EPA/600/R-18/282 | September 2018
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
oEPA
Survey and Assessment of Fate and
Transport Models for Use Following
a Wide-Area Urban Release to
Inform Mapping, Characterization,
and Site Clearance
Office of Research and Development
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EPA/600/R-18/282
September 2018
Survey and Assessment of Fate and
Transport Models for Use Following a Wide-
Area Urban Release to Inform Mapping,
Characterization, and Site Clearance
by
Limin Chen and Sujoy Roy
Tetra Tech
Lafayette, CA 94549
Timothy Boe and Anne Mikelonis
U.S. Environmental Protection Agency
Office of Research and Development
National Homeland Security Research Center
Decontamination and Consequence Management Division
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Disclaimer
The U.S. Environmental Protection Agency (EPA) through its Office of Research and
Development funded and managed the research described herein under EP-C-15-004, PR-ORD-
16-01029 to Tetra Tech. It has been subjected to the Agency's review and has been approved for
publication. Note that approval does not signify that the contents necessarily reflect the views of
the Agency. Any mention of trade names, products, or services does not imply an endorsement
by the U.S. Government or EPA. The EPA does not endorse any commercial products, services,
or enterprises. The contractor role did not include establishing Agency policy.
Questions concerning this document or its application should be addressed to:
Anne Mikelonis, Ph.D., P.E.
U.S. Environmental Protection Agency
Office of Research and Development
National Homeland Security Research Center
Decontamination and Consequence Management Division
109 T.W. Alexander Dr. (MD-E-343-06)
Research Triangle Park, NC 27711
Phone 919-541-0579
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Table of Contents
1.0 Introduction 1
2.0 Background 1
3.0 Model Review Process 2
3.1 Initial Screening 2
3.2 Detailed Review and Quality Assurance 3
4.0 Results of Model Review 6
4.1 SWMM Family of Models 6
4.2 S ewershed and S ewer Network Model s 7
4.3 Watershed Model s 7
5.0 Discussion 7
6.0 References 9
Appendix A - Models in Initial Screening 13
Appendix B - Model Summaries 20
B. 1 BASINS (Better Assessment Science Integrating point and Non-point Sources) 22
B.2 BasinSim 1.0 23
B.3 Civil Storm 24
B.4 GWLF (Generalized Watershed Loading Function) 25
B.5 GSSHA (Gridded Surface Subsurface Hydrologic Analysis) 26
B.6 HEC-HMS (Hydrologic Engineering Center-Hydrologic Modeling System) 27
B.7 HSPF (Hydrological Simulation Program Fortran) 28
B.8 HydroCAD 30
B.9 Info SWMM 31
B.10 InfoWorks ICM (InfoWorks Integrated Catchment Modeling) 33
B. 11 LSPC (Loading Simulation Program in C++) 34
B.12 MapShed 35
B. 13 MIDS (Minimal Impact Design Standards) calculator 36
B.14 Mike Urban 37
B. 15 P8 (Program for Predicting Polluting Particle Passage through Pits, Puddles, and Ponds) 39
B.16 PC SWMM 40
B. 17 SELDM (Stochastic Empirical Loading and Dilution Model) 41
B.18 SELECT (BMP System Effectiveness and Life-Cycle Evaluation of Costs Tool) 42
B. 19 SHSAM (Sizing Hydrodynamic Separators and Manholes) 43
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B.20 STEPL 44
B.21 Storm \ IT 45
B.22 SWAT (Soil and Water Assessment Tool) 46
B.23 SWMM5 (Storm Water Management Model) 48
B.24 WARMF (Watershed Analysis Risk Management Framework) 50
B.25 WinSLAMM (Source Loading and Management Model) 52
B.26 XPSWMM 54
List of Tables
Table 1: Explanation of stormwater model survey evaluation criteria 5
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Acronyms and Abbreviations
API Application Programming Interface
ARM Agricultural Runoff Management
ARS USDA Agricultural Research Service
BMP Best Management Practice
BOD Biochemical Oxygen Demand
CAD Computer-Aided Design
CSO Combined Sewer Overflow
CSS Conduit Storage Synthesizer
CSV Comma Separated Values
Cu Copper
DCMD EPA Decontamination and Consequence Management Division
DEM Digital Elevation Model
DNR Department of Natural Resources
EMC Event Mean Concentration
EPA United States Environmental Protection Agency
FEMA Federal Emergency Management Agency
FHWA Federal Highway Administration
GenScn A tool for the generation and analysis of model simulation scenarios for watersheds
GIS Geographic Information System
HEC-RAS Hydrologic Engineering Center - River Analysis System
HSP Hydrological Simulation Program
HSPExp Expert System for Calibration of HSPF
HSPF Hydrologic Simulation Program Fortran
HSRP EPA Homeland Security Research Program
IMAAC Interagency Modeling and Atmospheric Assessment Center
LID Low Impact Development
LSPC Loading Simulation Program in C++
MPCA Minnesota Pollution Control Agency
MS Microsoft
N Nitrogen
NERL EPA National Exposure Research Laboratory
NHSRC EPA National Homeland Security Research Center
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NPS Non-point Source
NRCS Natural Resources Conservation Service
NRMRL EPA National Risk Management Research Laboratory
P Phosphorus
Pb Lead
PC Personal Computer
RAM Random Access Memory
RDII Rainfall Derived Inflow and Infiltration
RTC Real-Time Control
SCM Stormwater Control Measure
SCS Soil Conservation Service
SED Systems Exposure Division
SFEM Sewer Flow Estimation Model
SUDS Sustainable Urban Drainage system
SVGA Super Video Graphics Array
SWMM Stormwater Management Model
TKN Total Kj el dahl Nitrogen
TMDL Total Maximum Daily Load
TP Total Phosphorus
TSS Total Suspended Solids
US United States
US ACE United States Army Corps of Engineers
USGS United States Geological Survey
USD A United States Department of Agriculture
VBA Visual Basic for Applications
VIMS Virginia Institute of Marine Science
WDMUtil Tool to create time series data
WiLMS Wisconsin Lake Modeling Suite
WinHSPF Hydrologic Simulation Program for Windows
WSD Water Systems Division
Zn Zinc
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Acknowledgments
Contributions of the following individuals and organizations to this report are gratefully
acknowledged:
EPA Project Team
Timothy Boe, NHSRC/DCMD
M. Worth Calfee, Ph.D., NHSRC/DCMD
Sang Don Lee, Ph.D., NHSRC/DCMD
Anne Mikelonis, Ph.D., P.E., NHSRC/DCMD
Katherine Ratliff, Ph.D., ORISE Postdoctoral Fellow
Tetra Tech Project Team
Limin Chen, Ph.D.
Sujoy Roy, Ph.D.
EPA Technical Reviewers
Michael Pirhalla, NHSRC/DCMD
Michelle Simon, Ph.D., P.E., NRML/WSD
Sean Woznicki, Ph.D., NERL/SED
EPA Technical Edit
Joan Bursey, Ph.D., Grantee, The National Caucus and Center on Black Aged, Inc.
EPA Quality Assurance
Eletha Brady Roberts, NHSRC
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Executive Summary
If a terrorist event, accidental release, or natural disaster causes a wide area of land to be
contaminated with chemical, biological, or radiological particulates, emergency responders need
a rapid way to determine where to sample and decontaminate prior to clearing the area. A
comprehensive storm water model review does not exist that is focused on the needs of those
remediating after such a release. This report summarizes a variety of modeling tools that are used
for understanding the fate and transport of stormwater and associated pollutants in more routine
applications. These existing modeling tools are expected to need modification from their existing
formats to serve the needs of the emergency response and remediation community. Therefore,
criteria specific to emergency response modeling are outlined in Section 3 of this report, and this
report provides two appendices with detailed model information. The criteria include aspects
such as ease of assembly during an emergency event, how prevalent the tools currently are
(which would facilitate model repurposing), and if modifications to the source code are possible
or if the source code is proprietary. In Appendix A, 62 models are characterized, based on their
inclusion of hydrology, hydraulic, and water quality features, and rationale for exclusion is
provided if they were not included in the detailed model summaries. In Appendix B, 26
summaries of models that fit the initial criteria for emergency response modeling are outlined in
further detail, including features, mathematical methods, and license cost.
During the detailed model review, trends in model functionality and original application were
observed. Several proprietary models and specialized frameworks were found to utilize the
United States Environmental Protection Agency's Stormwater Management Model (SWMM)
code to power their simulations. Another cluster of models was established to address design and
operational questions like SWMM but included separately developed computational engines and
accessories. Watershed models formed an additional cluster of models and, in general, were
designed to address runoff pollution loading in a more lumped and wider ecological lens than the
detailed hydraulic resolution of a sewer system. Finally, there was a group of tools that consisted
of simple spreadsheet calculations and were focused on providing a decision support framework
for green infrastructure decisions. These tools tended to lack the mathematical complexities and
detail of the other models.
Overall, no one model was found to include all the components necessary for time-sensitive
stormwater modeling during an emergency such as a widespread biological or radiological
particulate release. However, the SWMM family of models was determined to have the most
promising potential for expansion to emergency response applications due to the open source
core engine code and widespread use. The other proprietary models were also found to include
2D modeling capabilities that could be used to determine the fate and transport of pollutants.
Ultimately, local utilities will need to repurpose and expand their existing stormwater models to
aid in protecting human health and the environment from release of biological, chemical, and
radiological releases.
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1.0 Introduction
This stormwater model review is part of a broader research effort by the Homeland Security
Research Program (HSRP) of the U.S. Environmental Protection Agency's (EPA's) National
Homeland Security Research Center (NHSRC), studying the fate and transport of contaminants
that are deliberately or accidentally released into an urban environment. Under circumstances
where hazardous agents contaminate a large urban area, modeling tools offer decision makers
insight on where to focus sampling and decontamination efforts. For example, when the River
Street warehouse fire occurred in Portland in May 2017 asbestos-containing debris was released
from the fire and air dispersion modeling results were used to inform selection of sampling
locations in the city. This modeling was rapidly available through the Federal Emergency
Management Agency's (FEMA's) Interagency Modeling and Atmospheric Assessment Center
(IMAAC) which provides 24/7 plume modeling support to state, local, and federal officials
involving significant hazardous atmospheric releases. While a wide variety of stormwater tools
are actively used in the urban planning and regulatory sectors for flood water control and water
quality management, the use of water modeling tools during emergency response is relatively
rare (e.g. metals transport in the San Juan River after the Gold King Mine spill) compared to
atmospheric models. Many factors contribute to this air-water-emergency modeling disconnect,
including the need for more cross jurisdictional infrastructure data (e.g., pipe networks) and the
lack of a federally managed modeling center such as the IMAAC. Since a standard resource for
using stormwater models during an emergency response has not been established, many different
modeling tools may be recommended for use during an incident. One objective of this report is
to identify and better understand the diverse landscape of modeling tools that adequately
represent—or can be modified to represent—the transport of substances analogous to particulate-
bound radiological and biological contaminants in stormwater and on urban surfaces (e.g.,
roadways and parks). An additional objective is that the model summaries supplied in Appendix
B provide a quick reference for those new to stormwater modeling or well versed in only a few
models. The summaries are intended to facilitate communication between sectors and assist
emergency response project managers in selecting a useful stormwater model during response
and recovery.
2.0 Background
Stormwater is a mature area of study in urban areas that have a large impervious area fraction
and where problems such as flooding and sediment erosion may occur if stormwater is not
adequately managed (Mays, 2001). Urban areas are also a source of a variety of pollutants,
which may be transported through stormwater, typically through the erosion or washoff of
particulates. Early documentation of the water pollution aspects of street surface contaminants is
provided in Sartor et al., 1974. Many pollutants adhere to particles and may therefore be
transported along with the particulates. Stormwater runoff from urban areas is often associated
with pathogenic and organic substances that are of public health concern.
Over the past three decades, a variety of public-domain and proprietary modeling tools have
been developed for tracking stormwater hydrology, hydraulics, and quality. Hydrology-based
models represent rainfall-runoff processes and routing through channels and reservoirs, focusing
primarily on calculating flow volumes using formulas that preserve the conservation of mass.
However, hydraulic models involve the conservation of mass and momentum and represent fluid
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transport processes in more detail, including characterization of water surface profiles, flow
rates, and flow velocities on surfaces and in pipelines and channels. The use of a hydrology vs
hydraulic model is very situation-dependent. For example, during an emergency response, if the
primary question is "How much water is the concern and in what structure is the water after a
rain event?" then a hydrology-based model would suffice. Conversely, if a responder wanted to
know if material could be scoured out of a contaminated pipe, it would help to predict flow
velocity, and a hydraulic model would be necessary. Water quality models characterize transport
of dissolved or particulate pollutants and are usually coupled with hydrology/hydraulic models.
To model the quantity of stormwater, several hydrological processes need to be characterized.
Precipitation falling on land surfaces is subject to evaporation and initial loss due to interception
by vegetation. Excess rainfall is available for infiltration, overland flow, and depression storage.
Infiltrated water may flow through the upper layer of the soil where some of this water may
become interflow between adjacent soil layers or flow more deeply into the soil, reaching the
groundwater. Stormwater flow is routed through land surfaces, stream reaches, and through
engineered stormwater infrastructure (e.g., drainage pipes, channels, catch-basins, and pump-
stations, etc.). Representation of stormwater flow is an important element of stormwater
modeling, and the representation can be analyzed at different levels of detail, from mechanistic
models of physical processes to more general statistical or empirical relationships (Westphal,
2001). For modeling stormwater hydraulics, the shallow water dynamic wave equations (i.e., the
Saint-Venant equations) can be solved numerically to simulate unsteady one-dimensional flows
in open and natural channels or in pressurized closed conduits (Zoppou, 2001). Approximations
to the shallow wave equations are also used, including the kinematic wave model and diffusion
wave models in one or two dimensions (Zoppou, 2001; Mays, 2001).
The ultimate goal of the modeling tools compiled in this report is to characterize the spatial
extent of contamination following transport through stormwater and to inform cleanup activities
in an emergency setting, including over a longer duration, as the extent of contamination is better
understood. In this respect, the potential application is different from typical stormwater quality
tools that are focused on more-or-less ubiquitous continuous contaminant sources, with a focus
of estimating and controlling loading rates to downstream waters.
3.0 Model Review Process
3.1 Initial Screening
An initial list of available stormwater models that potentially simulate both stormwater flow and
fate and transport of pollutants in the watershed was obtained from a list compiled by the
Minnesota Pollution Control Agency (MPCA, 2017). This list was supplemented with additional
reviews of stormwater models in the peer-reviewed literature and standard text references
(Zoppou, 2001; Elliott and Trowsdale, 2007; Mays, 2001). The combined set of models screened
in this work is more extensive than in any prior evaluation and is also focused on an assessment
specific to the goals of modeling biological and radiological contaminants during emergency
response and remediation. The models used in the initial screen are listed in Appendix A in
alphabetical order. The models were first characterized based on the following criteria (denoted
as "x" in Appendix A, when the characteristic applied):
• Hydrologic Model,
• Hydraulic Model,
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• Combined Hydrology and Hydraulic Model,
• Pollutant Transport,
• Water Quality Model,
• Receiving Water Model,
• Simulates Best Management Practices (BMPs),
• Proprietary, and
• Developer.
Because simulation of pollutant transport on landscape surfaces is important in this study,
hydraulics-only models and those models that only simulate receiving waters were excluded
from detailed review after the initial screening. While there may be potential for coupling a
hydraulics model with a water quality model for emergency response applications, it was
assumed this would require a substantial coding effort. The initial assessment resulted in a total
of 26 models for detailed review. In Appendix A, each of the screened models is identified, and
the reason for exclusion of each model from the detailed review is briefly described. These
models are unlikely to provide information on the transport of pollutants on land surfaces
without substantial further development. All other models were characterized in greater detail as
described below.
3.2 Detailed Review and Quality Assurance
For the detailed model review, a variety of sources of information were consulted, including
peer-reviewed and gray literature. The information used for each model review was derived from
several sources: 1) description, documentation, manuals, and factsheets listed on the model's
official website; 2) literature searches based on the model's name; and 3) a review of case studies
of model applications from real study sites obtained from internet searches. This work also
included outreach to model developers or the company selling the model, contacts from other
specialist users, and our own experience in using some of these modeling tools. Given the broad
range of models considered, direct testing of each model was beyond the scope of the present
review. Also, some models differed in the extent of information available in the public domain
(e.g., journal articles and user manuals available without purchase of the software).
A set of evaluation criteria was used to systematically characterize the models in the survey and
is listed in Table 1. These criteria were developed by the project team based on experience
working in either the stormwater or emergency response sector, or both. Model prevalence refers
to the extent to which the model has been used in various applications. Several approaches were
used to evaluate model prevalence, including: 1) the number of applications of the model in
literature case studies, and 2) the number of model users. Information regarding extent of model
use can be derived either from the model's website or from the literature. When the model was
estimated to have over a hundred applications or users, we characterized the model prevalence as
high. When more than 10 applications were found, we characterized the model as somewhat
prevalent (moderate). If the number of the model applications was not available from the model
website, we did an online search for recent individual applications. If few applications were
estimated to have been reported and could not be generally quantified, the model prevalence was
characterized as low. Model prevalence in peer reviewed literature and real-world applications
was also included in the summaries to provide an indication as to the industry's acceptance of the
model being a quality tool.
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The Ease of use for public utilities was classified as easy, moderate or advanced. The ease of
use was defined according to the complexity of the model and based on model case studies.
When the model is a spreadsheet-type model and requires minimal inputs (e.g., simple calculator
type of model), the model is characterized as easy to use. If the model is more complicated with
representation of watershed processes and a greater number of inputs, the model is characterized
as moderate. When the model has a more complicated representation of hydrology and
hydraulics processes requiring multiple input layers and adjustable parameters (e.g.,
Hydrological Simulation Program-Fortran [HSPF]) or has sewer/storm water network
calculations (e.g., CivilStorm), the model is considered advanced. The ease of model use was
also verified by reviewing case studies of model applications for each model.
The Representation of uncertainty describes in narrative form how the model handles
uncertainty in predictions, either due to uncertainty in the input, model representation of certain
parameters, or in the output. Most of the stormwater models reviewed here are deterministic,
with model inputs used to predict a single set of outputs (Lind, 2015). For these deterministic
models, the uncertainty can be derived externally by users through uncertainty analysis of the
inputs or through sensitivity analysis. The uncertainty specified in inputs by users can then be
propagated through the model by running different model scenarios through the range of the
inputs. Some models (e.g., PCSWMM) offer a tool in the model for the user to specify an input
range for addressing the uncertainty in input variables, while other models may offer options to
specify stochastic distribution of rainfall input (e.g., 100-yr rainfall, 5-yr rainfall; HydroCAD,
2011). For models that possess some inherent randomness, stochastic representations of the
model inputs and its representation of uncertainty are built directly into the model (Lind, 2015).
For example, the Monte Carlo method was incorporated into the Stochastic Empirical Loading
and Dilution Model (SELDM) model to produce random combinations of input variable values.
The Ease of obtaining information and availability of technical support criterion for each
model was evaluated using information provided on the model website or through a literature
search and reported in narrative form. Another criterion for evaluation is Data assembly
requirements during and after emergency response. Selected stormwater models are intended to
be used during or soon after an emergency event in any arbitrary location in the country. Setting
up the models beforehand is impractical, except for a few key locations. How quickly these
models can be assembled during an emergency response is therefore an important evaluation
criterion. Some models have built-in functions or data to simulate the required inputs (e.g.,
rainfall) or to extract data from the internet. These requirements were ranked as low. Some
models are geographic information system (GlS)-based and can derive watershed data (e.g.,
slope, watershed area) from a digital elevation model (DEM), which can be obtained from
national-scale databases. These models have fewer data requirements, may be assembled
relatively quickly, and are rated as moderate with respect to data assembly requirements. Other
models have more site-specific data requirements such as the details of a stormwater network,
junctions, BMPs or low impact developments (LIDs), which may not be readily available.
Therefore, the rating for data assembly requirements for these models is considered high. In
addition to the criteria previously described, the detailed review also looked at stormwater
LID/BMPs as well as data and software compatibility, whether the model is event-based or
continuous, lumped (i.e., variables in a land area are represented as aerial weighted averages) or
distributed (i.e., variables of each homogenous land area are represented individually), empirical
or physical, where the model was used, and other general features. Table 1 provides further
explanation for the criteria used in the model survey. Model runtime was not included in the
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criteria due to its dependence on available computing power and modeling domain. Post-
processing of outputs was also not included because the extent of post-processing can vary
greatly depending on the parameter.
Table 1: Explanation of stormwater model survey evaluation criteria
Criterion
Explanation
Developer
Name of company/agency/individual who
developed the model.
Version
The version number of the model at the
time of this review
Hardware computing requirements
Specific computational requirements, if
specified.
Code language
Language in which the model was coded.
Original application (e.g. urban,
rural)
Focus of the original model, type of
landscape and conditions modeled in the
literature. In general, the model was
considered urban or suburban if the
original application was for stormwater
utilities with a high population density
and piped infrastructure and rural if the
applications were more agriculturally
based.
Public/proprietary and cost
Whether model and source code are
public and modifiable, or if proprietary.
Where available, specific licensing costs
were reported.
Physically or empirically based
Whether the underlying formulation of the
model solves mechanistic equations of
flow and transport or is based on an
empirical formulation. Both types of
model are considered.
Mathematical method for flow
routing and water quality
Mechanistic or empirical approaches used
for flow routing and contaminant
transport for physically based models.
Input data requirements
Typical input data needs, and difficulty of
preparing these data sets from publicly-
available information.
Data assembly requirements
during and after emergency
response
As above, but specifically considering the
potential of rapidly setting up a model run
to respond to an emergency
Outputs
Nature and format of outputs
Representation of uncertainty
How is uncertainty analysis integrated
into the modeling framework?
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Prevalence
How common is the model? Are there
many known applications (not just peer-
reviewed publications)?
Ease of use for public utilities
What are the barriers to the widespread
use of the model in terms of training or
specialized supporting hardware and
software?
Ease of obtaining information and
availability of technical support
Is the model actively supported with an
engaged user group or commercial help
desk?
Source code availability
Is the source code available for
modification if needed?
Status of model development
Is the model developed and available for
immediate use? This category may
include models that continue to be
updated.
4.0 Results of Model Review
Summaries for the models that were reviewed in detail are presented in Appendix B, with text
descriptions associated with the criteria listed in Table 1. In summary, based on the review here,
models were classified into four categories: the SWMM family (sewer and stormwater
modeling), detailed sewer pipe-only models, watershed models, and simple empirical models
(support tools). These categories are briefly described below (in no special order) and graphically
in Mikelonis et al., 2018.
4.1 SWMM Family of Models
One grouping that emerged during the detailed review was the SWMM family of models (EPA
SWMM, PCSWMM, InfoSWMM, and XPSWMM), which offer comprehensive capabilities to
simulate stormwater hydrology, hydraulics, pollutants, and LID/BMPs/control devices. The
individual models differ in the quality of the user interface and GIS computer-aided design
(CAD) platforms and specialized tools. The free version of EPA SWMM supports some
schematic representation of the drainage areas and storm-drain network but does not have
algorithms to establish a 2D flow mesh. Commercial versions that run the baseline EPA SWMM
code and add additional functionality are described below:
• PCSWMM expands EPA SWMM5 with ID or 2D urban flood modeling capabilities.
PCSWMM is a stand-alone application with built-in GIS functionalities, including tools that
can determine drainage areas from a digital elevation model and stream network.
• InfoSWMM is an ArcMap extension of the EPA SWMM5 model. The model is provided as
an extension to the ESRI ArcGIS platform. Therefore, the ESRI ArcGIS software is required
for setting up the model. InfoSWMM provides ArcGIS integration and capabilities for
wastewater and stormwater modeling and a greater number of hydrology representation
methods.
• XPSWMM is another interface for SWMM5 (and parts of SWMM4) for modeling
stormwater, sewers and floodplains. XPSWMM also simulates both ID and 2D overland
flow. The model allows GIS and CAD integration and allows for easy setup of a site with
external data.
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• SUSTAIN (Shoemaker et al., 2011) is a stormwater model interface that uses the SWMM
hydrology engine. In addition to predicting stormwater runoff, SUSTAIN is a decision
support system for optimally selecting locations of stormwater BMPs and their costs. Since
the framework for SUSTAIN is from a different lens than emergency response it would need
to be reworked before being an applicable tool for recovery.
4.2 Sewershed and Sewer Network Models
The second category of models includes detailed sewer models that simulate storm sewer
networks and associated catchments. These models include: InfoWorks Integrated Catchment
Model (ICM), MikeUrban and CivilStorm. These models offer capabilities to simulate sewer
network hydraulics, as well as ID or 2D surface overland flow. These models may use portions
of the SWMM code, but also contain their own proprietary engines for flow routing and pollutant
fate and transport. Typically, they are used in urban flood management studies. They cover very
comprehensive modeling features but are expensive.
4.3 Watershed Models
The third category of models includes watershed models or pollutant transport models that
simulate stormwater flow and pollutant loads. These models range from simple lumped models
that use the same parameter values for the entire watershed, to more comprehensive spatially
distributed models such as the Soil & Water Assessment Tool (SWAT), HSPF and the Gridded
Surface Subsurface Hydrologic Analysis (GSSHA) model. These models can simulate transport
and reaction of pollutants across the watershed and effects of stormwater control facilities and
best management practices, although several lack capabilities to simulate detailed stormwater
sewer networks. These models have been used extensively in studies to characterize pollutant
loads to receiving waters in watersheds with mixed land use, as part of total maximum daily load
(TMDL) analyses.
The fourth category of models includes the simple spreadsheet-type calculator tools for
estimating stormwater flow and pollutant load and sometimes effects of stormwater BMPs, such
as BMP System Effectiveness and Life-Cycle Evaluation of Costs Tool (SELECT), the
Stochastic Empirical Loading and Dilution Model (SELDM), the Minimal Impact Design
Standards (MIDS) calculator, and the Spreadsheet Tool for Estimating Pollutant Loads (STEPL).
These models provide simple calculations for stormwater flow and pollutant loads, can be
applied relatively easily, and may have applications for stormwater modeling where rapid results
with minimal data are essential.
5.0 Discussion
The model review shows that a vast number of choices exist for further development, with the
following observations: (1) most commercial modeling frameworks are not open, limiting their
adaptability for new types of process representation if needed; (2) some of the commonly used
urban modeling packages are relatively expensive, with licensing costs of several thousand
dollars per year; (3) uncertainty analysis is rarely a feature of most models, and typically such
analysis is done by re-running the model with different parameters; and (4) model complexity is
tied to input data complexity and user expertise.
Providing decision makers with an estimation of transport of radiological contaminants and
biological agents during emergency response and recovery, are not directly addressed through
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currently available off-the-shelf models. No one model is readily usable for the types of
applications needed, including the need for modeling small-scale prototypes and rapid
application in urban areas with complex catchments. However, based on the model review
presented here, and the experience and evaluation of the reviewers, the SWMM class of models
is appropriate for future development as part of an effort to provide information on biological
and radiological contaminants fate and transport during emergency response and recovery
because of the availability of the source code, the overall robustness and prevalence of the
SWMM engine, and basic capability of the SWMM model to handle the underlying flow and
contaminant transport processes.
This review clearly shows that complex models have substantial data requirements that may not
be readily available in an emergency. Rather than developing site-specific models in such a
situation, it may be helpful to have a set of archetype models, with typical urban settings and
driven by ranges of parameters (rainfall, slope, washoff, etc.), pre-run for use under such
conditions. Ultimately, it is important to recognize that the choice of modeling software during
an emergency may also be heavily influenced by the preexisting software choice of the affected
municipality. Future development is recommended not only to expand the SWMM family
functionality for emergency response, but also to improve the conversion and transfer between
different software frameworks. Model applications originally developed in a specific SWMM
family commercial framework can be challenging to transfer from one software framework to
another as there are usually subtle differences between the model representation of data that
prevent a straightforward transformation from one package to another, especially for complex
city-scale models. It is important that tools created during future research projects be as flexible
as possible in being able to interact with multiple software platforms.
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6.0 References
Barr, 2011. Assessment of MIDS performance goal alternatives: runoff volume, runoff rates, and
pollutant removal efficiencies. Report prepared for Minnesota Pollution Control Agency
(MPCA). https://www.pca.state.mn.us/sites/default/files/p-gen3-12w.pdf. (Last accessed August
9, 2018).
Barr, 2014. Minimal Impact Design Standards for enhancing stormwater management in
Minnesota. Minnesota MIDS GUI calculator user manual. Version 2: June 2014.
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Bentley Systems, 2014. CivilStorm: Comprehensive Stormwater Modeling and Analysis.
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Bonnema, M., G. Perry, N. Warner, C. Young, 2014. North St. Paul Resilient Communities
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30, 2018).
Downer, C.W., and F.L. Ogden, 2006. Gridded surface subsurface hydrologic analysis (GSSHA)
User's Manual. Version 1.43 for watershed modeling system 6.1.
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31, 2018).
Elliott, A. H. and S. A. Trowsdale, 2007. A review of models for low impact urban stormwater
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Guide. http://www.mapshed.psu.edu/Downloads/MapShedMan.iial.pdf (Last accessed August 31,
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Robillard, R.L. Day, 2002. A comprehensive GIS-based modelling approach for predicting
nutrient loads in watersheds. Journal of Spatial Hydrology. 2(2) (www.spatiahydrology.com).
Granato, G.E., 2013. Stochastic empirical loading and dilution model (SELDM) version 1.0.0:
USGS techniques and methods. Book 4, chap. C3, 112P., CD- ROM. (also available at
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-------
Granato, G.E., and S.C. Jones, 2013. The stochastic empirical loading and dilution model
(SELDM) for stormwater-quality risk analyses, (main manual as 4.45)
https://pubs.uses.gov/tm/04/cQ3/ (Last accessed August 31, 2018).
Haith, D.A., R. Mandel, R.S. Wu, 1992. Generalized Watershed Loading Functions. Version 2.0.
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Herr, J., Weintraub, L. H. Z., and Chen, C. W. (2001). User's Guide to WARMF:
Documentation of Graphical User Interface.
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https://www.hvdrocad.net/pdf/Hv' Z0Own.ers%20Manual.pdf
(Last accessed August 31, 2018).
James, W., L.E. Rossman, and W.R.C. James, 2013. Computational Hydraulics Int. (CHI).
User's Guide to SWMM5. 13thEdition.
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2018).
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PCSWMM and EPA SWMM5. https://trieca.com/app/uploads/20f6/Q7/LID-Modeling-Mar-28-
2012.pdf (Last accessed August 31, 2018).
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1D-2D modeling, http://dc.engconfintl.org/watershe (Last accessed August 31, 2012).
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watershed in the northeastern US: a comparison of HSPF and SMR. Journal of Hydrology,
284(1-4), 57-76.
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portal.Org/smash/get/diva2:803803/FULLTEXT01.pdf (Last accessed August 31, 2018).
Mays, L.W., Editor. 2001. Stormwater Collection Systems Design Handbook. ISBN-13: 978-
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framework (SUSTAIN) and field applications for placement of BMPs in urban watersheds.
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-------
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16(3): 195-231.
-------
Appendix A - Models in Initial Screening 1
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
l
BASINS
Watershed modeling
system
X
X
X
X
X
EPA
Y
2
BasinSiml.O
Watershed modeling
package based on
Generalized Watershed
Loading Function model
"(GWLF)
X
X
X
Virginia Inst,
of Marine
Sciences
Y
3
Bathtub
Empirical model of
reservoir eutrophication
X
United States
Army Corps
of Engineers
(USACE)
N
Receiving water
model only
4
CE-QUAL-W2
Water quality and
hydrodynamic model in 2D
(longitudinal-vertical) for
rivers, estuaries, lakes,
reservoirs
X
X
USACE and
Portland State
University
N
Receiving water
model only
5
CivilStorm
Comprehensive stormwater
modeling and analysis
software.
X
X
X
X
X
Bentley
Y
6
Culvertmaster
Flydraulic analysis for
culvert design
X
X
Haestad
Methods,
Bentley
Systems, Inc.
N
Culvert design
only
7
EPD-RIV1
One Dimensional Riverine
Flydrodynamic and Water
Quality Model
X
X
Georgia
Environmental
Protection
Division and
EPA
N
Receiving water
model only
8
FHWA Hydraulic
Toolbox
Flydraulics model for
transportation structures
X
Federal
Highway
Authority
(FHWA)
N
Hydraulic
model only
9
Flowmaster
Flydraulic analysis program
for design and analysis of
open channels, pressure
pipes, inlets, gutters, weirs,
and orifices
X
X
Haestad
Methods,
Bentley
Systems, Inc.
N
Hydraulic
model only
Note: "x" means the model characteristic applies
-------
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
10
GWLF
GWLF is a watershed
loading model developed to
assess nonpoint source flow
and sediment and nutrient
loading from urban and
rural watersheds
X
X
X
Cornell
LTniversity
Y
11
Green Values
National
Stomi water
Management
Calculator
A tool for quickly
comparing the
performance, costs, and
benefits of Green
Infrastructure or LID, to
conventional stormwater
practices.
X
Center for
Neighborhood
Technology
N
BMP only
12
GSSHA
Gridded surface subsurface
hydrologic analysis
X
X
X
X
USACE
Y
13
HEC-HMS
Hydrologic rainfall-runoff
model. Computes
hydrographs for a network
of watersheds
X
X
X
USACE
Y
14
HEC-RAS
River hydraulic model
X
X
X
USACE
N
River model
only
15
HSPF
A watershed scale model
for estimating in-stream
concentrations resulting
from loadings from point
and non-point sources
X
X
X
EPA
Y
16
HY8
Culvert hydraulic
computations and design
software
X
FHWA
N
Hydraulic
model only
17
HYDRO AS2D
2-D finite element flow
modeling package
X
X
X
X
Aquaveo
N
River model
only
18
HydroCAD
Civil Engineering design
tool. Provides calculation
for runoff hydrology,
hydrograph, routing,
hydraulics, culvert
calculations, land use and
loading
X
X
X
X
HydroCAD
Software
Solutions LLC
Y
-------
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
19
ICPR
Integrated 2D surface water
and groundwater flow
model.
X
X
X
Streamline
Technologies
N
No pollutant
modeling
20
InfoSWMM
Commercial
implementation of
SWMM5
X
X
X
X
X
Innovyze
Y
21
InfoWorks ICM
Integrated modeling
platform to incorporate
both urban and river
catchments. InfoWorks
ICM enables the hydraulics
and hydrology of natural
and man-made
environments
X
X
X
X
X
Innovyze
Y
22
i-Tree Hydro
Stand-alone application
designed to simulate the
effects of changes in tree
and impervious cover
characteristics within a
defined watershed on
stream flow and water
quality
X
X
X
SUNY-ESF
N
No pollutant
transport or
hydraulics
23
i-Tree Streets
Analysis tool for urban
forest managers that uses
tree inventory data to
quantify the dollar value of
annual environmental and
aesthetic benefits
X
X
X
SUNY-ESF
N
No pollutant
transport or
hydraulics
24
LSPC
Like HSPF
X
X
X
Tetra Tech,
available from
EPA
Y
25
MapShed
A customized GIS interface
that is used to create input
data for an enhanced
version of the GWLF
watershed model
X
X
X
X
Penn State
Y
26
Metropolitan
Council
Stormwater Reuse
Guide
Excel-based stormwater
comparison tool
X
Metropolitan
Council, Twin
Cities Region,
MN
N
BMP only
27
MIDS calculator
Stomi water quality tool to
predict annual pollutant
removal and runoff volume
of various LID BMPs
X
X
X
Minnesota
Pollution
Control
Agency
Y
-------
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
28
MIDUSS
Model for stormwater
management, design and
analysis. Hydrology
features: storms, rainfall
abstraction, overland flow
routing. Design features:
pipes, channels, detention
pond, exfiltration trench,
culvert
X
X
X
Scientific
Software
Group
N
No pollutant
modeling
29
MIKE 11
A river model and general-
purpose river modeling
toolbox
X
X
X
DHI
N
River model
only
30
MikeUrban
Modeling for urban
catchments
X
X
X
X
X
DHI
Y
31
MODRET
Calculates unsaturated and
saturated infiltration losses
from stormwater
retention/detention ponds
X
X
Scientific
Software
Group
N
No pollutant
modeling
32
National
Stomi water
Calculator
Tool for computing small
site hydrology for any
location within US and for
identifying BMPs for
managing stormwater
X
USEPA
N
Runoff only
33
P8
Physically-based
stomi water quality model
developed to predict the
generation and transport of
stomi water runoff
pollutants in urban
watersheds
X
X
X
X
W.W. Walker
and J.D.
Walker
Y
34
PCSWMM
Commercial
implementation of
SWMM5
X
X
X
X
X
CHI
Y
35
PLOAD
A pollutant loading model
X
X
X
CH2M HILL
for EPA
N
Simplified
model lacking
detailed
accounting of
stomi water
processes
36
PONDNET
An empirical model
developed to evaluate flow
and phosphorus routing in
pond networks
X
X
X
William W.
Walker
N
Receiving water
model only
-------
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
37
PondPack
Program for modeling and
design of the hydrology and
hydraulics of storm water
runoff and pond networks,
for urban and rural
watersheds
X
X
X
Bentley
N
No pollutant
modeling
38
QHM
A continuous watershed
quantity and quality
simulation model intended
for watershed management
and stormwater design.
X
X
X
X
X
Scientific
Software
Group
N
Older software
(for Windows
XP and older).
Developer
indicated they
had no plans for
updating.
39
QUAL2E
A water quality and
eutrophication model
X
X
EPA
N
Receiving water
model only
40
Rainwater
Harvesting Model
Simplified model for
stomiwater volume
estimation
X
X
North
Carolina State
University
N
Runoff/BMP
only
41
Rational method
Simple calculation of peak
flow based on drainage
area, rainfall intensity, and
non-dimensional runoff
coefficient
X
In common
use for more
than a century
N
Runoff only
42
RECARGA
This model is used for
evaluating the performance
of bioretention facilities,
rain gardens, and
infiltration basins.
X
Wisconsin
Department of
Natural
Resources
(DNR)
N
BMP only
43
SELDM
Planning-level estimates of
event mean concentrations,
flows, and loads in
stormwater from a site and
an upstream basin interest
X
X
X
United States
Geological
Survey
(USGS)/
EHWA
Y
Provides only
simplified
estimates of
loads and Event
Mean
Concentrations
(EMCs).
44
SELECT
Planning level tool that
uses long-term records to
drive the model
X
X
X
X
WERF
Y
45
SHSAM
Simulates runoff and
removal of suspended
sediments from stormwater
X
X
X
X
BARR
Engineering
Y
-------
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
46
STEPL
Nutrient and sediment loads
from different rural land
uses and BMPs on a
watershed scale. Simulates
watershed surface runoff
nutrient loads, BOD5,
sediment delivery
X
X
EPA
Y
47
StormNET
StormNet is software for
stomiwater modeling.
X
X
X
X
BOSS
International
Y
48
Stormwater Reuse
Calculator
Simplified model for
stomi water volume and
management
X
Minnehaha
Creek
Watershed
District
N
BMP only
49
SUSTAIN
Model for stomi water flow
and BMPs on a watershed
scale, based on SWMM
X
X
X
X
EPA
N
Basic
stomi water
processes are
the same as
SWMM (same
engine) and
covered in the
review of other
models
50
SWAT
A physical based,
watershed scale model that
predicts the impacts of land
management practices on
water, sediment and
agricultural chemical yields
X
X
X
United States
Department of
Agriculture
(USDA) with
Texas A&M
University
Y
51
SWMM5
General stomi water model;
this code underlies several
commercial models
X
X
X
X
EPA
Y
52
TR-20
Single event watershed
scale runoff and routing
model
X
Natural
Resources
Conservation
Service
(NRCS)
N
Runoff only
53
TR-55
Simplified procedure to
calculate stomi water runoff
volume, peak rate of
discharge, hydrographs and
storage volumes in small
urban watersheds
X
NRCS
N
Runoff only
54
Virginia Runoff
Reduction Method
Excel spreadsheets for
regulatory compliance
X
Virginia
Department of
Environmental
Quality
N
Runoff only
-------
Item
#
Model
Description
Model Characteristic
Developer
Included in Detailed
Review?
Reason(s) for
exclusion from
detailed review
Hydrologic Model
Hydraulics Model
Combined Hydrology
and Hydraulic Model
Pollutant Transport
Water Quality Model
Receiving Water Model
Simulates BMP?
Proprietary
55
WARMF
Watershed model that
simulates runoff, pollutant
transport, and water quality
X
X
X
Systech
Y
56
WASP
Evaluates fate and transport
of contaminants in surface
waters
X
X
EPA
N
Receiving water
model only
57
WinSLAMM
Stonnwater quality model
for evaluation of nonpoint
pollution in urban areas
X
X
X
X
X
PV and
Associates
Y
58
WiLMS
The Wisconsin Lake
Modeling Suite (WiLMS)
model is a lake water
quality-planning tool. The
model includes a front-end,
phosphorus prediction,
internal loading and trophic
response
X
X
Wisconsin
Department of
Natural
Resources
N
Lake water
quality model
only
59
WMM
Estimates annual/seasonal
nonpoint pollutant loads
from direct runoff on
watersheds and sub-basins.
X
X
X
CDM
N
Limited
temporal detail
in stormwater
modeling
60
WSPRO
Hydraulic model for water
surface profiles
X
X
uses
N
River model
only
61
WWHM
Tool developed to size
stormwater control facilities
to mitigate the effects of
increased runoff from
proposed land use changes.
X
X
Washington
State
Department of
Ecology
N
No pollutant
modeling
62
XPSWMM
Commercial
implementation of
SWMM5
X
X
X
X
X
XP Solutions
(owned by
Innovyze)
Y
-------
Appendix B - Model Summaries
The table below provides example references for those unfamiliar with the hydrologic equations
and methods referenced in the model summaries. (The links were last referenced on August 28,
2018.)
Named Equations
Reference
Bagnold's Equation
Bagnold. 1977
(Water Resources Research)
Chezy-Manning Equation
Water Resources Engineering
(Larry Mays, 2nd Edition, Eqn 5.1.2.1)
Manning's Equation
Water Resources Engineering
(Larry Mays, 2nd Edition, Eqn 5.1.2.2)
Saint-Venant Equations
Desktop Review of 2D Hydraulic Modeling Packages
(Defra Science Report SC080035, Section 2.1)
Universal Soil Loss Equation
(USLE)
Predicting Rainfall Erosion Losses
(USDA Agriculture Handbook Number 537)
MUSLE (modified USLE)
Merritt ei. a!., 2008
(Environmental Modeling & Software)
Methods
Reference
Ackers-White method
Maver et. al.„ 2009
(River, Coastal andEstuarine Morphodynamics, Santa Fe-
Argentyna, A. Balkena Book)
Clark method
Water Resources Engineering
(Larry Mays, 2nd Edition, Section 8.4.2)
Darcy's Law
Water Resources Engineering
(Larry Mays, 2nd Edition, Section 4.1)
Engelund-Freds0e method
Engelund and Freds0e„ 1976
(Hydrology Research)
Green-Ampt method
Water Resources Engineering
(Larry Mays, 2nd Edition, Section 7.4.2)
Hargreaves method
Hargreaves. 1985
(Applied Engineering in Agriculture)
Horton's method
Water Resources Engineering
(Larry Mays, 2nd Edition, Section 7.4.3)
-------
Modified Horton method
Akan. 1992
(Journal of Irrigation and Drainage Engineering)
ModClark, Initial & constant
loss infiltration method, linear
reservoir routing method,
nonlinear Boussinesq method,
lag routing method, and Puis
routing method
HEC-HMS Technical Reference Manual
(CPD-74B, March, 2000)
Muskingum-Cunge method
Technical Paper No, 135
(USACE Hydrologic Engineering Center)
Muskingum routing method
Nash, 1959
(Journal of Geophysical Research)
NRCS-TR55 method
13 n Hydrology for Small Watersheds TR-55
Santa Barbara Urban
Hydrograph method
Stubchaer, 1975
(National Symposium on Urban Hydrology and Sediment Control)
SCS curve number method
U n Hydrology for Small Watersheds TR-55
(Chapter 2)
SCS unit hydrograph method
USD A Part 630 Hydrology National Engineering Handbook
(Chapter 16)
Penman-Monteith method
Sumner and Jacobs. 2005
(Journal of Hydrology)
Priestly-Taylor
Sumner and Jacobs, 2005
(Journal of Hydrology)
RDII (Rainfall Dependent
Infiltration and Inflow) method
Review of Sewer Design Criteria a ction Methods
(EPA/600/R-08/010)
Snyder method
Water Resources Engineering
(Larry Mays, 2nd Edition, Section 8.4.1)
van Rijn method
van Rii 1
(Journal of Hydraulic Engineering)
-------
B.1 BASINS (Better Assessment Science Integrating point and Non-point
Sources)
Developer: Office of Water, EPA
Description: BASINS, a multi-model system that supports watershed management and TMDL
development, provides an integrated platform to conduct analysis using different environmental data,
analysis tools, and watershed and water quality models. BASINS uses a GIS for organizing spatial
information used in the analysis. It provides access to national datasets of DEMs, land use and soils that
can be used in the analysis. BASINS also incorporates multiple watershed and water quality modeling
tools into the system, including: Hydrologic Simulation Program - Fortran (HSPF), the Soil and Water
Assessment Tool (SWAT), the EPA Storm Water Management Model (SWMM), Generalized Watershed
Loading Function model extension (GWLF-E) Mapshed, and the Pollutant Loading Estimator (PLOAD),
and water quality models including: AQUATOX and Water Quality Analysis Simulation Program
(WASP). Some of these models are described elsewhere in Appendix B.
Versions: v4.1 (complete), v4.2 test version (under development)
Features: BASINS provides an automatic data download tool, such as DEM, stream network, land use,
meteorology, and water quality data that can automatically download data needed for watershed
modeling. BASINS provides access and tools to set up watershed and water quality models and also
provides tools for watershed characterization, manual and automatic watershed delineation, WDMUtil for
time series data generation, GenScn utility for post processing, and climate assessment tool (CAT) for
climate change analysis.
Original Application: Urban
Mathematical method for flow routing and water quality: Depends on the watershed or water quality
model selected for the application. See associated sections of this report for relevant models.
Input Data Requirements: Only the site location is necessary since data can be downloaded
automatically. User specified site-specific data can also be incorporated into the model.
Data assembly requirements during and after emergency response: Moderate
Outputs: Spatial information of the watershed studied, outputs from models such as flow and water
quality data. See associated one pagers for relevant models.
Representation of Uncertainty: Depends on the watershed or water quality model selected for the
application
Hardware computing requirements: Minimum requirements: 1 GHz processor, 2.0 GB available hard
disk, 512 MB of RAM, 16-bit color resolution monitor, internet, Windows XP, Vista, or Windows 7 and
8 operating systems. BASINS 4.1 is also 64-bit compatible.
Code language: C#
Public/Proprietary and Cost: Public, free
Prevalence: High.
Ease of use for public utilities: Moderate
Ease of obtaining information and availability of technical support: Support is available through
email from EPA's BASINS Support Team. A user group mailing list is also available to answer technical
questions.
Source code availability: Source code for BASINS 4 is available in the MapWindow code repository.
Source codes for individual models are also available for HSPF, SWAT and SWMM.
Installation requirements/software: MapWindow
Source/Link: https://www.epa.gov/exposure-assessment-models/basins (Last accessed August 13, 2018.)
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B.2 BasinSim 1.0
Developer: Ting Dai, Richard L. Wetzel, T.R.L. Christiansen, and E.A. Lewis at the Virginia Institute of
Marine Science (VIMS)
Description: BasinSiml.O is a desktop simulation system that predicts sediment and nutrient loads from
small to mid-sized watersheds. The simulation system is based on the Generalized Watershed Loading
Functions (GWLF) (Haith el. al., 1992). BasinSim 1.0 integrates the GWLF model and extensive
databases, including land uses, population, soils, flow, water quality, climate, and point nutrient sources
and was designed to enable resource managers to visualize and manipulate data and conduct model
simulations.
Versions: vl.O
Features: BasinSim 1.0 provides a user interface for the watershed model GWLF and provides extensive
datasets for modeling. It can be used to create and modify input data, display data and results in maps and
graphs, compare simulation scenarios and options for data manipulation, and has a capability to calculate
sediment, nutrient, and pollutant loads.
Original Application: Urban
Mathematical method for flow routing and water quality: see GWLF summary.
Input Data Requirements: see GWLF summary.
Data assembly requirements during and after emergency response: Moderate
Outputs: Flow and water quality
Representation of Uncertainty: None
Hardware computing requirements: BasinSim 1.0 requires an IBM PC-compatible computer
running Windows95 or above and about 20 MB of hard-drive space.
Code language: Visual Basic 6.0
Public/proprietary and Cost: Public, free
Prevalence: Low
Ease of use for public utilities: Moderate
Ease of obtaining information and availability of technical support: Not available
Source code availability: Not available
Installation requirements/software: None
Source/Link: http://web.vims.edu/bio/models/bsabout.html (Last accessed August 13, 2018)
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B.3 CivilStorm
Developer: Bentley
Description. CivilStorm is a dynamic hydrologic and hydraulic model developed for complex stormwater
systems (Bentley Systems, 2014). The model, with built-in hydraulic and hydrology tools and wet-
weather calibration methods, has been used in stormwater master plan development, water quality studies,
and to design, analyze, and operate stormwater systems.
Versions: v8
Features: Comprehensive analysis of all aspects of stormwater systems: rainfall, runoff, inlet capture and
bypass, gravity and pressure piping, ponds, outlet structures, open channels, and culverts. Used for design
of stormwater systems, simulation of hydraulics using multiple solvers, and simulation of water quality.
CivilStorm can work as a stand-alone application or can be run from within MicroStation or AutoCAD.
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff/Infiltration: SWMM and
hydrograph methods (RTK, Soil Conservation Service (SCS) curve number method, modified Rational);
Flow Routing: SWMM dynamic and kinematic solver or gradually varied flow solver (peak flow
calculation uses the rational method); Water Quality: see SWMM summary.
Input Data Requirements: See SWMM summary.
Data assembly requirements during and after emergency response: Low
Output: Flow, depth, and water quality injunctions and outfalls that is in a format compatible with
Computer Aided Design (CAD)/GIS. Micro Station V8i Select series 3, AutoCAD 2014, 2015 (32-bit/64-
bit), ArcGIS 10.2, databases, ProjectWise v8i.
Representation of Uncertainty: No specific uncertainty tool.
Hardware computing requirements: Windows 8.1 (32-/64-bit)
Code language: a mix of C++, .NET, C#, SQL, and Fortran
Public/proprietary and Cost: $1,481 for 10 links (conduits and gutters) to $3,459 1000 links
Prevalence: High. 340 featured user project applications on the website
Ease of use for public utilities: Advanced
Ease of obtaining information and availability of technical support: Product information available
online. Support available through user community or service request.
Source code availability: Not available
Installation requirements/software: Not specified
Source/Link: http://www.bentley.com/en-US/Prodiicts/CivilStorm/ (Last accessed August 13. 2018)
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B.4 GWLF (Generalized Watershed Loading Function)
Developer: D.A. Haith and L.L. Shoemaker at Cornell University
Description: The GWLF is a model used to simulate runoff, sediment and dissolved and total loads of
pollutants (nitrogen and phosphorus) from complex watersheds (Haith etal., 1992). The model estimates
contaminant load from surface runoff and groundwater sources and calculates nutrient loads from point
sources and onsite wastewater disposal systems. GWLF is a combined distributed/lumped parameter
watershed model. The model is distributed in the sense that it allows multiple land use/land cover options.
Versions: v8.0
Features: The model provides monthly estimates of streamflow, soil erosion, sediment yield values and
nutrient loads. A GIS-based version of GWLF, titled AVGWLF is available from Pennsylvania State
University.
Original Application: Urban and rural
Mathematical method for flow routing and water quality: Runoff: SCS curve number method;
Infiltration: Percolation is determined using a daily water balance, and the unsaturated zone is modeled as
a simple linear reservoir; Flow Routing: Not applicable; Water Quality: Sediment erosion is modeled
using the Universal Soil Loss equation. Solid-phase rural nutrient loads are calculated by taking the
product of the monthly sediment yield and the average sediment nutrient concentrations. Urban nutrient
loads are modeled by exponential accumulation and washoff functions. Nutrient loads from septic
systems are estimated using the per capita daily load from each type of system and the number of a people
in the watershed
Input Data Requirements: Daily precipitation and temperature data, land use/land cover distribution,
coefficients (i.e., curve numbers, KLSCP factures, evapotranspiration coefficients, erosivity coefficients,
daylight hours by month, growing season months, snow amounts, N and P point source loads, background
N and P concentrations in groundwater, background P and N concentrations in soil, months of manure
spreading, and population on septic systems
Data assembly requirements during and after emergency response: Moderate
Output Data: Monthly watershed runoff, monthly streamflow, sediment and nutrient (nitrogen (N) and
phosphorus (P)) yields and loadings (monthly and annual), and calculated septic system loads
Representation of Uncertainty: None.
Hardware computing requirements: DOS, Windows
Code language: Visual Basic
Public/proprietary and Cost: Public, free
Prevalence: Moderate (GWLF has been applied in at least 12 states)
Ease of use for public utilities: Easy
Ease of obtaining information and availability of technical support: Technical support not available
Source code availability: Original code availability unknown, python version in development at:
https://githiib.com/WikiWatershed/gwlf-e (Last accessed Sept. 5, 2018)
Installation requirements/software: Not specified
Source/Link: http://www.mapshed.psu.edu/download.htm (Last accessed August 13, 2018)
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B.5 GSSHA (Gridded Surface Subsurface Hydrologic Analysis)
Developer: United States Army Corps of Engineers (USACE)
Description: GSSHA, a comprehensive watershed simulation and management model used for
hydrologic, hydraulic, sediment, and water quality simulation and management (Downer and Ogden,
2006), is a distributed, physically-based, gridded watershed model. The model can track water, sediment,
and contaminants along flow paths.
Versions: v7.0
Features: 2D overland flow, ID stream flow, ID infiltration, 2D groundwater, and full coupling between
the groundwater, vadose zones, streams, and overland flow. Provides soil moisture, runoff and flooding
predictions. Analyzes future conditions and management scenarios. Helps develop BMP and TMDL load
predictions.
Original Application: Rural
Mathematical method for flow routing and water quality: Runoff: water balance method. Infiltration:
Green-Ampt, Green-Ampt with redistribution, or Richard's equation; Evapotranspiration: Penman-
Monteith or Deardorff method; Flow Routing: 2D diffusive wave for overland flow and diffusive wave
and full dynamic wave for open channel flow; Water Quality: first order pollutant decay, dispersion, and
reactions for uptake from land surface, uptake from soil. Sediment erosion calculation methods include:
Engelund-Hansen, Kilinc Richardson, stream power, effective stream power, unit stream power, and
shear stress.
Input Data Requirements: model grid size, watershed outlet slope, map of watershed elevations and
shape, precipitation data, pollutant decay and dispersion coefficients, grain and sand size of particles,
water temperature, porosity of channel bed sediments, manning roughness, interception coefficient and
initial interception abstraction, land use, soil type, and vegetation data
Data assembly requirements during and after emergency response: High
Outputs: outflow hydrographs, overland flow depths, water surface elevations, and cumulative discharge,
sediment discharge volume and load flux and particle size in specific channel locations, groundwater head
and moisture data and contaminant transport
Representation of Uncertainty: It is possible to do Monte Carlo Runs and multiple optimization
calibration routines.
Hardware computing requirements: Runs on Windows (32- and 64-bit), Linux, and within the
supercomputing environment.
Code language: C++
Public/proprietary and Cost: Public, Free
Prevalence: Moderate. Applied in nine states of U.S.
Ease of use for public utilities: Advanced
Ease of obtaining information and availability of technical support: Product information available
online. Questions should be directed to charle s. w. downer a usace. army .mil
Source code availability: Available for download
Installation requirements/software: Compatible with GIS. Closely linked to WMS 6.1
Source/Link: https://www.gsshawiki.com/Gridded Surface Subsurface Hydrologic Analysis
(Last accessed August 13, 2018)
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B.6 HEC-HMS (Hydrologic Engineering Center-Hydrologic Modeling System)
Developer: USACE
Description: HEC-HMS is a model designed to simulate a full suite of hydrologic processes related to
dendritic watershed systems. It can perform continuous and event-based simulations of precipitation-
runoff and routing processes for natural and controlled systems. The program has been used in studies of
urban drainage, floods, and optimizing system operations.
Versions: 4.2.1
Features: HEC-HMS includes the following hydrologic elements: sub-basins, reaches, junctions,
reservoirs, diversions, sources and sinks. It also includes mathematical procedures that to account for
evapo-transpiration, snowmelt, and fluxes in soil moisture content in addition to routine runoff estimation
and routing of flows.
Original Application: Rural, urban, and suburban
Mathematical method for flow routing and water quality: Runoff: Unit hydrograph methods (Clark,
Snyder, SCS, ModClark, or user specified); Infiltration: Initial and constant loss mode, SCS curve
number loss model, Green Ampt loss model, or soil moisture accounting loss model;
Evapo-transpiration: Monthly average values, Priestly Taylor method, or Penman-Monteith method;
Flow Routing: Kinematic wave method, linear reservoir methods, or nonlinear Boussinesq method for
baseflow contributions. A lag method, Muskingum method, modified Puis method, kinematic or
Muskingum-Cunge methods for open channel flows; Water Quality: MUSLE for sediment, build-
up/wash-off, and nutrient transformations for nitrogen and phosphorus.
Input Data Requirements: Temperature index (if modeling snowmelt), net radiation (if using the
Priestley Taylor method), precipitation, reservoir/diversion discharge schedules, stage, windspeed, air
pressure, humidity, altitude, crop coefficients, sediment loads, pollutant concentrations, percolation rates,
and impervious area percentages.
Data assembly requirements during and after emergency response: High
Outputs: flow discharge, water volumes (loss, excess of reservoir storage, baseflows, discharge and
runoff), depths of water, hydrologic element peak discharge
Representation of Uncertainty: HEC-HMS provides a probability distribution function and performs a
Monte Carlo simulation to describe uncertainty in output variables
Hardware computing requirements: Windows XP, Windows Vista, Windows 7 or 10 (32-bit and 64-
bit), modern 32-bit Linus x86 distributions, or 64-bit Solaris, Intel Pentium III/800 MHz or higher,
minimum of 512 MB of member (at least 1 GB of memory recommended), 120 MB available hard disk
space for installation, and 1024 x 768 minimum screen resolution
Code language: Java
Public/proprietary and Cost: Public, free
Prevalence: High
Ease of use for public utilities: Advanced
Ease of obtaining information and av ailability of technical support: hec.hms@usace.armv.mil accepts
bug reports from the public. Support cannot be provided by USACE to individuals outside of the
USACE. Private vendors provide support for a fee (not coordinated by USACE).
Source code availability: Not freely available
Installation requirements/software: None
Source/Link: http://www.hec.iisace.armv.mil/software/hec-hms/ (Last accessed August 30, 2018)
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B.7 HSPF (Hydrological Simulation Program Fortran)
Developer: Aqua Terra, United States Geological Survey (USGS), Office of Research and Development
EPA
Description. HSPF, a continuous simulation model developed for both natural and developed watershed
and water systems (Bicknell el al. 2005), simulates land surface and subsurface hydrology, stream/lake
hydraulics, and water quality processes. It is based upon the original Stanford Watershed Model IV and a
consolidation of the Agricultural Runoff Management Model (ARM), Non-point Source Runoff (NPS)
Model and Hydrological Simulation Program (HSP) (Johnson et al., 2003). HSPF is a lumped parameter
approach (limited spatial definition) and includes a simplified representation of urban drainage system
components (pipes, culverts, Combined Sewer Overflows (CSOs), etc.). The model also provides tools
for data management and storage, statistical analysis, and operations. HSPF is the core watershed model
in EPA BASINS and Army Corps Watershed Modeling System (WMS). The model is developed and
maintained by EPA and USGS. Several user interfaces have been developed for HSPF including
WinHSPF.
Versions: vl2.2 (EPA), vl2.4 (beta, AQUA TERRA) previous: vll.O
Features: Comprehensive representation of watershed land and stream processes as well as
representation of watershed pollutant sources (including nonpoint, point, and atmospheric sources). The
model offers several modules for pre- and post-processing: HSPEXP: expert system for calibrating,
GenScn: software to change input, WDMUtil: tool to create time series data, and HSPFParm: a tool for
organizing HSPF parameter values. HSPF simulates water quality constituents such as sediment,
pesticide, nitrogen, phosphorus, and tracers for pervious and impervious surfaces, and in the stream
reaches. HSPF simulates nitrogen and phosphorus through nitrogen and phosphorus cycles, and reaction
processes of pesticides.
Original Application: Urban (and suburban)
Mathematical method for flow routing and water quality: Runoff: water balance; Infiltration: Green-
Ampt or Maryland Method (Look-up); Flow Routing, kinematic wave and Chezy-Manning equation for
overland flow (turbulent); Water Quality: Single organic chemicals and their transformation products
(hydrolysis, oxidation, photolysis, biodegradation, volatilization and sorption) can be modeled. Sorption
(only in reaches/streams) is modeled as a first-order kinetic process (user-specified desorption rate and
equilibrium partition coefficient). Sediment transport simulated for sand, clay, or silt and washoff is
modeled as an exponential function or a constant unit removal rate by overland flow. Water bodies are
assumed to be well-mixed with width and depth.
Input Data Requirements: Precipitation (hourly), temperature, evaporation, wind speed, solar radiation,
potential evapotranspiration, dew point temperature, cloud cover snow, soil properties, pollutant location
and load, land use/cover, soil properties, DEM, hydrography, watershed characterization, channel and bed
characteristics. Calibration/validation: flow, sediment, and water quality data.
Data assembly requirements during and after emergency response: High
Outputs: Flow and water quality by reach
Representation of Uncertainty: Probability distribution of inputs
Hardware computing requirements: Windows XP, Vista, Windows 7, or Windows 8
Code language: Fortran
Public/proprietary and Cost: public, free
Prevalence: High. There have been hundreds of applications of HSPF all over the world.
Ease of use for public utilities: Advanced
Ease of obtaining information and availability of technical support: Product information available
online. Technical support provided by Aqua Terra.
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Source code availability: Yes
Installation requirements/software: None
Source/Link: http://www.aquaterra.com/resources/hspfsupport/index.php
(Last accessed August 13, 2018)
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B.8 HydroCAD
Developer: HydroCAD Software Solutions LLC
Description: HydroCAD, a CAD program for modeling hydrology and hydraulics of stormwater runoff
(HydroCAD, 2011), is commonly used to generate runoff hydrographs for a given watershed and study
their flow through a drainage system. HydroCAD provides many approaches for runoff hydrograph
generation, time of concentration calculation, reach routing, pond routing and pond outlet hydraulics.
HydroCAD has over 100 predefined rainfall distributions including SCS type I, IA, II, III storms, user-
defined rainfalls, and custom synthetic rainfall distributions.
Versions: HydroCAD-10, previous versions: HydroCAD-9, 8, and 7
Features: Runoff hydrograph generation, hydrograph routing through ponds and reaches, hydraulics and
culvert calculations, advanced flow simulations including pumps and float valves, land use analysis and
pollutant loading calculations, and time-of-concentration calculations, including sheet flow method.
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff: SCS unit hydrograph method, Santa
Barbara Urban Hydrograph method, curve number lookup and weighting, rational method, or modified
rational method; Infiltration: can model using elevation-dependent rating curves; Flow Routing:
Muskingum-Cunge method or storage-indication method; Water Quality, pollutant load in runoff water is
calculated as runoff times concentrations. Pollutant load in storage facilities is calculated as a center-of-
mass detention time with plug-flow detention time.
Input Data Requirements: User defines node characteristics (subcatchment, pond, catch basin, reach, or
link). Import data directly from AutoCAD for soil groups, ground covers, subcatchment boundaries or
using an additional program called Carlson Hydrology (Maysville, KY, USA) for additional parameters
(i.e., watershed slope and pond storage contours from .dwg files)
Data assembly requirements during and after emergency response: Moderate
Output: Runoff and water quality. Import or export to Comma Separated Values (CSV) format.
Representation of Uncertainty: Uncertainty can be modeled using model scenarios
Hardware computing requirements: Runs on any PC under windows 95, 98, NT, ME, 2K, XP, Vista,
Windows 7, or later
Code language: Object Pascal (Delphi Compiler)
Public/proprietary and Cost: proprietary, $275 (5 nodes) - $2200 (1000 nodes)
Prevalence: Moderate
Ease of use for public utilities: Moderate
Ease of obtaining information and availability of technical support: Technical support available
through user forum or service request.
Source code availability: Not available
Installation requirements/software: CD installation. Does not require other CAD software.
Source/Link: www.lndrocad.net (Last accessed August 13, 2018)
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B.9 InfoSWMM
Developer: Innovyze
Description: InfoSWMM is a modeling system that simulates hydrologic, hydraulic, and water quality in
urban and rural areas and uses EPA's SWMM5 computational engine. InfoSWMM is built on top of the
ArcGIS platform as an extension to ArcGIS. InfoSWMM models a variety of hydraulic, hydrologic, and
water quality processes for any number of user-defined constituents, including conservative and reactive
substances, and load reduction due to BMPs, LIDs, and sustainable urban drainage systems (SUDS).
Version: vl4.6
Features: Includes all the features of EPA SWMM5 as well as offers an advanced real-time control
(RTC) scheme for the management of hydraulic structures. InfoSWMM has several extensions, including
InfoSWMM Calibrator for model calibration, InfoSWMM DWF allocator for dry weather flow analysis,
InfoSWMM Conduit Storage Synthesizer (CSS), InfoSWMM Suite for Subcatchment delineation,
InfoSWMM Risk Assessment Manager (RAM) for overflow and flooding risk analysis. In addition,
several add-on tools are available, including InfoSWMM2D for 2D flood modeling, InfoSWMM SFEM
(Sewer Flow Estimation Model) for wastewater master planning, and InfoSWMM Sustain for evaluating
BMP, LID, and SUDS.
Original Application: Urban (and suburban)
Mathematical method for flow routing and water quality: Runoff: water balance/SCS curve number
method and a number of hydrograph methods including NRCS, Clark, Snyder, Santa Barbara, Delmarva,
Espy, and triangular; Infiltration: Over 17 hydrology methods including Horton's method, Modified
Horton method, Green-Ampt method, Modified Green-Ampt method, and the SCS curve number method;
Flow Routing: steady flow routing, kinematic wave routing, or dynamic wave routing; Water Quality:
pollutant build-up is simulated using a power function, an exponential function, a saturation function, or
an external time series. Washoff of pollutants is simulated using an exponential function, rating curve, or
an event mean concentration approach.
Input Data Requirements: Like EPA SWMM but also requires a DEM and boundary layer information
for 2D modeling extension
Data assembly requirements during and after emergency response: High
Outputs: Subcatchment variables (e.g., rainfall, runoff), node variables (e.g., water depth, hydraulic
head), link variables (e.g., flow rate, water depth), system-wide variables (e.g., air temperature,
evaporation, total rainfall, snow depth)
Representation of Uncertainty: Although no uncertainty module is provided, uncertainty can be
propagated through the model by using distributions of input variables or by using alternative scenarios
Hardware computing requirements: Windows server 2008 R2, Windows 7 Pro or above, Windows
Server 2012, Windows Internet Explorer 7 or later, ArcGIS 10.0-10.6, Microsoft Visual C++ 2008 or
2010. CPU speed: 2.2 GHz minimum or higher, Processor: Intel Pentium 4, Intel Core duo, orXeon
processors, SSE2. Memory/RAM: 2 BG or higher. Screen resolution: 1024 x 768 recommended or higher
at normal size. Disk Space: 500 Mb of free space Video/Graphics Adapter: 64 MB RAM minimum, 256
MB RM or higher. Network Hardware: simple TCP/P.
Code language: Microsoft Visual C++ 2008
Public/proprietary and Cost: Proprietary, $1,000- $25,000 depending on application (also need
ArcGIS)
Prevalence: High
Ease of use for public utilities: Advanced
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Ease of obtaining information and availability of technical support: Product information available
online. Formal customer support and software maintenance offered by Innovyze.
Source code availability: Code available to licensee for the open source components only
Installation requirements/software: Compatible withArcGIS 10.0 to 10.6
Source/Link: http://www.innovvzc.com/products/infoswmm/ (Last accessed August 13, 2018)
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B.10 INFOWORKS ICM (INFOWORKS INTEGRATED CATCHMENT MODELING)
Developer: Innovyze
Description: Infoworks ICM (Integrated Catchment Modeling) is a ID and 2D simulation model for
above- and below- ground drainage networks (Walker, 2012). The model simulates ID hydrodynamics of
flows in rivers, open channels, and pipe networks and 2D hydrodynamics of surface flooding in urban
environments and river floodplains. The model can import Hydrologic Engineering Center - River
Analysis System (HEC -RAS) channel geometry and perform surface flow routing using 2D modeling.
The model has been used in river, drainage, and sewerage master planning studies, development of
surface water management plans, implementation of SUDS and BMPs, and to assess the impact of
intermittent discharges from sewerage systems (sanitary sewer overflows and combined sewer overflows;
CSOs) on river environments.
Versions: v9.5.2
Features: Full 2D surface flood modeling can be employed across both the wastewater and river
components of the model. Real-time control allows control structures to be programmed into the system
during a simulation. Water quality and sedimentation studies can be carried out across both ID and 2D
areas. The ID river channels are linked to 2D floodplains.
Original Application: Urban
Mathematical method for flow routing and water quality: ICM has its own proprietary implicit
solution and over 35 different hydrology and infiltration methods that are used globally. Components
from SWMM5 include SWMM5 Runoff, Green Ampt and SWMM Horton Infiltration, LID components
called SUDS, snowmelt and Rainfall Dependent Infiltration and Inflow (RDII).
Input Data Requirements: Like EPA SWMM (B. 1) but also requires a digital elevation model and
boundary layer information for 2D modeling extension
Data assembly requirements during and after emergency response: High
Output: Flood flow velocity, depth, debris potential, flood risk map, property flooding. Seamless
exchange of data and result to and from GIS, Excel and Access, data exchange via Open Data
Import/Export Centre.
Representation of Uncertainty: Can be modeled using comparison of different model scenarios
Hardware computing requirements: Designed for Windows 10/8/7, Windows Vista and Windows XP.
Supports all 64-bit operating systems.
Code language: Unknown
Public/proprietary and Cost: Proprietary, estimated to be $50,000- $75,000 (5000 nodes - unlimited
nodes) from online sources
Prevalence: Moderate. Ten case studies, many testimonials on developer's website
Ease of use for public utilities: Advanced
Ease of obtaining information and availability of technical support: Support from Innovyze available
Source code availability: Not available
Installation requirements/software: ESRI ArcGIS 9.3, 10.0-10.6. Maplnfo Professional 10.5 or above.
Source/Link: http://www.innovvzc.com/products/infoworks icm/ (Last accessed August 14. 2018)
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B.11 LSPC (Loading Simulation Program in C++)
Developer: Tetra Tech, under contract to National Exposure Research Laboratory, Office of Research
and Development (EPA)
Description: LSPC, Loading Simulation Program in C++, is a watershed modeling system that
incorporates HSPF algorithms for simulating hydrology, sediment and water quality on watersheds and
water bodies. The LSPC model provides a GIS- integrated user interface for HSPF. LSPC was a primary
watershed model for the EPA TMDL modeling toolbox. The in-stream model of LSPC has been
expanded to include HSPF GQUAL components and the HSPF RQUAL module for simulating dissolved
oxygen (DO), nutrients and algae (Tetra Tech, 2009). LSPC has been customized to simulate other
pollutants such as nutrients and fecal coliform. LSPC uses a Microsoft (MS) Access database to manage
model input files and an editable weather text file for managing the weather data.
Versions: v3.1
Features: Land surface and subsurface hydrology and quality. Stream/lake hydraulics and water quality.
Sediment production and removal. GIS integration. MS Access database to manage model configuration
and parameterization data. Output linked to other models such as EFDC, WASP, and CE-QUAL-W2.
Original Application: Mixed land use
Mathematical method for flow routing and water quality: See HSPF model (B.7)
Input Data Requirements: Same as in HSPF model, but streamlines user input interfaces (B.7)
Data assembly requirements during and after emergency response: moderate
Outputs: Flow and water quality by reach. Output from LSPC linked to EFDC, WASP and CE-QUAL-
W2. Microsoft Access and Excel
Representation of Uncertainty: Probability distribution of inputs
Hardware computing requirements: IBM-compatible personal computers (PCs). Processor: Pentium II-
500 MHz. Hard drive space: 500 MB. Random access memory (RAM): 128 MB, compact disc drive: CD-
ROM 4x, operating system: Windows 98, 2000, or NT.
Code language: MS Visual C++
Public/proprietary and Cost: Public and free
Prevalence: High. Widely applied applications throughout the US (desert, alpine, temperate)
Ease of use for public utilities: Advanced
Ease of obtaining information and availability of technical support: User manual available online
with EPA contact information.
Source code availability: Yes
Installation requirements/software: ArcGIS, Microsoft Access/Excel
Source/Link:https://cfpub.epa.gov/si/si public record Report.cfm?dirEntrvId=75860&CFID=22884508&C
FTOKEN=98267566 (Last accessed August 14. 2018)
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B.12 MapShed
Developer: Penn State Institutes of Energy and the Environment (PSIEE)
Description: MapShed is a GIS version of the GWLF model (Evans and Corradini, 2012). MapShed
duplicates the functionalities from another GIS version of the GWLF (AVGWLF, Evans et al., 2002). The
GIS interface of MapShed is provided by a free MapWindow GIS software package, while AVGWLF
uses the ArcView 3.x GIS package developed by ESRI. Like AVGWLF, MapShed provides a link
between the GIS software and the enhanced version of the GWLF watershed model.
Versions: vl.3
Features: GIS-based derivation of model input data with enhancements of the original code to include
urban best management practice modeling including detention basin, infiltration, bioretention, vegetative
buffer strips, constructed wetlands, streambank stabilization, impervious surface reduction, and street
sweeping.
Original Application: Rural
Mathematical method for flow routing and water quality: See GWLF (see B.17)
Input Data Requirements: See GWLF (see B.17)
Data assembly requirements during and after emergency response: Moderate
Outputs: See GWLF (see B.17)
Representation of Uncertainty: None.
Hardware computing requirements: PC with Pentium or higher, 24 MB RAM, Windows 98/98SE,
ME, 2000, XP or newer, 2003 server, 1024 x 768 pixels or higher resolution screen and >200 MB disk
space, with > 4GB preferred
Code language: VB.net
Public/proprietary and Cost: Public, free
Prevalence: Low (applied in several states)
Ease of use for public utilities: Easy
Ease of obtaining information and availability of technical support: Email support available for
questions on the model
Source code availability: http://www.mapshed.psu.edu/download.htm
Installation requirements/software: MapWindow Ver. 4.6
Source/Link: http://www.mapshed.psu.edu/index.htm (Last accessed August 14. 2018)
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B.13 MIDS (Minimal Impact Design Standards) calculator
Developer: Minnesota Pollution Control Authority (MPCA)
Description: The MIDS BMP calculator is a spreadsheet-based tool designed to manage stormwater
using a low-impact development approach (Barr, 2014, 2011). The MIDS model determines volume and
pollutant reduction capabilities of various LID BMPs.
Versions: v2
Features: MIDS includes design specifications for a variety of green infrastructure BMPs, a credit
calculator, and model ordinances for communities that support clean water goals. MIDS can model 16
green infrastructure BMP types including green roofs, bioretention basins, infiltration basins, permeable
pavement, tree trenches, swales, cisterns, sand filters, constructed stormwater ponds, constructed
wetlands, and several other user defined reductions.
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff/Infiltration: SCS runoff curve
number method; Flow Routing: Not applicable; Water Quality: Pollutant load calculations use event
mean concentrations.
Input Data Requirements: Site information such as area, percent area impervious surface, land cover
classifications, soil type, precipitation, and pollutant (e.g., phosphorus and TSS) event mean
concentrations.
Data assembly requirements during and after emergency response: Low
Outputs: Runoff volume removed by specified BMP, additional volume removal needed to meet local
ordinance, and annual and percentage phosphorous and total suspended solid loading removed.
Representation of Uncertainty: None.
Hardware computing requirements: Not specified
Code language: Visual Basic (VB)
Public/proprietary and Cost: Public, free
Prevalence: Low. Several applications in MN and MI.
Ease of use for public utilities: Easy
Ease of obtaining information and availability of technical support: A "super users" contact list
available for questions at link provided below.
Source code availability: Yes
Installation requirements/software: Microsoft .Net Version 4.0 framework. Requires Excel 2003 or
later
Source/Link: http://stormwater.pea.state.mn.us/inde\.php/MIDS calculator
(Last Accessed August 29, 2018)
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B.14 Mike Urban
Developer: DHI
Description: MIKE URBAN is an urban water software model with GIS integration (DHI, 2017). MIKE
URBAN models all aspects of water networks in the city, including water distribution, stormwater
drainage, and sewer collection in separate and combined systems. The model can be used for drinking
water management including master planning, flow analysis, water quality risk analysis, and wastewater.
MIKE URBAN is also used for stormwater analysis, evaluation of storm water BMPS and LIDs, and
design and optimization of real-time controls. MIKE URBAN's water distribution components are based
on the EPANET engine and DHI's engine for transient flows, allowing simulation for modeling water
distribution networks. Collection System (CS) modules are based on DHI's MOUSE, MIKE ID or
SWMM engines. MIKE URBAN combines overland river and pipe flow modeling, allowing modeling
floods in the urban environment. The model combines groundwater and pipe flow modeling, allowing
modeling infiltration to and leakage from pipes.
Versions: MIKE URBAN 2016
Features: Flood modeling in urban areas. CSO analysis and flood mitigation in urban areas. Coupling of
ID sewer model with 2D overland flow model. Dynamic linkage to rivers, lakes, streams and estuaries.
Sustainable planning of urban infrastructures. Groundwater modeling (2D/3D).
Original Application: Urban
Mathematical method for flow routing and water quality: MIKE URBAN includes the SWMM5
engine (see B.l). It also includes DHI's proprietary MOUSE engine which uses the following options:
Runoff: Unit Hydrograph method (Rational method or SCS curve number method), time area curve
characteristic method, linear reservoir, or a non-linear reservoir approach; Infiltration: Horton method or
Integrated Horton method; Flow Routing: an implicit finite-difference numerical solution of the Saint
Venant (dynamic flow) equations; Water Quality: The MOUSE engine includes four sediment transport
models (Ackers-White, Engclund-Frcdsoe. Engelund-Hansen, and van Rijn) as well as correction factors
for graded sediments and thin layers of sediment in pipes. It also uses a one-dimension, vertically-
integrated equation for conservation of mass of dissolved substances and solves the advection-dispersion
equation for pipes, manholes, pumps, and weirs. Biological processes of water quality components can be
modeled using ECO Lab coupled to the Mike ID hydraulic engine.
Input Data Requirements: DEM, rainfall, drainage network, nodes and structure geometries: manholes,
pipes, canals, orifices, weirs. Buildup, washoff, detachment rate.
Data assembly requirements during and after emergency response: High
Outputs: Hydraulic modeling results (velocity, flow rate, depth of water) for overland flow, sewer flow,
and groundwater as well as water quality data. The outputs can be integrated with other DHI standalone
products such as MIKE 21, MIKE 11, and MIKE SHE for mapping and visualization.
Representation of Uncertainty: Specified in input variable (e.g. rainfall) using the stochastic method
can be propagated through the model (Rene et al. 2012)
Hardware computing requirements: Windows 7 Professional Service Pack 1 (32- and 64-bit),
Windows 8.1 pro (64-bit), Windows 10 Pro (64-bit), and Windows Server 2012 R2 Standard (64-bit).
X86 or x64, 2.2 GHz (or higher), 2GB memory Random Access Memory (RAM), 40 GB hard disk, 64
MB RAM, and Super Video Graphics Array (SVGA) monitor, resolution 1024 x 768 in 16-bit color
Code language: C++ and C#
Public/proprietary and Cost: Proprietary; $18,000 - $25,000
Prevalence: High. 11 references on the website. Many applications in the literature.
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Ease of use for public utilities: Advanced
Ease of obtaining information and availability of technical support: Product information available
online. Client care team available for technical assistance, installation, producing updates and licenses,
and software maintenance.
Source code availability: Not available
Installation requirements/software: .Net Framework 3.5 SP1 and .Net Framework 4.0. ArcGIS 10.3
Source/Link: http://www.mikebvdhi.com/Products/Cities/MIKEURBAN.aspx
(Last accessed August 14, 2018)
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B.15 P8 (Program for Predicting Polluting Particle Passage through Pits,
Puddles, and Ponds)
Developer: W W. Walker and J.D. Walker
Description: P8 simulates the generation and transport of stormwater pollutants in urban watersheds. The
model uses water balance and mass balance summations to simulate drainage elements of watersheds,
control devices, particles, and water quality components. P8 simulations are based on hourly precipitation
and daily air temperature time series. The model was developed for designing and for evaluating runoff
for existing or proposed urban developments. P8 has been used by state and local agencies as a
framework to evaluate proposed developments. Predicted water quality components of the model include
total suspended solids (TSS), total phosphorus (TP), total Kjeldahl nitrogen (TKN), copper (Cu), lead
(Pb), zinc (Zn), and total hydrocarbons. Simulated BMP types include detention ponds (wet, dry,
extended), infiltration basins, swales, buffer strips, or other devices. A simple water budget algorithm is
used to estimate groundwater storage and stream base flow.
Versions: v3.5
Features: Predicted water quality components include TSS, TP, TKN, Cu, Pb, Zn, and total
hydrocarbons. Simulated BMP types include detention ponds, infiltration basins, swales, buffer strips, or
other devices.
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff: SCS curve number method;
Infiltration: difference between rainfall and runoff (rainfall -runoff); Flow Routing: Not applicable;
Water Quality: Pollutant washoff is simulated using an exponential function (dB/dt = -aBr where a =
washoff coefficient, B = buildup or accumulation on impervious surface, r = runoff intensity, and c =
washoff exponent.
Input Data Requirements: Precipitation, temperature, watershed data: land use, total area, impervious
fraction, impervious depression storage, impervious runoff coefficient, street-sweeping frequency, SCS
runoff curve number for pervious portion. Devices: dimensions, outlet configuration, infiltration rates,
slope, roughness. Specific inputs vary with device type: detention pond, infiltration basin, swale/buffer,
pipe/manhole, splitter, and aquifer. Particle inputs: accumulation/washoff parameters, runoff
concentrations, street-sweeper efficiencies, settling velocities, decay rates, filtration efficiencies to
account for removal via infiltration.
Data assembly requirements during and after emergency response: Low
Outputs: Flow, TSS loads, concentrations, particle loads, concentration. Compatible with Microsoft
Excel
Representation of Uncertainty: Not specified.
Hardware computing requirements: PC with Microsoft Windows 10 operating system
Code language: Visual Basic 2005
Public/proprietary and Cost: Public, free.
Prevalence: Moderate. P8 has been used by state and local agencies for evaluating proposed
developments.
Ease of use for public utilities: Moderate
Ease of obtaining information and availability of technical support: Product information available
online. Technical support is available for a fee.
Source code availability: Unknown
Installation requirements/software: Microsoft Excel. Microsoft Net Version 4.5
Source/Link: http://www.wwwalker.net/p8/ (Last Accessed August 29, 2018)
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B.16 PCSWMM
Developer: CHI
Description: PCSWMM is a spatial modeling system that supports hydrology and hydraulic modeling.
The model uses EPA's SWMM5 computational engine (www.chi.com; James et al. 2012; James et al.
2013). PCSWMM is a stand-alone application that provides a GIS engine and expanded code and tools to
work with spatial data for model development and analysis. Of note, PCSWMM expands EPA SWMM5
for flood modeling. The model provides simulation of ID and 2D overland flow. PCSWMM is commonly
used in drainage and green infrastructure design, floodplain delineation, sewer overflow mitigation, water
quality and catchment analysis, and 1D-2D modeling.
Versions: v7.1
Features: Includes all the features of EPA SWMM5 as well as supporting popular open standard and
proprietary GIS/CAD formats and numerous specialized tools to aid in model auditing, connectivity, and
calibration. PCSWMM can perform 2D modeling whereas EPA SWMM5 cannot.
Original Application: Urban (and suburban)
Mathematical method for flow routing and water quality: Runoff: water balance; Infiltration:
Horton's method, Modified Horton method, Green-Ampt method, Modified Green-Ampt method, Curve
number method; Flow Routing: steady flow routing, kinematic wave routing, or dynamic wave routing;
Water Quality: pollutant buildup is simulated using a power function, an exponential function, a
saturation function, or an external time series. Washoff of pollutants is simulated using an exponential
function, rating curve, or an event mean concentration approach.
Input Data Requirements: Like EPA SWMM but also requires a DEM and boundary layer information
for 2D modeling.
Data assembly requirements during and after emergency response: High
Outputs: Subcatchment variables (e.g., rainfall, runoff), node variables (e.g., water depth, hydraulic
head), link variables (e.g., flow rate, water depth), system-wide variables (e.g., air temperature,
evaporation, total rainfall, snow depth).
Representation of Uncertainty: Specified for input variables, and input range can be used in model
calibration.
Hardware computing requirements: Requires the Microsoft Windows 10, 8, 7, Vista, or XP (SP2)
operating system, with the Microsoft .NET 4.5 framework installed. Minimum screen resolution of
1024x768 pixels (XGA), a minimum of 2 GB of physical memory and 100 MB of disk space.
Code language: C# for .NET, utilizing many new techniques (e.g., Google Earth, Web documentation)
Public/proprietary and Cost: SWMM engine code is public, PCSWMM specific code is proprietary;
Professional: $120/per user/month, professional 2D: $180 per user/month, Enterprise: $4,000 per year +
$40 per user/month
Prevalence: High; 5,000+ users
Ease of use for public utilities: Moderate/advanced
Ease of obtaining information and availability of technical support: Knowledge base online, technical
support from professional engineers of CHI.
Source code availability: Hydrology/Hydraulics engine is in public domain, source code viewer for the
engine available online
Installation requirements/software: No third-party software is required
Source/Link: https://www.pcswmm.com/ (Last Accessed August 29th, 2018)
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B.17 SELDM (Stochastic Empirical Loading and Dilution Model)
Developer: USGS/Federal Highway Administration (FHA)
Description: The Stochastic Empirical Loading and Dilution Model (SELDM) is a stochastic spreadsheet
model designed to estimate event mean concentrations, flows, and loads in stormwater from a site of
interest and from an upstream basin (Granato, 2013; Granato and Jones, 2014). These derived values are
planning-level estimates that can be used to evaluate alternative management measures and are subject to
large uncertainties. SELDM is a lumped parameter model because each site or lake basin is represented as
a single homogeneous unit. It was developed as a Microsoft Access database software application.
Versions: vl.0.3
Features: SELDM is a stochastic empirical loading and dilution model that uses site information and data
associated with receiving water basin, precipitation events, stormflow, water quality and mitigation
measures to calculate a stochastic population of runoff-quality variables. The model uses Monte Carlo
methods to produce random combinations of input variables that are used to generate the stochastic
population of values of interest.
Original Application: Rural
Mathematical method for flow routing and water quality: SELDM is an empirical model based on
data and statistics rather than theoretical equations. Runoff/Infiltration: SCS curve number method and
triangular runoff hydrographs; Flow Routing: Not applicable; Water Quality: Loads from highways and
the upstream basin are simulated using stochastically generated random runoff concentrations and flows.
Input Data Requirements: SELDM requires the latitude and longitude of the study site, area,
imperviousness, main channel length, main channel slope, and basin development factor for the highway
site and the site of interest. Also requires representative event mean concentrations for water quality
parameters for the site of interest and the upstream basin.
Data assembly requirements during and after emergency response: Low
Outputs: Stochastic population of flows and pollutant loads
Representation of Uncertainty: Monte Carlo methods are used to produce random combinations of
input variable values
Hardware computing requirements: Limited to Windows operating systems. The graphical display
forms require a screen resolution exceeding 1024 x 768 pixels.
Code language: Visual Basic for Application
Public/proprietary and Cost: Public, free
Prevalence: Moderate. Tested and reviewed by 43 professionals and 16 state agencies.
Ease of use for public utilities: Easy
Ease of obtaining information and availability of technical support: Questions on the model can be
emailed to ggranato@usgs.gov
Source code availability: Yes
Installation requirements/software: Microsoft Access
Source/Link: https://newengland.water.usgs.gov/dev/gl/Software/SELDM/index.html
(Last accessed August 14, 2018)
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B.18 SELECT (BMP System Effectiveness and Life-Cycle Evaluation of Costs
Tool)
Developer: WERF
Description: The SELECT model is a simple planning and screening tool developed to evaluate
alternative BMP scenarios (WERF, 2013; Moeller, 2010). It is an Excel spreadsheet tool that is comprised
of: 1) a simulation module that simulates pollutant load expected in receiving water using BMP
performance data, and 2) a cost analysis module based upon WERF's Whole Life Cycle Model for BMPs.
The goal of the model is to link the BMP control effectiveness to cost information to improve selection
and design of BMP systems. The model provides life cycle costs of BMPs including: capital costs,
operational and maintenance costs, and replacement costs.
Versions: v2.0
Features: Simulated BMPs: extended detention, bioretention, wetland basin, swale, permeable pavement,
and filter and generic BMP. Simulated water quality parameters: TSS, TKN, TP, Zn, Cu, fecal coliform.
Original Application: Rural
Mathematical method for flow routing and water quality: Runoff/Infiltration: SCS curve number
method; Flow Routing: Not applicable; Water Quality: Pollutant loads are calculated using event mean
concentrations (EMCs). Land use EMC values come from the National Stormwater Quality Database and
BMP EMC values from bmpdatabase.org.
Input Data Requirements: Local rainfall data, local evaporation data, watershed area, watershed land
use type, BMP type, BMP drawdown time. Inputs to improve accuracy: land use characteristics, water
quality capture volume, local stormwater characteristics, local BMP performance parameters, local BMP
costs. The model provides default values for watershed parameters for each land use (% impervious,
runoff coefficient, depression storage, average phosphorus), default BMP parameters (% loss, average
phosphorus, average nitrogen concentrations).
Data assembly requirements during and after emergency response: Low
Outputs: Total runoff volume, annual pollutant loads by watershed, pollutant load frequency curves with
uncertainty estimates, whole life cost of BMPs
Representation of Uncertainty: Pollutant load frequency curves with uncertainty estimates
Hardware computing requirements: Windows 10 preferred (XP or windows 7 generally work, but the
software is not optimized for these platforms)- either 32 - or 64-bit; Office 2007 or Office 2010 - must be
32-bit
Code language: VBA
Public/proprietary and Cost: Public, free
Prevalence: Moderate (SELECT has been used in 12 case studies in the US)
Ease of use for public utilities: Easy
Ease of obtaining information and availability of technical support: A SELECT user support website
is available to assist users.
Source code availability: Yes
Installation requirements/software: Microsoft Excel 2010 32-bit version (Generally performs well with
Excel 2007 32-bit version, but not optimized for this platform)
Source/Link: http://www.werf.org/i/c/Tools/SELECT.aspx ("Last accessed August 29, 2018)
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B.19 SHSAM (Sizing Hydrodynamic Separators and Manholes)
Developer: Barr Engineering
Description: SHSAM is a computer program written to specialize in predicting the effectiveness of
stormwater control measures (SCMs) in removing sediment loads from stormwater runoff. SHSAM is
based on data collected at the Saint Anthony Falls Laboratory at the University of Minnesota on full-scale
testing of different flow-through structures.
Versions: v6.60
Features: SHSAM can model the following SCMs: BaySaver (IK), CDS (PMSU20_15), Downstream
Defender (6-ft), ecoStorm (Model 3), Envronment21 (V2B1 Model 4), Stormceptor (STC4800), Standard
Sumps 6x6, 6x3, 4x4, 4x2, Standard Sumps with SAFL Baffle (6x3, 4x4), Vortechs System (Model
2000), SciClone (SC-4). SHSAM does not simulate snowfall, snowpack, and snowmelt in runoff
hydrographs
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff: SCS curve number method with S-
hydrograph; Infiltration: Implements an abstraction term; Flow Routing: not applicable; Water Quality:
SHSAM uses a generic sediment removal response function based on experimentally collected data and a
washout function (Vogel et al. 2013; Bonnema et al. 2014).
Input Data Requirements: climate data (precipitation, temperature), watershed data (drainage area,
percent impervious, hydraulic length, average slope, curve number), particle information (particle size,
sediment percent finer, specific gravity) and influent concentration of suspended solids.
Data assembly requirements during and after emergency response: Low
Outputs: Particle size fraction removal summary, runoff volumes, total suspended solids removal
Representation of Uncertainty: None
Hardware computing requirements: None specified
Code language: C
Public/proprietary and Cost: Public, free
Prevalence: Low. (SHSAM has been applied to several lakes in Minnesota)
Ease of use for public utilities: Low
Ease of obtaining information and availability of technical support: Low, limited information
available
Source code availability: Not available
Installation requirements/software: Not specified
Source/Link: https://www.barr.com/WhatsNew/SHSAM/SHSAMapp.asp
(Last accessed August 14, 2018)
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B.20 STEPL
Developer: EPA
Description: The Spreadsheet Tool for Estimating Pollutant Loads (STEPL) is a customized MS Excel
spreadsheet model designed to support planning level decision-making (Tetra Tech, 2011). The model
uses simple algorithms to calculate nutrient and sediment loads from different land uses and aggregates
them by watershed. The model also calculates load reductions because of implementing BMPs. The land
use types that can be modeled in STEPL include urban, cropland, pastureland, feedlot, forest, and a user-
defined option. STEPL also offers a data server for deriving land use data based on location and weather
data for each state.
Versions: v4.3
Features: Runoff calculation, sediment erosion and pollutant load, load reduction by BMPs. STEPL
offers capabilities to simulate many types of BMPs for cropland, pasture land, urban land, and septic
systems.
Original Application: Rural
Mathematical method for flow routing and water quality: Runoff: SCS curve number method;
Infiltration: The SCS coefficients are adjusted by soil group; Flow Routing: Not applicable; Water
Quality: The annual nutrient loads are calculated based on runoff volume and pollutant concentrations in
the runoff water as influenced by factors such as the land use and management practices. The annual
sediment load is calculated based on the Universal Soil Loss Equation (USLE) and the sediment delivery
ratio.
Input Data Requirements: Local precipitation, land use distribution, agricultural animal population
numbers, number of months manure applied, number of populations using a septic system, septic tank
failure rate, direct wastewater discharges, irrigation amount/frequency, BMP type and % area applied.
Data assembly requirements during and after emergency response: Low
Outputs: Runoff volume, groundwater volume, sheet/rill erosion loads, and pollutant load by land use
and load reductions by watershed of N, P, Biochemical Oxygen Demand (BOD) and sediment at
watershed level.
Representation of Uncertainty: None
Hardware computing requirements: Windows 7 or 10, Microsoft Excel 2013 or 2016, 40 MB hard disk
space
Code language: Visual Basic (VB)
Public/proprietary and Cost: Public, free
Prevalence: Low. Several applications.
Ease of use for public utilities: Easy
Ease of obtaining information and availability of technical support: Product information available
online. Email support available.
Source code availability: Unknown
Installation requirements/software: Microsoft Excel 2010 or 2013
Source/Link: http://it.tetratech-ffx.com/steplweb/models$docs.htm (Last accessed August 14. 2018)
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B.21 StormNET
Developer: BOSS International
Description: StormNET is a dynamic hydrology and hydraulic model that can analyze highway drainage
systems, stormwater sewer networks, automatic sizing and designing of detention ponds, bridge and
culvert modeling, water quality studies, and sanitary sewers. The model is AutoCAD- and GIS-integrated.
StormNET uses a rainfall designer that provides design storm rainfall for any location within the United
States (US). The model has been renamed Storm and Sanitary Analysis in AutoCAD Civil 3D developed
by AutoDesk
Versions: Part of AutoCAD Civil3D 2017
Features: Full-dynamic hydrology and hydraulic model that can analyze both simple and complex
stormwater systems. Integration with AutoCAD land desktop and Civil 3D. Automated detention pond
design. Incorporates BMPs. Based upon an enhanced version of the latest USEPA SWMM. Includes
bridge and culvert modeling
Original Application: Urban (and suburban)
Mathematical method for flow routing and water quality: Runoff/Infiltration: EPA SWMM 5.0
approach, SCS curve number method, rational method, modified rational method, DeKalb rational
method and hydrograph methods: Santa Barbara Unit Hydrograph, Delmarva Unit Hydrograph; Flow
Routing: Kinematic and dynamic wave methods; Water Quality, pollutant build up and washoff via
exponential, rating curve, or EMCs.
Input Data Requirements: hydrology data: rain gauges, sub-basin data, groundwater aquifers. Hydraulic
data: Nodes (junctions, outfalls, flow diversion, inlets, storage nodes) and links (conveyance links,
pumps, orifices, weirs, outlets) data. Water quality data: pollutants and land uses. Curve data: storage
curves, flow diversion curves, outfall tidal curves, pump curves, outlet rating curves.
Data assembly requirements during and after emergency response: Moderate
Outputs: flow rates, velocities, hydraulic grades, water quality concentrations.
Representation of Uncertainty: None.
Hardware computing requirements: CPU: 1 GHz or faster 64-bit processor, 4 GB memory, 1360 x 768
display resolution, display card: 1360 x 768 with true color capabilities, disk space: 10.0 GB
Code language: AutoCAD .NET Application Programming Interface (API), .Net API, .COM API,
Custom Draw API (in C++).
Public/proprietary and Cost: Proprietary: $2,100/year, $3,990/2 years, $5,670/3 years, $265/month for
Civil 3D.
Prevalence: Moderate
Ease of use for public utilities: High
Ease of obtaining information and availability of technical support: Product information available
online. Email or phone support available.
Source code availability: Proprietary
Installation requirements/software: Microsoft Windows 10, .Net Framework Version 4.6
Source/Link: http://www.bossintl.com/html/stormnet-overview.html (Last accessed August 14, 2018)
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B.22 SWAT (Soil and Water Assessment Tool)
Developer: USDA Agricultural Research Service (ARS) and Texas A&M AgriLife Research
Description: SWAT is a watershed and river basin model developed by the USDA Agricultural Research
Service (ARS; Neitsch et al. 2009). SWAT was developed to predict impacts of land management
practices on water, sediment and pollutant yields from watersheds. The model simulates physical
processes associated with water movement, sediment erosion, crop growth and nutrient cycling. The
pathways of water movement simulated by SWAT include: canopy storage, infiltration,
evapotranspiration, lateral subsurface flow, surface runoff, ponds, channels and return flow. SWAT also
tracks the movement and transformation of several forms of N and P in the watershed.
Versions: ArcSWAT 2012.10.19 for ArcGIS or MWSWAT or SWAT2012 rev. 664 stand alone
Features: SWAT is a physically based model that uses readily available inputs and simulates impacts of
land management practices. Simulated BMPs include filter strips and grassed ID waterways. There are
many versions of SWAT depending on user interface: ArcSWAT based on ArcGIS, QSWAT based on
QGIS interface, MWSWAT based on MapWindow, and AVSWAT based on ArcView GIS. SWAT also
offers tools for model output visualization and analysis such as IZSWAT and SWAT Check. SWAT-
MODFLOW links SWAT with MODFLOW.
Original Application: Agricultural, rural
Mathematical method for flow routing and water quality: The hydrologic cycle simulated by SWAT
is based on the water balance equation. Runoff: Runoff rate is estimated by a modified rational
method/the NRCS TR-55 method; Infiltration: Green Ampt; Evapotranspiration: Penman-Monteith,
Hargreaves, or Priestly-Taylor; Flow Routing: Manning's equation is used for flow and average velocity
calculations in channels, Muskingum routing method for reservoirs; Water Quality: Nutrient components
are modeled through nitrogen and phosphorus cycles. For pesticides, washoff, degradation, and leaching
processes are modeled. Bacteria are modeled through washoff, die-off and regrowth, and leaching
processes. Sediment erosion is modeled through the modified universal soil loss equation (MUSLE) and
Bagnold's equation to predict degradation of stream linings.
Input Data Requirements: Watershed input files with routing and land parameters defined,
precipitation, temperature, solar radiation, wind speed, relative humidity, potential evapotranspiration,
weather forecast, land cover/plant growth, pesticide, fertilizer, urban pollutant buildup/washoff, septic,
subbasin, pond/wetland, water use, soil chemical and physical characteristics, and main water channel
parameter files. The model also requires water quality files associated with QUAL2E transformations in
main channels and streams.
Data assembly requirements during and after emergency response: High
Outputs: Flow (surface runoff, lateral flow contribution to streams, groundwater, water percolation,
drainage tile, stored soil water, actual and potential evapotranspiration, water yield) and water quality
(sediment yield, nitrate loadings, plant uptake of N, soluble and organic phosphorus loadings, ammonia
distributions in flow and solids and changes in bacterial loadings) by sub-catchbasin.
Representation of Uncertainty: Offers automated method for uncertainty analysis/auto-calibration. Use
SWAT-CUP as a calibration, uncertainty, or sensitivity program.
Hardware computing requirements: 2 GB free space if using 32-bit system.
Code language: FORTRAN
Public/proprietary and Cost: Public, free
Prevalence: High. One of the most widely used models, with hundreds of applications reported.
Ease of use for public utilities: Advanced
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Ease of obtaining information and availability of technical support: Product information available
online. User support available from user groups and development team.
Source code availability: Yes. Source code available for download.
Installation requirements/software: ArcGIS, .Net Framework 2.0, ArcGIS .Net support or MapWindow
Source/Link http://swat.tamii.edu/ (Last accessed August 14, 2018)
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B.23 SWMM5 (Storm Water Management Model)
Developer: Water Supply and Water Resources Division, EPA
Description: The EPA's SWMM is a dynamic stormwater runoff model that simulates runoff quantity
and quality in urban areas (Rossman, 2015). The model simulates runoff from a single rainfall event or
long-term (continuous) rainfall. Stormwater generated from subcatchments is then routed through a
network of pipes, channels, junctions, storage, treatment and control facilities. EPA's SWMM also has
the capability to evaluate effects of LID controls. SWMM simulates various hydrologic processes that
produce runoff, including time-varying rainfall, evaporation, snow accumulation and melt, rainfall
interception, infiltration, percolation, interflow, and nonlinear reservoir routing of overland flow. SWMM
contains a set of hydraulic modeling capabilities to handle networks of unlimited size and production of
pollutant loads associated with stormwater runoff. SWMM also provides an integrated environment for
running hydrologic, hydraulic, and water quality simulations, and viewing results in color-coded maps,
time series graphs and tables, profile plots, and statistical frequency analyses.
Versions: SWMM 5, previous version: SWMM 4
Features: Hydrology and hydraulics, pollutant loads associated with stormwater runoff. Hydrologic
processes: rainfall, snow, interception, infiltration, percolation, interflow, reservoir routing, runoff
reduction via LID controls. Hydraulic features: drainage networks, kinetic wave or full dynamic wave
flow routing methods. Pollutant loads features: dry weather pollutant buildup, pollutant washoff, street-
cleaning, BMPs.
Original Application: Urban (and suburban)
Mathematical method for flow routing and water quality: Runoff: water balance; Infiltration:
Horton's method, Modified Horton method, Green-Ampt method, Modified Green-Ampt method, SCS
curve number method; Flow Routing: steady flow routing, kinematic wave routing, or dynamic wave
routing; Water Quality: pollutant build-up is simulated using a power function, an exponential function, a
saturation function, or an external time series. Washoff of pollutants is simulated using an exponential
function, rating curve, or an EMC approach.
Input Data Requirements: Rainfall data, subcatchment data: assigned rain gauge, outlet node, land use,
imperviousness, slope, manning's n, depression storage, groundwater parameters, storm drain pipe
network information; invert elevation, depth to ground surface; inputs for outfall, storage units, flow
dividers, conduits, orifice, pumps, LID control information, pollutant characteristics (washoff
coefficients)
Data assembly requirements during and after emergency response: High
Outputs: Subcatchment variables (e.g., rainfall, runoff), node variables (e.g., water depth, hydraulic
head), link variables (e.g., flow rate, water depth, velocity), system-wide input variables (e.g., air
temperature, evaporation, total rainfall, snow depth)
Representation of Uncertainty: Although no uncertainty module is provided, uncertainty can be
propagated through SWMM using distributions of input variables and external analysis.
Hardware computing requirements: Designed to run under all versions of the Microsoft Windows PC
operating systems
Code language: C
Public/proprietary and Cost: Public, free
Prevalence: High. (SWMM has been used in thousands of studies worldwide)
Ease of use for public utilities: Moderate
Ease of obtaining information and availability of technical support: Information on EPA website. No
formal support offered. An active SWMM user's listserv was created by University of Guelph. Questions
on the model can be sent to EPA contact.
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Source code availability: Yes
Installation requirements/software: None
Source/Link: https://www.epa.gov/water-research/storm-water-management-model-swmm
(Last accessed August 14, 2018)
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B.24 WARM F (Watershed Analysis Risk Management Framework)
Developer: Electric Power Research Institute (EPRI), currently supported by Systech Water Resources
Description: WARMF, a decision support system designed to inform watershed analysis and TMDL
calculations (Herr et al. 2001), simulates watersheds as a network of linked land catchments, river
segments, and lakes. WARMF uses meteorological data to dynamically simulate runoff and nonpoint
source loads from land. The model predicts daily hydrology and water quality of rivers and lakes. The
model uses spatial information from a DEM file, land use and soils data, and displays spatial distributions
of point and nonpoint loading using GIS map format. WARMF contains five modules: an engineering
module to simulate the hydrology and water quality for the landscape of a river basin, a consensus module
to guide stakeholders to a consensus on a watershed management plan, a data module for editing the input
data, a knowledge module that includes reservoir operation rules, water quality standards, rate
coefficients, and a TMDL module for TMDL calculation.
Versions: v6.2
Features: WARMF contains a graphic user interface for various analyses including displaying spatial
information of the watershed, editing model inputs, model simulation, and TMDL calculation. The model
predicts daily flow and many water quality variables including pH, temperature, dissolved oxygen (DO),
ammonia, nitrate, phosphate, suspended sediment, bacteria, cations, anion, algal species, periphyton, and
metals such as iron, zinc, manganese, and copper. For stratified lakes, WARMF provides two options: ID
(vertically stratified) and 2D (using CE-QUAL-W2).
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff: mass balance of precipitation,
interception, evapotranspiration, infiltration, and percolation; Infiltration: modeled as a function of the
available water in the layer (difference between soil moisture and field capacity) and accounts for
exfiltration based on Darcy's Law; Flow Routing: unknown; Water Quality: pollutant buildup and
washoff calculations are adapted from SWMM code, sediment erosion from ANSWERS model code and
the universal soil loss equation. Algorithms in the model also account for water quality changes due to
atmospheric chemistry of tree canopy interception and through fall, snow chemistry, pollutant transport
with sediments, organic matter decay, fertilization, septic systems, biological and chemical reactions in
soils and water bodies.
Input Data Requirements: Spatial data: DEM, stream network, soil, land use, septic systems, and point
sources. Flow and water quality data for calibration. Coefficient data for physical data, meteorology
(snow, evaporation), land use, land application, irrigation, sediment transport, BMPs, septic systems,
chemical and biological reactions of pollutants, soil layers, mining, and CE-QUAL-W2.
Data assembly requirements during and after emergency response: Moderate
Outputs: Flow and water quality, pollutant loads.
Representation of Uncertainty: Stochastic simulation based on uncertainty in inputs is possible, using a
stochastic simulation tool
Hardware computing requirements: None.
Code language: Visual C++, Fortran
Public/proprietary and Cost: Public Domain, Free upon request
Prevalence: Moderate
Ease of use for public utilities: Moderate
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Ease of obtaining information and availability of technical support: Technical support available from
Systech Water Resources.
Source code availability: Not available in entirety (Fortran code available for review upon request)
Installation requirements/software: None
Source/Link: http://wqt.epri.com/watershed-model.html (Last accessed August 14. 2018)
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B.25 WinSLAMM (Source Loading and Management Model)
Developer: PV and Associates, LLC
Description: WinSLAMM, the Source Loading and Management Model, is a tool that relates sources of
pollutants to runoff quality in urban stormwater runoff (PV and Associates, 2014). The model is useful in
identifying pollutant sources and evaluating effectiveness of control practices and management strategies.
WinSLAMM calculates pollutant loads and runoff from different land uses and rainfalls and was designed
to provide relatively simple outputs such as pollutant mass and control measure effects for a large variety
of potential conditions. One unique feature of WinSLAMM is that it represents each land use from each
source area separately and does not lump all land uses together for one subcatchment or lump all the areas
for a single land use together. WinSLAMM is mostly used as a planning tool. The model focuses mainly
on smaller rainfall events and particulate runoff. It represents many stormwater controls and is based on
field data, therefore incurring minimum reliance on theoretical processes.
Versions: vlO.3.4
Features: Runoff and pollutant transport. The model considers six land uses: commercial, freeway,
industrial, institutional, other urban, and residential. Each land use is further defined by source areas:
roofs, sidewalks/walks, other impervious areas, pave parking/storage, street, freeway lanes/shoulders,
unpaved parking/storage, undeveloped areas, large turf areas, playgrounds, small landscaped areas, large
landscaped areas, driveways. Control devices: biofiltration, catch basins, cisterns, filter strips, grass
swales, green roofs, hydrodynamic devices, media filters, other control devices, porous pavements, street
cleaning, wet detention ponds. WinSLAMM generates stormwater data at the outfall to a catchment only
and does not route through a pipe network or combine hydographs or pollutant loads from multiple
watersheds. Currently, storm sewer and overland flow options are not available in the model.
Original Application: Urban
Mathematical method for flow routing and water quality: Runoff/Infiltration: SCS curve number
method and hydrographs; Flow Routing: Not applicable; Water Quality: Particulate solids loading (lbs) =
runoff volume (ft3) *particulate solids concentration (mg/L) * unit conversion
Input Data Requirements: Rain data, pollutant probability distribution, runoff coefficient, particulate
solids concentration, particulate residue reduction, street delivery parameters, particle size distribution
Data assembly requirements during and after emergency response: Low
Outputs: Runoff volume, particulate solids, pollutant, junction and outfall output, output from control
practices: runoff volume, particulate solids
Representation of Uncertainty: WinSLAMM uses stochastic analysis procedures to represent
uncertainty in model input parameters, to better predict the actual outfall conditions. Probability
information for the concentrations found in different source areas was used to predict probability
distributions of the concentrations.
Hardware computing requirements: Compatible with Windows XP, Vista, and 7 (limited testing on
Windows 8 and 10). Processor - 32-bit or 64-bit; Hard Drive Minimum 120 MB. No minimum RAM
requirements.
Code language: Visual Basic for Applications (VBA)
Public/proprietary and Cost: Private, $375 site license (free upgrade within one year), not annually
recurring.
Prevalence: Moderate. Approved in stormwater design manuals in Delaware, Georgia, Minnesota, New
York, Wisconsin and by different government agencies.
Ease of use for public utilities: Moderate
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Ease of obtaining information and availability of technical support: Product information available
online. Technical guidance not provided. Limited email support on how to model various applications.
Source code availability: Source code is not distributed, but algorithms are described
Installation requirements/software: Microsoft Access, ArcGIS
Source/Link: http://winslamm.com/ (Last accessed August 14. 2018)
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B.26 XPSWMM
Developer: XP Solutions (acquired by Innovyze)
Description: XPSWMM is a comprehensive software package for modeling of stormwater systems,
sanitary or combined sewer systems, and river systems (XP Solutions, 2014). XPSWMM is based on the
EPA SWMM5 model. The model can be used for single event or continuous rainfall-runoff simulation.
The model combines ID modeling of channels and pipes with a 2D surface grid for flood modeling and
mapping. XPSWMM is a link-node and spatially distributed model that can be used for analysis and
design of stormwater and wastewater systems. The model can be used in floodplain mapping and hazard
maps, culvert and bridge analysis, sanitary and combined sewer systems, and stormwater management
analysis. The model simulates buildup and washoff of pollutants from the watershed, pollutant and
sediment transport, as well as impacts of BMPs and LIDs. XPSWMM is integrated with GIS and CAD.
Versions: Version 2018, 19.1, previous version: version 2017, 18.1
Features: Includes all the features of EPA SWMM4 and some features of SWMM5 as well as offering
GIS and CAD integration. XPSWMM has several modules that expand the XPSWMM package,
including XP2D for 2D modeling, multiple domain (reduces cell numbers in 2D modeling), XPVIEWER,
real time control, and XPWSPG (Water Surface Profile Gradient). The model offers several bundle
options including the Stormwater and River modeling bundle options.
Original Application: Urban (and suburban)
Mathematical method for flow routing and water quality: Runoff: water balance/SCS curve number
method and a number of hydrograph methods including NRCS, Clark, Snyder, Santa Barbara;
Infiltration: Horton's method, Modified Horton method, Green-Ampt method, Modified Green-Ampt
method, and SCS curve number method; Flow Routing: steady flow routing, kinematic wave routing, or
dynamic wave routing; Water Quality: pollutant build-up is simulated using a power function, an
exponential function, a saturation function, or an external time series. Washoff of pollutants is simulated
using an exponential function, rating curve, or an event mean concentration approach.
Input Data Requirements: Like EPA SWMM (B. 1) but also requires a DEM and boundary layer
information for 2D modeling extension
Data assembly requirements during and after emergency response: High
Outputs: Subcatchment variables (e.g., rainfall, runoff), node variables (e.g., water depth, hydraulic
head), link variables (e.g., flow rate, water depth), system-wide variables (e.g., air temperature,
evaporation, total rainfall, snow depth), complete model data, computational details and results,
profile/cross section plots, flood mapping. Compatible with GIS files, CAD files, EPA SWMM files
Representation of Uncertainty: None. Uncertainty can be modeled by running multiple model scenarios
Hardware computing requirements: Minimum Pentium processor, 512 MB RAM, Windows XP, 7 or
8, 8.1, or 10- 32- or 64-bit, 50 GB hard disk, display 1024 x 768 24-bit color, 64 MB RAM.
Code language: Fortran and C++
Public/proprietary and Cost: Proprietary, estimated to be $5,000-$25,000 from online sources
Prevalence: High
Ease of use for public utilities: Advanced.
Ease of obtaining information and availability of technical support: Product information available
online. Technical support offered through "InfoCare" support portal from Innovyze Inc.
Source code availability: None. Only SWMM engine part is available.
Installation requirements/software: None
Source/Link: http://www.innovvzc.com/products/xpswmm/ (Last accessed August 14. 2018)
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