 345:   invalid format for RDM interface file.
              SWMM  was trying to read data from  a designated RDM interface file with the
              wrong format (i.e., it may have been created for some other project or actually be
              some other type of file).

ERROR 351:   cannot open routing interface file xxx.
              A routing interface file could not be opened, possibly because it does not exist or
              because the  user does  not have write privileges to its directory.

ERROR 353:   invalid format for routing interface file xxx.
              SWMM was  trying to read data from a  designated routing  interface file with the
              wrong format (i.e., it may have been created for some other project or actually be
              some other type of file).

ERROR 355:   mismatched names in routing interface file xxx.
              The names of pollutants found in a designated routing interface file do not match
              the names used in the current project.
                                         350

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ERROR 357:   inflows and outflows interface files have same name.
              In cases where a run uses one routing interface file to provide inflows for a set of
              locations and another to save outflow results, the two files cannot both have the
              same name.

ERROR 361:   could not open external file used for Time Series xxx.
              The external file used to provide data for the named time series could not be
              opened, most likely because it does not exist.

ERROR 363:   invalid data in external file used for used for Time Series xxx.
              The external file used to provide data for the named time series has one or more
              lines with the wrong format.

WARNING 01:  wet weather time step reduced to recording interval for Rain Gage xxx.
              The wet weather time  step was  automatically  reduced  so that no  period with
              rainfall would be skipped during a simulation.

WARNING 02:  maximum depth increased for Node xxx.
              The maximum depth for the node was automatically increased to match the top
              of the highest connecting conduit.

WARNING 03:  negative offset ignored for Link  xxx.
              The link's stipulated offset was below the connecting node's  invert so its  actual
              offset was set to 0.

WARNING 04:  minimum elevation drop used for Conduit xxx.
              The elevation drop between the end nodes of the conduit was below 0.001 ft
              (0.00035 m) so the latter value was used instead to  calculate its slope.

WARNING 05:  minimum slope used for Conduit xxx.
              The conduit's computed slope was below the  user-specified Minimum Conduit
              Slope so the latter value was used instead.

WARNING 06:  dry weather time step increased to wet weather time step.
              The user-specified time step for computing runoff during dry weather periods was
              lower than that set for wet weather periods  and was automatically increased to
              the wet weather value.

WARNING 07:  routing time step reduced to wet weather time step.
              The user-specified time step for flow routing was  larger than the wet weather
              runoff time step and was automatically reduced to the runoff time step to prevent
              loss of accuracy.
                                        351

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WARNING 08: elevation drop exceeds length for Conduit xxx.
              The elevation drop across the ends of a conduit exceeds its length. The program
              computes the conduit's slope as the elevation drop divided by the length instead
              of using the more accurate right triangle method. The user should  check for
              errors in the length and in  both the invert elevations and offsets at the conduit's
              upstream and downstream nodes.

WARNING 09: time series interval greater than recording interval for Rain Gage xxx.
              The smallest time interval between entries in the precipitation time series used by
              the rain gage is greater than the recording time interval specified for the gage. If
              this  was not  actually  intended then what appear to be  continuous periods of
              rainfall in the time series will instead be read with time gaps in between them.

WARNING 10: crest elevation is below downstream invert for regulator Link xxx.
              The height of the opening on  an orifice, weir,  or outlet  is below  the invert
              elevation of its  downstream node. Users should check to see if the regulator's
              offset height or the downstream node's invert elevation is in error.

WARNING 11: non-matching attributes in Control Rule xxx.
              The premise  of a control is comparing two  different types  of attributes to one
              another (for example, conduit flow and junction water depth).
                                          352

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