EPA-600/5-78-006b
April 1978
Socioeconomic Environmental Studies Series
A DEMONSTRATION OF AREAWIDE WATER
RESOURCES PLANNING • USERS MANUAL
Office of Air, Land, and Water Use
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the SOCIOECONOMIC ENVIRONMENTAL
STUDIES series. This series includes research on environmental management,
economic analysis, ecological impacts, comprehensive planning and fore-
casting, and analysis methodologies. Included are tools for determining varying
impacts of alternative policies; analyses of environmental planning techniques
at the regional, state, and local levels; and approaches to measuring environ-
mental quality perceptions, as well as analysis of ecological and economic im-
pacts of environmental protection measures. Such topics as urban form, industrial
mix, growth policies, control, and organizational structure are discussed in terms
of optimal environmental performance. These interdisciplinary studies and sys-
tems analyses are presented in forms varying from quantitative relational analyses
to management and policy-oriented reports.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/5-78-006b
April 1978
A DEMONSTRATION OF AREAWIDE
WATER RESOURCES PLANNING - USERS MANUAL
Contract No. 68-01-3704
Project Officer
Harry C. Torno
Office of Air, Land and Water Use
U.S. Environmental Protection Agency
Washington, D.C. 20460
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
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DISCLAIMER
This report has been reviewed by the Office of Research and Development, U.S. Environmental
Protection Agency, and approved for publication. Approval does not signify that the contents
necessarily reflect the views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or recommendation for
use.
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FOREWORD
This report documents a demonstration of areawide water resources
planning by the Metropolitan Washington, D.C. Council of Governments
(MWCOG). The study was initiated prior to the current 208 program,
and although the purposes and approaches are similar to a typical 208
project, the results should not be viewed as a prototype for the water
quality analytical methods, evaluative procedures, scope and level of
detail expected by the U.S. Environmental Protection Agency (EPA) in
certifiable 208 plan reports. Certain agencies many find that some or
all of the techniques described are applicable to their local situation,
but many others will have neither staff nor data, time and financial
resources to utilize the spectrum of tools described.
Publication by EPA does not indorse MWCOG techniques, nor does it
imply that utilization of these detailed techniques are requisite to
preparation of an adequate 208 plan. EPA has, for instance, recently
published an Areawide Assessment Procedures Manual (EPA Report
500/9-76-014, July 1976) which describes a much simpler set of
techniques which may be more relevant in areas where the systems are
neither so Large nor complex as these in Washington,, D.C.
xix
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ABSTRACT
The Metropolitan Washington Council of Governments Framework Water Resources Planning
Model is a comprehensive analytical tool for use in areawide water resources management
planning. The physical simulation portion was formed by linking component computer models
which test alternative future community development patterns by small area, estimate water
demands by usage categories, calculate sewage flows based on water demands and add
infiltration/inflow, simulate storrowater runoff, test application of alternative waste treatment
management systems, and simulate the quality response of the region's major water body.
The Users Manual describes the function and operation of each component model, alternative
models that could have been used, and elements of post computational analyses described. The
Users Manual is intended to be used in conjunction with other references which are cited.
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CONTENTS
Disclaimer ii
Foreword iii
Abstract iv
Figures vi
Tables vii
Acknowledgments viii
Introduction 1
Description of the Framework Model Chain 2
Utility of the Model and Post Computational Analysis 7
Description of Model Components
EMPIRIC* 16
INTERFACE4 21
MAIN H* 36
FIXSEWER 58
MUNWATRE 66
SEWAGE 73
EMPDA 83
PRESTORM f 89
STORMWATER MODEL* 99
SPLIT 103
TREATMENT Ill
POTOMAC ESTUARY MODEL* 120
References 151
Appendices
A. Alternate Models for the Community
Development Component 154
B. EMPDA File Formats 165
C. Estuary Hydrodynamic
Model Equations and Constants 172
D. Potomac Estaury Model Equations
and Constants 179
*Prirsary documentation for these models is found in referenced documents.
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FIGURES
Number Page
1 Framework Model Structure .............. 3
2 Program Function Flowchart for INTERFACE4 25
3 Sample Setup for XNTERFACE4 ........ .. •>. 26
4 Input - Output Flowchart for INTERFACE4 28
5 MAIN H Output Data .. 45
6 Program Function Flowchart for FIX SEWER .................. 60
7 Input-Output Flowchart for FIXSEWER .. 61
8 Program Function Flowchart for MUNWATRE 69
9 Input-Output Flowchart for MUNWATRE .. . 70
10 Program Function Flowchart for SEWAGE .., 77
11 Input-Output Flowchart for SEWAGE ... 78
12 Program Function Flowchart for EMPDA ................... 85
13 Input-Output Flowchart for EMPDA ... 86
14 Program Function Flowchart for PRESTORM 92
15 PRESTORM Subroutine Linkage ... 93
16 Input-Output Flowchart for PRESTORM 94
17 Program Function Flowchart for SPLIT 106
18 Input-Output Flowchart for SPLIT ............ . 107
19 Program Function Flowchart for TREATMENT 114
20 Input-Output Flowchart for TREATMENT 115
21 Potomac Estuary Model Segments 121
22 Potomac Estuary Model Operations 123
23 Water Quality Model Basis for Computations 145
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TABLES
Number
Page
1 Comparison of Water Consumption Rates. ............ 10
2 EMPIRIC Variables Input to MAIN H. . 35
3 MAIN II Parameters and Variables................. 46
4 Examples of Output From MAIN n................ 52
5 Format of FIXSEWER Output. ................ 65
6 Sample MUNWATRE Report. ..................... 71
1 Points in the Potomac Estuary, .................. 125
8 Location of Watershed Discharge Points
in the Potomac Estuary. 126
B-l EMPDA File Format............................. 165
B-2 EMPIRIC Model Output File Format............... 169
Vll
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ACKNOWLEDGMENTS
The authors would like to acknowledge the assistance of two other staff members of the
Metropolitan Washington Council of Governments who contributed to this report. Dr.
Magne Wathne, Environmental Engineer in the Department of Water Resources was
responsible for both the MAIN n and Potomac Estuary Model chapters and Ms. Judith
Blackistone, Research Assistant in the Office of Data Services assisted in several of the
detailed program descriptions.
Vlll
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INTRODUCTION
This Handbook documents the models used within the Framework
Model chain. Of the thirteen models used within the chain, four
are readily available to others. The EMPIRIC model used in
projecting community growth patterns, the MAIN II water demand
model, the Stormwater Management Model, and the Potomac Estuary
Model are all generally available. The other models which connect
these have been written by the staff of the Metropolitan Washington
Council of Government. The description of the models used in the
planning process is contained in Part A of this report, and in
"Framework Water Resources Planning Model - Technical Summary",
previously published by the Council of Governments. Reference to
those documents in conjunction with this Handbook is essential.
This chain of models was developed over a number of years to
facilitate water resources planning in the Washington Metropolitan
area. It has played a major role in both water supply and waste
treatment planning prior to the inauguration of Areawide Waste
Treatment Management Planning under 208.
ix
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DESCRIPTION OF THE FRAMEWORK MODEL CHAIN
The Framework Water Resources Planning Model (Framework Model) is
a planning tool for estimating and evaluating the effect of alternative public
policies on the major components of the urban water resources system.
Exercised as a complete unit, the Framework Model can simulate the
quality response of the area's major water body to alternative future land
use development policies, different wastewater treatment processes and
points of discharge and the quality response of the Potomac Estuary. The
Framework Model is actually a series of linked models that are illustrated in
Figure 1.
The Framework Model can be used to simulate the Estuary response to
facilities or activities which divert, augment, or contaminate the Potomac
River before it enters the region or flows into the Estuary. The construction
of power plants and water supply intakes will reduce river flow while the
construction of reservoirs could increase normal river flows. Uncontrolled
agricultural activity or the expansion of urban development with its
attendant runoff could degrade river water quality and decrease the
allowable waste discharges within the region.
The above discussion highlights how the Framework Model can be
exercised in different ways to satisfy urban water resource planning needs.
The simulations of the water resource system with the Framework Model
started with the output of the Community Development Component. While
several runs with different planning assumptions were made, the model run
number 6.2, modified by local government planning agencies, was selected
for a variety of planning functions within the region. Alternative 6.2
Modified formed the basis for the Framework Model runs described in this
report.
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Extract Input Data SPLIT
and TREATMENT Reports
FIGURE 1. FRAMEWORK MODEL STRUCTURE
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The model chosen for use in the Community Development Component
and described here, is the EMPIRIC Activity Allocation Model. It distributes
forecasted population and employment into Policy Analysis Districts (PADS)
from which projections useful in many planning programs can be drawn.
Different geographic areas of importance to air quality planning, transporta-
tion planning, as well as water resources planning are extracted from the
projections of the Community Development Component. Alternate models
that might be used in the community development component appear in
Appendix A.
For the purposes of water resources planning, the forecasts were
aggregated into 50 planning units that could be allocated to watersheds,
water services areas, and sewage service areas. Water demand was then
estimated for these planning areas by day, maximum day and peak hour and
category of use| residential and commercial, industrial demand by employ-
ment category and public and unaccounted uses. The planning areas were
aggregated to water service areas to summarize future water demand for a
specific utility. Water demand estimates were translated directly into
uninfiltrated residential and commercial sewage flow by the Sewage
Generation Component. Infiltration was calculated exogenously based on
the amount of developed land estimated by the Community Development
Component. The estimates needed for projecting the hydraulic loads sewage
from each district will impose on treatment plants.
Both the uninfiltrated residential and commercial sewage flows were
multiplied by user-specified pollutant concentrations allowing the program
to be tailored to local industrial conditions to provide estimates of total
sewage pollutant load by parameter.
The Community Development Component,, the source of population and
growth forecasts used in projecting sanitary waste generation, is also used to
project storm water runoff.
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From a data file, in "PRESTORM" EMPIRIC outputs of population and
employment for each pad are assigned to watersheds in proportion to the fractions
of area. This interface program also adds the input of the user's choice of storm to
be simulated. The dry period preceding a storm is used to calculate the pollutant
accumulation eligible for washoff, and the succeeding dry period is calculated to
show the time possible flow retention and stormwater treatment devices may be
permitted to operate at a constant rate to treat the surge of stormwater.
The simulation of a storm is completed by the EPA Stormwater Management
Model and the resultant runoff summarized by a program called "Split" which
divides that portion of the runoff flow and load that will be discharged directly in
the estuary, from that which will be simulated as treated in the Waste Treatment
Management Component.
The stormwater flows can be similated as treated in the Waste Treatment
Management Component by removing a user-specified portion of the pollutant
loads. The stormwater flows are then combined with simulated flows of sewage
when they are discharged into the estuary.
The Waste Treatment Management Component aggregates sewage flows and
loads into user-specified sewage service areas, and applies a user-specified removal
efficiency to each pollutant to simulate the application of technology such as an
advanced waste treatment. Flow to treatment plants due to stormwater runoff
through combined sewer systems can also be simulated.
The effluent from the Waste Treatment Management Component and the
additional stormwater flows and loads via the natural drainage system from the
Stormwater Runoff Component are input via the Pre-estuary model to the Estuary
Hydrodynainic Subprogram of the Receiving Water Component to project water
quality.
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Output from the Hydrodynamic Subprogram is used directly by the
Estuary Quality Subprogram which calculates the dissolved oxygen level for
each segment of the estuary over an entire tidal cycle. Output from the
Estuary Quality Subprogram consists of estimates of various parameters for
selected intervals of the 24-hour total cycle, usually one of the two-hour
periods.
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UTILITY OF THE FRAMEWORK MODEL
AND POST COMPUTATIONAL ANALYSIS
The previous uses of the Framework Model are described in the first
chapter of the "FRAMEWORK Water Resources Planning Model Technical
Summary" previously published by COG. The uses noted there include:
Simulations for environmental impact statements
Regional water demand projections
Analysis of water conservation measures
Estimating combined sewer overflow impacts
Sewage Flow Estimates
Non-point source impacts of urbanizing watersheds tributary to
water supplies
Other uses to which the Framework Model and post computational
analyses might be put in the regional planning process are discussed in more
detail below. Special references are made to the provisions of PL 92-500,
the Federal Water Pollution Control Act Amendments of 1972 (referred to
as the "Act" and by specific section). It should be stressed that many of the
uses of the Framework Water Resources Planning Model in the regional
planning process show that each component or element of this model can be
used independently or they can be linked, as was done in the full Framework
Model.
Identifying Future Development Patterns
The Framework Model physical simulations begin with the Community
Development Component, which, for metropolitan Washington, includes as
the basic computation tool the EMPIRIC Activity Allocation Model.
C.S. Spooner, et alv Technical Summary of the Framework Water
Resources Planning Model (Washington, B.C.: Metropolitan Washington
Council of Governments, 1974), p. 3.
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EMPIRIC is designed to distribute regional "control totals" of future households
and employment among a set of small sub-areas based on alternative public policies
and market forces. It is important to note that the Framework Model does not
provide forecasts of the control totals, but only distributions of these totals. The
forecasted regional growth, heavily driven by employment trends, migration rates
and family size is one of the many initial data items required for the model. The
Community Development Component distributes expected growth to small areas as
the first step in the Framework analysis. Subsequent estimates of water needs,
sewage generation and treatment, and non-point source generation can yield
assessments of the water resource impacts of the development patterns repre-
sented by the small area distributions. Alternate development patterns can be
simulated using the model by rerunning the component with different land use
assumptions, different statements of accessability to transportation, or perhaps,
by prohibiting growth in certain areas. Another process of testing patterns of
community development patterns could involve overriding the Community Develop-
ment Component output in both INTERFACE4 and PRESTORM (by producing a new
population, households, and employment by watershed) to produce future small area
projections reflecting different types of growth, different intensities of growth
(density of development such as apartments or single family homes or different
floor-area ratios) and different timing of growth.
Regional Analysis of Wastewater Treatment Efficiencies
Differences in wastewater treatment efficiencies can be easily tested by the
Framework Model. The model does not suggest which efficiency ranges are
realistic or affordable, but it does not provide a method of analyzing alternate
discharge points, alternate discharge quantities, the effects of the discharge given
different assumed river flows including flows diminished by water demands. The
model can also analyze the effects of the discharge given adherence to abatement
schedules for other sources of pollution in the estuary.
8
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Regional Analysis of Non-Point Source Controls
Non-point source contributions of pollution can be estimated using the
Stormwater Management Model (SWMM) through the Framework Model.
Essentially all the advantages or disadvantages of the use of SWMM, or a
substitute for it, in the storm-water runoff component would apply to
Framework. Because the SWMM and its alternates are undergoing constant
change, the most current literature citing their comparisons should be
consulted.
The importance of these models, when applied in the Framework Model
chain, is that the assumptions concerning community development used to
drive them is consistent with those used to project related impacts on water
supply and wastewater generation. A water quality management technique
is directly measured by exercising the Stormwater Component of the
Framework Model to estimate future runoff, and then by simulating
alternative control strategies such as Stormwater storage or treatment in
the Waste Treatment Management Component. Additional models, not now
part of FRAMEWORK, may be needed to estimate contributions from soil
erosion and stream channel enlargement.
Regional Analysis of Water Demand Reduction Systems
The Water Demand Component of the Framework Model identifies
various categories and subcategories of water use. These can be further
analyzed in two ways through post computational analyses. The first
technique is to establish a better understanding of average uses within major
subcategories such as domestic in-house use. This has been done in the
Metropolitan Washington area where plumbing fixtures in the home have
been assigned further allotments of domestic in-house use.
A comparison of \vater consumption rates in currently used fixtures
and the new consumption rates recommended in the amended sections of
plumbing codes provides some concept of the potential water conserving
effects of those amendments. Such a comparison is shown in Table 1. The
consumption figures shown for existing fixtures are the lower figures of the
consumption range for the respective fixture and can be considered to be as
much as three to five gallons in many instances.
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TABLE 1
COMPARISON OF WATER CONSUMPTION RATES2
Low Estimates For Specified By New
Fixture Existing Fixtures Amendments
Water Closets 5 gals./flush 3-K gals./flush
Urinals 4 gals./flush 3 gals./flush
Shower Heads 4 gals./minute 3 gals./minute
Faucets 4-% gals./minute 4 gals./minute
While Table 1 applies to fixtures in proper operating condition, it does
support the assumption of overall conservation factor of about 20 percent.
This 20 percent figure is further supported by the Washington Suburban
Sanitary Commission's Report on the Cabin John Drainage Basin Program
which listed reductions in water consumption ranging from 12 percent to 30
percent with the majority in the 20 percent to 25 percent range. In addition,
the more conservative figure of 20 percent allows several percentage points
lee-way to account for the vagaries of human behavior.
The effect of savings in this component of the regional water demand
becomes substantial when applied to total future water demand projections.
Using residential demand figures and limiting the projections to residential
use, analyses have shown that the projected increased demand for the year
1992 can be reduced by between 19 and 25 MGB, assuming that the
increased demand is met in newly built residential construction where
revised codes will be enforced,
The second form of post computational analysis involves the analysis
of water billing records to determine whether there are users of signifi-
cantly more water than projected by the model. Such uses may be singled
out for more detailed analysis of opportunities for demand reduction or some
form of recycling.
™_
ser£a_tion (Washington, D.C.; Metropolitan Washington CouncifoT
(Tovernments,. 1973)
10
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Evaluating Waste Load Allocations
An important requirement under Section 303(e) of the Act is the
establishment of pollutant load allocations within the major water bodies of
a region. This is normally done by starting with previous decisions on
control technology, or assessments of maximum pollutant loads allowable
within water quality standards. The estuary model, which serves as the
Receiving Water Component of the Framework Model, was developed for
what became the U.S. Environmental Protection Agency in 1969 and used to
establish effluent limits whicb are the basis for the current expansion and
upgrading of treatment plants discharging to the upper Potomac Estuary.
This estuary model has been revised and improved by MWCOG for use in the
Framework Model, and could be exercised to evaluate other load allocation
schemes to meet the Section 303(e) requirements. The Section 208 planning
guidelines identify the testing of alternative waste load allocations as a
major activity within the planning process as well. In doing this, the model
can be used for both point source loads and non-point source loads and can
evaluate the influence of water supply withdrawals on natural flow
conditions used to estimate maximum allowable loads,
Evaluating Cost-Effective Alternatives
The Framework Model does not contain cost estimating submodels, but
it does present a. method for distinguishing between alternatives on the basis
of cost effectiveness.
Section 212(2) of the Act provides that Federal construction grants can
only be made for systems which are determined by the U.S., Environmental
Protection Agency to be "cost-efficient" as defined by EPA cost-effec-
•3
tiveness guidelines.J The EPA guidelines indicate that:
The most cost-effective alternative shall be the
waste treatment management system determined
from the analysis to have the lowest present worth
and/or equivalent annual value without overriding
adverse non-monetary costs and to realize at. least
identical minimum benefits in terms of applicable
Federal, State, and local standards for effluent
quality, water quality,, water reuse, and/or lamd and
subsurface disposal.
11
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In the Framework Model the benefits are measured in terms of water
quality above standards. This approach seems appropriate to 208 Areawide
planning in areas where segments of waterways have been designated "water
quality limited." This designation applies to areas in which the application
of best practical waste treatment technology to point sources alone will not
assure water quality within standards. It is in these areas that nonpoint
source controls must be considered along with more advanced forms of
wastewater treatment and non-structural measures. The models contained
within the Framework Model chain offer a mechanism to compare treatment
techniques from the perspective of water quality. The "capability" of the
group of treatment techniques in an areawide water resources management
strategy has been defined as the extent of a constituent concentration of
less than or equal to a stated constituent concentration (the standard) for
~ 4
greater than or equal to a stated duration.
The measured extent selected for investigation is the length of estuary
affected in kilometers because it represents a barrier to the movement of
aquatic life and serves as a measure of the potential aesthetic effects from
degraded water quality. A 96-hour duration was chosen so that the
"capability" of each alternative could be compared if desired with 96-hour
median tolerance limit data for both aquatic species and the associated
species in their food chain.
Probability of Occurrence of SimuIa.t_ed_Ct>nditiQns
To perform a simulation using the Framework Model, assumptions must
be made concerning such conditions as the expected Potomac River flow
entering the region,, the expected storm flow, the expected water demand
withdrawals, the expected community development pattern, the reliability
of treatment works to perform as simulated, and other conditions.
Charles S. Spooner, John Promise, and Philip H. Gordon, A Demon-
gtrationjof^Areawide Water Resources^P3.anning (Washington, D»c7s ~
Metropolitan Washington Council of Governments, 1974), p. 144.
12
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The product of each of these event probabilities, if one assumes the
events are independent, is the joint probability of occurrence of all of these
events during the same time period.
The Framework Model contains a single event stormwater model that
makes the determination of joint probabilities necessary. The alternative to
single event models, continuous simulation models, allow the joint probabili-
ty of these complicated, and realistically interrelated events to be
determined empirically, Such flexibility adds a significant dimension to the
model chain as a planning tool and, the absence of this feature is a
significant drawback to the model chain in its present state.
Comparison of "Effectiveness" of Areawide Strategies
The product of the "joint probability of occurrence" and the "capa-
bility" is the expected "effectiveness" of an areawide water resources
management strategy. This can be expressed as:
Effectiveness = P(O) x C
Where P(O) is "joint annual probability of occurence" of conditions upon which
the simulation was based. The value "C", is the "capability" of the areawide
water resources management strategy, a measure of how well the strategy
might work under the conditions modeled.
Thus, the term "effectiveness" becomes a composite of the extent,
duration, constituent concentration, and joint annual probability of occur-
rence of the receiving water's response to alternative water resources
management strategies.
Of particular significance is that the expected "effectiveness" term
provides a link between bioassay results used to evaluate the toxicity of
selected chemical constituents of physical parameters to aquatic species
which are expressed as a 96-hour-mediajj-tolerance limit, TLm or TL^^.
This link is important because it relates the alternative water resources
management strategies to their effects on shellfish, fish, and wildlife which
are required to be protected by the Federal Water Pollution Control Act
Amendments of 1972.
13
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Cost Estimating
Local governments and their engineering consultants have extensive
experience in estimating and comparing the direct costs of proposed capital
facilities using methods long known to engineering economics and specified
in Federal Cost-effectiveness analysis guidelines. ' Direct costs consist of
both capital construction costs and annual costs for operation, maintenance,
and repair, with the latter divided between fixed annual costs and costs
which would be dependent on the annual quantity of wastewater processed.
The cost of an alternative water resources management strategy is
computed by discounting its costs over the selected planning period to
"present worth values" or the "average annual equivalent values." Alterna-
tive systems are then compared by ranking the estimated present worth
values, or used to identify where estimated values are identical within the
accuracy of the analysis. The approach is relatively straightforward once
the appropriate interest rate and planning period are selected, although
there may be a need to give special treatment to elements of operating
costs that are projected to inflate in cost at a rate well above any inflation
experienced by the rest of the economy. This can be done by discounting
them in present worth analysis at a rate less than that chosen for other
items of cost. The cost of chemicals, fuels, or power may qualify for such
treatment in present value analysis.
The total planning period capital cost element requires the following
information: the total capital cost at a stated cost index, the length of the
cosntruction period, and the life of the capital structure.
Operation and maintenance costs are divided into a fixed and variable
portion with the variable portion further divided into a base component and
a growth component. Thus the elements of operation and maintenance cost
are a fixed element, a variable-base element, and a variable-growth
element. The total planning period fixed operations and maintenance cost
element requires an estimate of the fixed annual operations and mainte-
nance cost at the end of the planning period, and is therefore based on the
design capacity at the end of the planning period.
14
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The total planning period variable operations and maintenance cost
element requires an estimate of the annual variable operations and
maintenance costs. These are based on the amount of growth in used
capacity of each device during the planning period and on the above-
mentioned variable operations and maintenance cost per unit capacity for
each device evaluated at the midpoint of the planning period.
Most water quality management alternatives chosen in the past have
been capital-intensive, thus lending themselves to straightforward engi-
neering economic analysis. As more comprehensive water resource
management strategies are considered., it will be accessary to consider such
things as flow reduction devices and use of pricing to reduce water
consumption. These programs do not fit easily into conventional cost
analyses. Therefore, the framework must be designed to permit calculation
and comparison of the costs associated with these alternatives as well.
Cost Effectiveness Determination
The cost-effectiveness of a strategy is a statement of both its costs
and effectiveness as defined above. Comparisons between strategies using
4
simple graphs of these quantities have been shown.
15
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DESCRIPTION OF MODEL COMPONENTS
THE 'EMPIRIC' ACTIVITY ALLOCATION MODEL
Purgose
^EMPIRIC" is one of a family of regional planning models, which are
referred to generically as "activity-allocation" formulations. It is designed
to perform three major functions:
To allocate regionwide projections of future population, employ-
ment and land use growth between a set of smaller subregions or
districts, based upon exogenously specified regional planning
policies;
To estimate the probable impact of alternative planning policy
decisions on the future distribution of regional growth; and
To provide an analytical foundation for the evaluation and
coordination of planning-policy decisions in a variety of different
functional areas.
Program Description
The EMPIRIC model was developed for COG by a consultant and is
documented in detailed reports resulting from his work. The model is
broken down structurally into four major components which are the
simultaneous equation module, the land consumption module, other
submodels, and the forecasting module.
The first module consists of a set of simultaneous, linear equations
relating projected changes over time in the subregional distribution of
population and employment one to the other, to their original distribution in
some base-year, and to the effects of selected planning policies imple-
mented over a given growth interval. The outputs of these equations are
typically expressed as estimates of the future numbers of households within
each subregion, broken down by income-level and type, together with
equivalent estimates of future employment by place-of-work, broken down
by industry type or land use classification.
5Peat, Marwick, Mitchell, and Co., "E_MPjRICVActivity Allocation
to the Washington Metropolitan Region (Washington,
^
D,C,: Metropolitan Washington Council of Governments, 1972)
16
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These initial population and employment projections are translated
into equivalent changes in land use for each subregion via a second "land-
consumption" module. This model accepts as input the outputs of the
simultaneous-equation model, together with the existing distribution of land
uses in each subregion in the given base-year and a range of permissible
future development densities. It generates as output updated estimates of
land use acreages, broken down by type, within each sub region.
A third module, consisting of a set of supplementary submodels and
also accepting as input the outputs of the simultaneous equation model,
operates in parallel with the land-consumption model. These submodels are
designed both to break down the initial set of subregional populations
projections into their equivalent, component distributions of population by
age, household size or number of workers/household, etc., and also to yield
estimates of supplementary employment levels for employment categories
not included in the simultaneous equation model. These typically include a
number of marginal employment classes, representing only small proportions
of total regional employment, such as "Construction" or "Mining".
These three components are calibrated in parallel using subregional
"activity (i.e., population and employment) and land use data collected for
two points in time, the COG application used inventories spaced eight years
apart, together with parallel data on the planning policies implemented
during the same time period. Typical policy inputs which may be
incorporated within the calibration process include regional transportation
and utility-system improvements; zoning, development and open-space
controls; environmental and conservation standards; or regional housing and
employment location policies.
They are then linked together with a fourth "forecast-monitoring"
module into a single forecasting chain, designed to yield recursive estimates
of the future subregional distribution of activity and land use for years into
the future, with the forecast for each year building on that for the preceding
year. Within this chain, each forecast is designed to be conditional both
17
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upon a presumed "regional total" of population and employment for the
region as a whole, and also upon the pursuit of a particular mix of future
regional planning policies over the forecast intervaL In order to use the
model for forecasting the analyst must, therefore, specify in advance the
projected levels of region-wide population and employment growth for each
forecast year, and also identify one or more "scenarios" of projected future
planning policies for use as input to the forecasting process.
Operationally, such scenarios are constructed in two parts. For those
policy measures incorporated as "direct variables" within one of the
calibrated modules, the analyst must simply specify the future value of the
variable for each subregion and each forecast year. This process, clearly, is
necessarily "limited to those policies which exerted a significant influence on
the pattern of growth over the calibration period. All other policies must be
treated somewhat differently, as "indirect constraints upon the forecasting
process."
Such constraints are invoked in part through the land consumption
module and in part via the set of forecast-monitoring routines outlined
above. In concert, they permit the analyst to constrain the initial set of
forecasts-by pre-specifying minimum or maximum levels of activity in any
subregion, specifying proportional mixes of activity types or restricting
particular areas of land to specific types or densities of development.
In its simplest mode of operation,, the model may be used to generate
one single chain of forecasts based on one single policy scenario.
Alternatively, by varying the mix of policy inputs for particular forecast
years or particular subregions - i. e.s by creating a set of alternative
scenarios - it may be used to test the probable impact of alternative policy
mixes on the future pattern of regional growth.
A typical set of model outputs is summarized on the following pages,.
18
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of:
Output Available from Community Development Component (EMPIRIC)
For each Policy Analysis District and each Forecast Year Eastimates
Family Households In Low Income Quartile
Family Households in Low-Middle Income Quartile
Family Households in Upper-Middle Income Quartile
Family Households in Upper Income Quartile
Unrelated Individual Households
Employment in Manufacturing, Transportation, Communication and
Utilities
Employment in Retail and Wholesale
Employment in Financial, Insurance, Real Estate and Services
Employment in Government
Employment in Aricultrue and Construction
POPULATION by Age
Under 5 years
5-14
15 - 19
20- 29
30- 49
50- 64
65 and Over
HOUSEHOLDS by Size
1 Person
2 Persons
3 Persons
4 Persons
5 or more Persons
HOUSEHOLDS by:
Single-Family Households
Multi-Family Households
LAND USE by Type
Residential
Industrial
Commercial
Intensive Institutional
Extensive Institutional
Parks and Open Space
Vacant
Residential (incl. Streets)
EMPLOYMENT by LAND USE
Residential Land
Commercial Land
Institutional Land
Agricultural and Vacant Land
19
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EMPIRIC Availability
The EMPIRIC model was developed by, and is available from Peat,
Marwick, Mitchell & Co., 1025 Connecticut Avenue, N.W., Washington, B.C.,
Z0036. Information on its application to the Metropolitan Washington Area
can be obtained from the Metropolitan Washington Council of Governments,
1225 Connecticut Avenue, N.W., Washington, B.C. 20036.
20
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MTERFACE4
PURPOSE
The purpose of the INTERFACE4 program is to j&in the model which
predicts community development alternatives with the model which predicts
water demand. Because over 5000 data elements are required to operate the
Water Demand Component for each combination of development plan and
forecast year, A computer program (INTERFACE4) was developed to
manage this data. Appropriate EMPIRIC output from the Community
Development Component is aggregated into planning units f and then into
water service areas, and reformated for direct input to MAIN EL, the Water
Deraand Component.
INTERFACE4 selects appropriate EMPIRIC output data, aggregates
EMPIRIC and constant data into matrix format by water .service areas, and
arranges data into the format required by the MAIN H nuodel. INTERFACE4
produces MAIN IE input both in printed and computer readable form, and
prints an optional matrix (ZMAIN) that can be altered and used again as
input to INTERFACE4 in preparation for subsequent MAIN II runs. This
optional ZMAIN MATRIX FILE enables the user to maintain complete MAIN
n input data sets from each modified run of the INTERFACE4 program,
which might result from considering different development alternatives or
different forecast years in the EMPIRIC Model, without having to duplicate
large card decks.
CHARACTERISTICS OF OPERATION
Language IBM FORTRAN IV (G Level)
Region Program size is 190K. Actual region size at time of
execution is dependent on the number of input data sets and their associated
block sizes. Size required for documented runs was 275K.
21
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PROGRAM DESCRIPTION
The user, through a series of program control cards, can modify the
values of the MAIN H input data set and select the input and output for each
of the INTERFACE4 programs. The two sources of input data for the
INTERFACE4 program are the EMPIRIC File, as modified by the I4EMP
subroutine of INTERFACE4, and the ZMAIN MATRIX FILE, which is the
output from a previous INTERFACE4 run. The user, through a series of
cards, is able to select the input data required for each run.
The control card stream, is read and verified for proper order and
processed as follows: The first card in the stream, which must be the TITLE
CARD is read and printed. The next card, CARD TYPE #1, specifies the type
of input (EMPIRIC or ZMAIM MATRIX FILE, created from a previous
INTERFACE4 run), and a FORTRAN unit number for the Jocation of the
selected file, and the number of planning units to be used in the run. If the
CARD TYPE #1 specifies the ZMAIN MATRIX FILE as input, the file is read
into the ZMAIN MATRIX, area of the program. The program then searches
for and reads all optional TYPE #Z cards. These cards, if present, enable the
user to insert new values directly into the ZMAIN MATRIX with constant
data not found in the EMPIRIC data. When this task is completed the
program will read a TYPE #3, which will call the subroutine I4EMP in to
modify the EMPIRIC DATA. The CARD TYPE #3 contains the FORTRAN
unit number of the EMPIRIC file to be used and the total number of Area
Allocation Cards that are to follow in the Program.
the following functions are performed by the I4EMP subroutine:
21
-------
1. Reads and prints the Card Type #3A, Area Allocations Cards,
and stores the data in tables. These cards enable the user to
convert the Empiric Policy Analysis Districts to various area
systems schemes. A percentage of each PAD is then allocated to
the new system, in this case a (water service area) planning unit.
2. Reads and prints the two Card Type #3B, Sewer Coeffi-
cient/Quartile Index Cards, and stores the values in a table. The
coefficients are multiplied by one of the income quartiles of
households, selected by the corresponding quartile index, to yield
the number of households by value range for metered water and
flat rate water service.
3. Reads and prints the two Card Type #3C, Index Variable Cards.
These cards equate the 16 data categories needed for the
computation of the MAIN n input to the corresponding data
categories in the EMPIRIC file for the desired forecast year.
4. Reads the EMPIRIC File, selects the proper variables by the
Index Variables Cards and accumulates the variables by planning
unit through the use of the area allocation cards. When the
EMPIRIC file has been processed the computations are then
performed for the MAIN n Data. Households, by seven home
value ranges for both metered and flat rate water, are computed
using the coefficients and quartile index table. Persons per
household, households per residential acre, number of employees
by five major employment categories, total population and
population by two age groups are stored in the ZMAIN MATRIX.
Control is returned to the main program when these tasks are
completed by the I4EMP subroutine.
The program reads the control card stream and searches for the
optional CARD TYPE #4. This card, if present, enables the user to override
the MAIN n Data elements that were computed from the EMPIRIC data and
insert user selected values into the ZMAIN MATRIX. CARD TYPES #2 and
#4 are used to modify specific cells in the ZMAIN MATRIX. The matrix
contains a Panning Unit number, which can vary from 1 to 200, as one
dimension and the MAIN Et data variable number, which refers to one of the
105 MAIN n parameters, as the second dimension.
The next card, CARD TYPE #5, provides the user with three different
output options.
23
-------
1. Print the MAIN H input data set. This option lists the values in
the ZMAIN MATRIX in the card format that is required by the
MAIN n program.
' 2. Transfer the MAIN II input data set, A computer readable
storage device. The MAIN II file is written to a storage device,
either tape or disk, to be used as direct input to the MAIN n
program.
3. Write the ZMAIN MATRIX data set. The ZMAIN MATRIX is the
alternate input to INTERFACED This matrix can be updated
using CARD TYPE #2 and #4 to produce a new MAIN H input set
at a significant savings in computer time.
After all the output operations have been performed the final card in
the control card stream should be a CARD TYPE #9. A normal end of job
message will be printed and the run will then terminate. The job will
terminate at any point in the program if the program encounters any errors
or unidentified card types in the control card stream.
SAMPLE SETUP - See Input-Output Flow Chart.
24
-------
MAIN PROGRAM
YES
CARD TYPE 01
COL. 5 = '2'
SUBROUTINE 'I4EMP'
FIGURE 2. INTERFACE 4 PROGRAM FUNCTION FID&OIART
25
-------
CARD TYPE #4
OPTIONAL
1 ONLY
1 FOR EACH
OUTPUT SELECTED
AS MANY AS REQUIRED
FOR DATA MODIFICATION
CARD TYPE #9
2 ONLY
2 ONLY
AS MANY AS REQUIRED
FOR AREA ALLOCATION
1 ONLY
AS MANY AS REQUIRED
FOR DATA MODIFICATION
1 ONLY
1 ONLY
CARD TYPE #4
OPTIONAL
CARD TYPE #2
OPTIONAL
1 ONLY
1 FOR EACH OUT-
PUT SELECTED
AS MANY AS RE-
QUIRED FOR DATA
MODIFICATION
AS MANY AS REQUIRED
FOR DATA MODIFICATION
1 ONLY
1 ONLY
INPUT OPTION #1
PROCESS AN EMPIRIC DATA SET
INPUT OPTION #2:
PROCESS AN EXISTING
INTERFACE4 ZMAIN MATRIX
DATA SET
FIGURE 3. SAMPLE SETUP FOR INTERFACE4
26
-------
DATA SPECIFICATIONS
Input Description
Input to the INTERFACE4 program is a computer generated input data
file and a manually coded series of user control cards. One of two computer
generated inputs to INTERFACE4 are:
1. EMPIRIC Data Set.
A data record for each EMPIRIC Policy Analysis District, is
generated by the EMPIRIC Activity Allocation Model described
previously. The EMPIRIC data set must be used initially, but as the
program is rerun in considering different management alternatives and
different forecast years, the second input format, the ZMAIN
MATRIX, is more useful.
2. ZMAIN MATRIX FILE
This is the optional output of a previously run INTERFACE4
program. This file contains one record for each planning unit,, which
contains all the data needed to construct MAIN n input for that
planning unit.
The control cards needed for the program operation have no default
values associated with any of the parameters. Unless otherwise noted, all
parameters are required for proper execution of the program. The control
cards for the program operation must be in the following order;
CARD #1
Types Title Card
Number: One card only
Purpose; Specify run title
Format: (20A4)
27
-------
CARD TYPE #9
END OF JOB
CARD TYPE #5
[OUTPUT OPTIONS. 3)
USER
CONTROL
CARDS
CARD TYPE #4
OVERRIDE DATA
FOR ZMAIN
MATRIX < #3C
I
FROM PREVIOUS
INTERFACE4 RUNS
INPUT
I OPTION 2
INPUT OPTION 1
(INCLUDES 3A, B,
AND C CARDS)
OUTPUT OPTION 1
INTERFACE4
OUTPUT OPTION 3
PRINTOUT OF
VALUES IN
ZMAIN MATRIX
OUTPUT
OPTION 2a
/ZMAIN MATRIX/
/ AS DIRECT
1 INPUT TO
\ MAIN II
OUTPUT
OPTION 2b
I
(•'DATA MAY BE MOD]
IFIED BEFORE
AUTOMATING AS IN-
PUT INTO MAIN Hi
NOTE: Dashed lines show
alternative inputs
and outputs.
FIGURE 4. INTERFACE4 INPUT-OUTPUT FLOWCHART
28
-------
CARD #2
Type:
Number:
Purpose:
Format:
Card Type #1
One card only
Specify input data set, unit number of data set, if ZMAIN
MATRIX FILE is selected for input, and number of planning
units for the run.
(I1,1X,3(I3,1X),F10.0,ZX),Z(I3,1X),F10.0)
CoL
1
2-4
5
6-7
8-9
23-25
26-80
'I1 card type entered
Blank
T - EMPIRIC Data set selected as input.
Blank
Unit number of ZMAIN MATRIX FILE use when Col.
5 = '2'.
Number of planning units for the run.
Blank
CARD #3
Type:
Number:
Purpose:
Format:
Card Type #2
As many as needed to insert user supplied data, (optional card)
To enter constant MAIN E values into the ZMAIN MATRIX.
Constant data would be items such as year, values ranges,
and other MAIN n values that are not computed from
the EMPIRIC data.
(I1,1X,3(2(I3,1X),F10.0,2X),2(I3,1X),F10.0)
Col. 1 '2' card type entered
2 Blank
3-5 Planning unit number
6 Blank
7-9 MAIN n data element number
10 Blank
11-20 Value to be inserted in ZMAIN MATRIX
21-22 Blank
23-25 Planning unit number (value #2)
26 Blank
27-29 MAIN H data element number (value #2)
30 Blank
29
-------
31-40 Value to be inserted in ZMAIN MATRIX
41-42 Blank
43-45 Planning unit number (value #3)
46 Blank
47-49 MAIN II data element number (value #3)
50 Blank
51-60 Value to be inserted in ZMAIN MATRIX
61-62 Blank
63-65 Planning unit number (value #4)
66 Blank
67-69 MAIN n data element number (value #4)
70 Blank
71-80 Value to be inserted in ZMAIN MATRIX
As many of these cards as needed for modification can be inserted into the program.
CARD #4
Type;
Number:
Purpose;
Format:
CARD #5
Type:
Number:
Purpose:
Format;
Card Type f-3
One only - must be present if CARD TYPE #1 Col. 5 -
T
Specify the unit number of the EMPIRIC data set and
the number of Area Allocation Cards that follow*
(I1,1X,3(I3,F10.0,ZX),2(I3,1X),F10.0)
Col.
2
3-5
6
7-9
'3' card type entered
Blank
Unit number of EMPIRIC data set
Blank
Number of CARD TYPE 3A's Area
Allocation Cards, that follow
CARD #3A Area Allocation Cards
The number of cards in this section must equal the
value coded in Col. 7-9 of CARD TYPE #3. The
program allows a maximum of 200 allocations
To distribute a certain percentage of each Policy
Analysis District to a planning unit.
(9X,3tt3,lX,I3,lX,F7.0,5X),llX)
Col. 1-9 Blank
10-12 Planning unit number
30
-------
CARD #6
Type:
Number:
Purpose:
Format:
CARD #7
Type:
Number:
Purpose:
Format:
CARD #3B Meter-Flat Sewer Coefficients/Quartile Index Card
Two must be present if Card Type #3 is present
The seven coefficents are multiplied by the number
of households by income quartiles to yield households
by home value range. The quartile index number
is used to select the proper household quartile for
each of the seven operations.
(7F10.0,7I1,3X) First card for Meter Water, Second
card for Flat Water.
Col. 1-10 Coefficient for value range #1
11-20 Coefficient for value range #2
21-30 Coefficient for value range #3
31-40 Coefficient for value range #4
41-50 Coefficient for value range #5
51-60 Coefficient for value range #6
61-70 Coefficient for value range #7
71 Quartile index for value range #1
72 Quartile index for value range #2
73 Quartile index for value range #3
74 Quartile index for value range #4
75 Quartile index for value range #5
76 Quartile index for value range #6
77 Quartile index for value range #7
78-80 Blank
CARD #3C Index Variable Cards
Two must be present if Card Type #3 is present
To equate the 16 items used in the computation
of the MAIN II values to the corresponding items
on the EMPIRIC data set,
16(2X,I3) Eight, pairs per card for the two cards
required.
Col. 1-2 Blank
3-5 Index number, refers to information
in the EMPIRIC data set.
6-7 Blank
8-10 EMPIRIC variable number for four years,
1968, 1976? 1984, 1992.
11-12 Blank
13-la Index number
31
-------
16-17 Blank
18-20 EMPIRIC variable number
21-22 Blank
23-25 Index number
26-27 Blank
28-30 EMPIRIC variable number
311-32 Blank
33-35 Index number
36-37 Blank
38-40 EMPIRIC variable number
41-42 Blank
43-45 Index number
46-47 Blank
48-50 EMPIRIC variable number
51-52 Blank
53-55 Index number
56-57 Blank
58-60 EMPIRIC variable number
61-62 Blank
63-65 Index number
66-67 Blank
68-70 EMPIRIC variable number
71-72 Blank
73-75 Index number
76-77 Blank
78-80 EMPIRIC variable number
CARD #8
Type:
Number:
Purpose:
Format:
Card Type #4
As many as needed to insert user supplied data, (optional card)
To insert data into ZMAIN MATRIX after the data
from the EMPIRIC FILE has been modified by the
I4EMP subroutine. This card will supply data to
override the data items in the MATRIX, and inserted
into the ZMAIN MATRIX.
(I1,1X,3(2I3S1X),F10,0,2X),2(I3,1X)F10.0)
Col. 1 '4' card type entered
2 Blank
3-5 Planning unit number
32
-------
6 Blank
7-9 MAIN n data element number
10 Blank
11-20 Value to be inserted in ZMAIN MATRIX
21-22 Blank
23-25 Planning unit number (value #2)
26 Blank
27-29 MAIN n data element number (value #2)
30 Blank
31-40 Value to be inserted in ZMAIN MATRIX
41-42 Blank
43-45 Planning unit number (value #3)
46 Blank
47-49 MAIN E data element number (value #3)
50 Blank
51-60 Value to be inserted in ZMAIN MATRIX
61-62 Blank
63-65 Planning unit number (value #4)
66 Blank
67-69 MAIN E data element number (value #4)
70 Blank
71-80 Value to be inserted in ZMAIN MATRIX
CARD #9
Type:
Number:
Purpose:
Format:
Card Type #5
As many as needed
Select the types of output
Same as Card #4
Col. 1 = 5 (Card Type)
Col. 3-5 = 1-Print MAIN E Input File in Card Format
2-Write MAIN E Input File to Storage
Device - Input to MAIN n
3-Write ZMAIN MATRIX to storage device -
Input to INTERFACE4
Col. 8-9 = Unit Number of Output Data set if Col. 3-5 = 2 or 3
33
-------
Type: Card Type #9
Number: 1 only
Purpose: Signify end of control cards
Format: Col. 1 = 9 (Card Type)
Output Description
1. The MAIN n Data set can be printed and/or wirtten to a storage Device
2. The ZMAIN MATRIX, a file of all the values in the MAM H Data
set, can be written to a storage device and then used as input to subsequent
INTERFACE4 runs.
3. All control cards input to the program are printed, and diagnostic
messages are printed as necessary.
34
-------
VARIABLE
tCMBER
1
2
3
4
6
7
8
9
10
11
20
21
22
23
24
25
28
29
30
31
32
33
39
40
DAm ITEM
ft Families1 in Lower Inc. Quartile
# Families in Low/Middle Quartile
tt Families in Upper/Middle Quartile
ft Families in Upper Quartile
# Employees in Manu/T.C.U.
# Employees in Retail/Wh. Trade
ft Employees in F. I. R.E. /Services
fl Employees in Government
S Employees in Agriculture/Construe.
Acres of Residential Land
# HH of Size 1
£ HH of Size '*.
f* HH of Size 3
(f HK of Size 4
ft HH of Size 5
* HH of Size 6 & Over
Population 5 Years
Population 5-14 Years
Population 15 - 19 Years
Population 20 - 29 Years
Population 30 - 49 Years
Population 50 - 64 Years
P
ft of Single Family HH
* of Hulni Family HH
USAGE;
INTERMEDIATE
I
INTERMEDIATE
DIRECT
t
1
V
DIRECT
INTERMEDIATE
INTERMEDIATE '
A
INTERMEDIATE
DIRECT
DIRECT
INTERMEDIATE
A
^ /
INTERMEDIATE
ITEMP»EPA1(I)+EPA2(I)+EPA3(I)+EJ?A4,(I)
EPAP1«-EPA1 ( I) /ITEMP
EPAP2='EPA2 ( I } /ITEMP
EPAP 3=EPA3 ( I ) /ITEMP
EPAP4HEPA4 (I) /ITEMP
ZMAIN(I,97)°EPA6(I)
ZMAIN(I,98)-=EPA7(I)
ZMAIN(I,99)=EPA8(I)
2MAIN(I,100)=EPA9(I)
ZMAIN{I,101)=EPA10(I)
DENSHHH (IJ/EPA11 {1} ZMAIN (I, 32)*«DENS ZMAIN (1 ,59) eDENS ZMAIN (I , /y;BDEN5>
ZMAIN(I,14)'=DENS ZMAIN (I ,38)»DENS ZMAIN (I ,64) =DENS ZMAIN {1,84) =DENS
ZMAIN(I,20)=DENS ZMAIN (1 ,44)-DENS ZMAIN (1 ,69) "DENS ZMAIN'fl ,89)-=DENS
ZMAIN (1 , 26)C1DENS ZMAIN (I , SOJ^DENS ZMAIN (1/74) "DENS
PCN1>EPA20(I)*1.+EPA21{I)*2.+EPA22(I)*3.+EPA23'(I)M.+EPA24(J).*5.
HH(I)=EPA20(I)+EPA21(I)+EPA22(I)+EPA23(I)+EPA24(I)+EPA25(I.)
PEPL"PCNT/HH(I)
ZMAIN(I,60)=PEPL
ZMAIN(I,65)=PEPL
3MAIN(I,70)«PEPL
ZMAIN(I,75)=PEPL
ZMAIN(I,80)=PEPL
ZMAIN (I , 85) =PEPL
ZMAIN(I,90)=PEPL
POPU=EPA28{I)+EPA29(I)+EPA30(I)+EPA31(I)+EPA32(I)+EPA33(I)+
*EPA34(I)
ZMAIN(I,95)°EPA29(I)
ZMAIN ( 1 , 9G) =EPA30'(I )
QUART(1)°EPAP1*EPA39(I) ZMAIN (1 ,13)=C (l)>QOftRT (N (1) ) ZMAIN"(1 , 37) -=C (5) *QUART (N (5) )
QUART(2)«=EPAP2*EPA39(I) ZMAIN (1 , 19)°C (2) *QUART (N (2, ) ZMAIN (I,43)=C (6) *QUART(N (6) )
QUART(3)-EPAP3*EPA39(I) ZMAIN (I ,25) «C (3) *QUART (N (3) ) ZMAIN (I ,49}=C (7) *QUART(N{7) )
QUART(4)-=EPAP4*EPA39(I) ZMAIN (1 , 31)=C (4) *QUART (N (4) )
QUART(1)'=EPAF1*EPA40(I) ZMAIN (1 ,58) =C1 (1) *QUART (Nl (1) ) ZMAIN (1 ,78)=C1 (5) *QUART(Nl (5)
QUART(2)=>EPAP2*EPA40(I) ZMAIN (1 ,63}»C1 (2) *QUART (Nl {2} ) ZMAIN (I,83)=C1 (6) *QUART(N1 (6)
QUART(3)=EPAP3*EPA40(I) ZMAIN (I ,68}»C1(3) *QUART (Nl (3) ) ZMAIN (I,88)=C1 (7) *QUART(N1 (7)
QUART(4)=EPAP4*EPA40(I) ZMAIN (1 , 73)°C1 (4) *QUART (Nl (4) )
MAIN DATA
VARIABLES
6-CDAT
10-POPU
13-NUMB-l-M
14-DEHS-l-M
19-NOMB-2-M
20-DENS-2-M
25-NUMB-3-M
26-DENS-3r-M
31-NCJMB-4-M
32-DENS-4-M
37-NUMB-5-M
38-DENS-5-M'
43-NUHB— 6-M
44-DENS-6-M
49-NUMB-7-M
50-DENS-7-M
58-NUMB-l-F
60-PEPL-l-F
63-NUMB-2-F
64-DENS-2-F
65-PEPL'2-F
68-NUMB-3-F
69-DENS-3-F
70-PEP^3-F
73-NUHB-4-F
74-DENS-4-F
75-PEPL-4-F
78-NUMB-5-F
79-DENS-5-F
80-PEPL-5-F
83-NUMB-6-F
85-PEP3>6-F
88-NUMB-7-F
89-DENS-7-F
90-PEPL-7-:F
9S-SKLL
96-SKLH
9 7- C001
98-C002
99-C003
100-C004
101-C005
ITEMS
CONSTANTS.
1-MACH
2-LBIN
3-LIBY
4-PROJ
5-PNCH
7— LATD
S-LONG
9-CCBN
11-VALN-l-M
12-VALX-l-M
15-ANPR-l-M
16-SMPR-l-M
17-VALN-2-M
18-VALX-2-M
21-AHPR— 2— M
22-SMPR-2-M
23-VALS-3-M
24-VALX-3-M
27-ANPR-3-M
28-3MPR-3-M
29-VALN-4-M
30-VALX-4-M
33-ANPR-4-M
34-SMPR-4-M
35-VALN-4-M
36-VALX-5-M
39-ANPRT-5-M
4C-SMPR-5-M
41-VALN-6-M
42-VALX-6-M
45-ANPR-6-M
46-SMPR-6-M
47-VALN-7-M
48-V7ALX-7-M
51-ANPR-7-M
52-SMPR-7-M
53-LOWV -M
54-MEDV -M
55-HIGH — M
56-VALN-l-
57-VALX-l-
61-VALN-2-
62-VALX-2-
67-VALX-3-
71-VLAN-4-
72-VALX-4-
76-VAUJ-5-
77-VAIJC-5-
'81-VALN-6-
82-VALX-6-
86-VALN-7-
87-VALXT-7-
91-LOWV -
92-MEDN -
93-HIGH -F
94-HOSP
102-C006
103-C007
104-C008
105AIHP
TABLE 2. EMPIRIC VARIABLES INPUT TO MAIN II COMPUTATIONS
-------
MAIN H WATER DEMAND COMPONENT
PURPOSE
The MAIN H system is a tool for estimating and forecasting municipal
water requirements. The system itself is a set of formalized procedures
which have been developed specifically for use in planning municipal water
supply- The word MAIN is an acronym meaning Municipal And Industrial
Needs.
Water requirements can be estimated separately for the residential,
commercial/institutional, industrial, and public-unaccounted sectors of a
designated urban area. Within these sectors, requirements may be further
estimated for individual categories of water users, such as metered-sewered
residences, flat-rate sewered residences, commercial establishments, insti-
tutions, three-digit standard industrial classification (S.LC.) manufacturing
categories, etc. Estimates are made of mean annual, maximum day, and
peak hour requirements for each category.
To accomplish all of this, the MAIN H system is composed of a system
of modular computer programs which solve equations that define water
usage as a function of various dependent economic, social, and environmen-
tal parameters used as input data. These parameters include such items as:
number of residences, by home value range, population density, price of
water, sewage disposal method, number of students, number of hospital bedss
geographic location of the urban area, etc.
36
-------
The MAIN n system is based primarily on the research work performed
at The Johns Hopkins University.13' 14' In this work, detailed studies
were made of the factors that influence residential and commercial usage of
water. A number of equations were derived using regression analysis and
statistical techniques to relate water usage quantitatively to the factors or
parameters that have the greatest influence or usage. The work of other
organizations such as the Bureau of the Census and the American Water
Works Association was used to supplement the Johns Hopkins University
7 &
work. The MAIN n system itself was developed by Hittman Asrociates ' *
9, 10
In the context of FRAMEWORK, the water demand generated by MAIN
n is a prerequisite for finding the flows of municipal wastewater. The
output from MAIN n is therefore routed to a sewage generation routine
where it represents the input data. MAIN n has been applied separately in
several planning efforts, as tabulated by Hittman . These efforts have
shown MAIN n to be a flexible and comprehensive planning tool on its own.
CHARACTERISTICS OF OPERATION
Language: FORTRAN IV Level G
Region: Covers 200K during execution
PROGRAM DESCRIPTION
Model Calculations
Main n is structured as a series of subroutines which either manipulate
the data, make computations, or edit the output data. Following is a brief
description of each of these subroutines.
Control Program
Subroutine Name: MAIN Program
37
-------
MAIN is the control program for the water demand model system. It
controls the execution of the two input routines and calls into execution
each of the computational subroutines.
Municipal Data Input Processor
Subroutine Name: REDINP
The subroutine reads in municipal data, identifies it, and stores it in
the proper place in memory. Municipal data are composed of system
options, municipal identification, and parameters.
Library Data Input Processor
Subroutine Name: REDCOF
This routine reads the program's library data, identifies it, and stores
it. The Library contains the following industrial and climate-related data
that allows the program to be tailored to area of study:
Residential equations constants
Residential climatic factors as a function of latitude and
longtitude.
Commercial category names
Commercial Parameter names
A table of each of the commercial usage coefficients for mean
annual, maximum day and peak hour.
Industry category names
A table of each of the industrial usage coefficients for mean
annual, maximum day and peak hour (latter two not available for
COG region)
Public/unaccounted category names
A table of each of the public/unaccounted usage coefficients for
mean annual, maximum day and peak hour.
In this part of the subroutine, the latitude and longitude of the urban area
being analyzed are used as indices to locate the proper values of
"evapotranspiration" and "precipitation".
38
-------
Residential Usage Computational Program
Subroutine Name: RESDNT
This routine controls the calculation of residential water usage values
and determines which table of values is to be printed. The residential water
usage includes both domestic and sprinkling usage, mean annual, maximum
day, and peak hour usage, are found for metered sewer and flat rate sewer
areas.
The average rates of uses are found from the following set of
formulas, computed for any value range of house, or apartment, is
Domestic Use in Single-Family Households, Metered and Sewered
> ± (1)
2000
Sprinkling by Single-Family Households, Metered and Sewered Areas
omesc se n nge-amy ouseos, eere an e
Areas (gpd) = [~206 + 3.47/ VALNi + VALXi\ _1>3 ANPRj]
L ^ 2000 / -J
0.803
1.45
SMPR^
, c-,
ll57 / VALN- + VALX-; \
i - i ) NUMBi (2)
on / J 1
|~
L
where
E = summer evapotranspiration
P = summer precipitation
Domestic Use in Apartments, Flat Rate and Sewered Areas (gpd) =
28 9 + 4.39!^i_i+ 33.6 (PEPL^
" \ 2000
Sprinkling by Apartments, Flat Rate and Sewered Areas (gpd) =
0 5531 (4)
94.0 (0.083) ( i £j NUMB-L
V 2000 J
Formula (4) is due to Howe et al , while (1), (2), (3) are from Hittman .
Commercial Usage Computational Program
39
-------
Commercial Usage Computational Program
Subroutine Name: COMMER
This routine computes the current annual average water usage for each
type of commercial/institutional establishment and the total water usage for
the study area for each type of water demand - mean annual, maximum day
and peak hour.
Industrial Usage Computational Program
Subroutine Name: INDSTL
This routine calculates industrial water usage values - mean annual,
maximum day and peak hour usage.
Public/Unaccounted Usage Computational Program
Subroutine Name: PUBLIC
This routine controls the calculation and displaying of public/unac-
counted water usage values.
Commercial, industrial, and public/unaccounted usage are computed by
means of the same general formula for any category, k: Average daily use
gpd = COEF. PARA, (5)
3 K
where
COEF = usage coefficient
PARA = level of activity
according to Hittman
Residential Report Generator Program
Subroutine Name: RDSPLY
This routine controls the displaying of the residential water usage
values. Tables of residential water usage values can be printed for each of
the two residential categories; meter ed^sewered and flat rate sewered.
The tables give the range of home values, number of dwelling units,
the mean annual average usage and its distribution between sprinkling and
domestic usage; the maximum day and peak hour usage. The amounts of
summer evapotranspiration and summer precipitation are given for the study
area.
40
-------
Commercial Report Generator Program
Subroutine Name: CDSPLY
This routine controls the display of the commercial/institutional water
usage information.
Industrial Report Generator Program
Subroutine Name: IDSPLY
This routine controls the printing of the tables of industrial water
usage values for mean annual, maximum day and peak hour usage. Then a
breakdown of these three usage types by industrial code (S.I.C.) and industry
category is given.
Municipal Summary Report Generator Program
Subroutine Name: DISPLY
This routine prints a summary table of municipal water usage showing
mean annual, maximum day and peak hour for each land use category.
Ancillary Program
Subroutine name: INITL, UNPACK
The ancillary programs perform arithmetic operations and data
manipulations which are needed because of the structure and logic of MAIN
n. INITL creates artificial starting values of several matrices prior to the
computations. UNPACK interprets a single variable (NN) which actually
consists of three separate variables.
41
-------
Predicting Residential Water Usage
The principal factor influencing total annual water use in residential
area is the total number of homes. In addition to the number of households,
the John Hopkins study identified three other important factors which affect
water use in residential areas. These are the economic level of consumers
as indicated by the market value of their homes, the climate, and whether
customers are metered or billed on a flat-rate basis.
A 1971 study of water and sewage rates indicated that all customers
served by public water systems in the Metropolitan Washington region are
metered. However, since individual apartment units do not directly pay for
water on a per gallon basis, the MAIN II system assumes that apartment
dwellers will consume water at the same rate as flat-rate homeowners.
Thus, for the Framework Model, all owner-occupied single-family
homes and townhouses are considered to be in the metered category, while
all individual aparment units are considered to be in the flat-rate category.
Although of lesser significance, it should be noted that households served by
private systems such as wells are considered by the Framework Model to
consume water as though they were metered.
According to the researchers, whether consumers are metered or on a
flat-rate basis appears to have only minor influence on domestic (household)
use but considerable influence on sprinkling use. However, the original flat-
rate sprinkling equations in the MAIN n system were developed based on
dwellings in the midwest, not for apartments in the urban east. Therefore,
in the Framework Model flat-rate sprinkling equations have been modified to
correspond to the relationships found by Howe and Linaweaver in 1967 and
published in 1971 by Howe et al for the National Water Commission,12
42
-------
Another major factor influencing residential water demand is climate.
As with flat rate vs. metered residences, climate has little effect on
domestic use but a substantial effect on water used in sprinkling. The
hydrologic factors found to be most important are precipitation, runoff,
infiltration, root-zone storage, and evaporation. As part of the Main II
system, a Library of Water Usage Coefficients was designed to contain the
required climatic data for the entire United States. Therefore, the climatic
data contained in this library for Washington, D.C. have been utilized.
The other major factor influencing residential water demand is the
income level of the consumer. It appears that a consumer in a higher-valued
area is likely to have more water using appliances and more ornamental
plantings requiring sprinkling. For areas served by public sewer, the
regression analysis indicated a correlation between domestic use and
average market value of homes.
It was found that in areas with septic tanks for sewage disposal,
economic level has little effect on domestic use, but that population density
(persons per dwelling unit) accounted for almost all variations in domestic
use.
For use in the Framework Model, the metered-sewered residences have
been divided into seven value ranges (VALN and VALX for each range).
Actual 1970 Metropolitan Washington data of single family units by these
seven value ranges was first obtained in 1970 dollars. Since the MAIN n
system requires that home value be indicated in I960 dollars, the number of
households in each value range was adjusted accordingly.
In a similar fashion, the flat-rate-sewered apartment units were
divided into seven value ranges. However, since actual 1970 data was
available for the number of households by rent (and not by the equivalent
cost of the apartment unit if it were a single-family home), it was first
necessary to convert from rent value to equivalent home values. The
resulting value ranges were somewhat lower than those in the metered-
sewered category. The ranges of values for single family units was
developed from income distributions (quartiles). It was assumed that each
income range would be associated with a certain range in home values. The
43
-------
water demand could then be computed for each value range. The derived
distribution of home values was the one whose total water use was equal to
the recorded demand.
Because of the flat-rate vs. metered service and the septic tank vs.
sewers relationships, the MAIN It system includes submodels to estimate
residential water demand by four major groupings. These are metered
(water bill) and sewered, metered and septic tank, flat rate and sewered, and
flat rate and septic tank residences. However, since septic tank systems are
gradually vanishing in the Metropolitan Washington region,, the Framework
Model utilizes the first two categories only in estimating future water
demands.
Another factor that influences residential water use is the cost of
water. Indeed, further investigation by the Johns Hopkins researchers
necessitated the reworking of the original models of residential water
demand to include the influence of cost.
Predicting Commercial, Institutional and Industrial Water Usage
The MAIN II system permits the commercial,, institutional and
industrial segments of the community to be divided into categories by type
establishment o:t industry, and water demand to be estimated for each type.
Commercial establishments include businesses of all kinds, mostly retail,
which are not included in the Bureau of the Census Standard Industrial
Classifications. Because of the similarity of the MAIN II computational
techniques for the commercial, institutional and the industrial categories,,
the format of the data to be useds and the fact that there is little industry in
the Metropolitan Washington region, these two categories were combined
under the commercial and institutional heading.
44
-------
The MAIN H system has a built-in set of 23 genera! purpose
commercial and institutional categories. Some examples are hotels,
hospitals, restaurants, schools and theatres. For each category the values of
appropriate water use parameters are required. For hotels, the number of
square feet is required, for schools the number of students, and so forth.
The usage of coefficients for the commercial submodel were developed
in a study of commercial and institutional establishments by Wolf et all6
These values are stored in the library of water usage coefficients of the
MAIN n system. Therefore, the user is only required to provide the
appropriate value for each dependent parameter, such as a number of
elementary school students or square feet of hotel space.
In the COG version of MAIN II there are eight distinct commercial
categories of water users. Three of these are specified a priori and
incorporated in the system and the coefficient library. For the five user-
specified categories it was necessary to aggregate mean annual, maximum
day and peak hour usage coefficients. For this purpose^ each category was
divided into its smallest components based on the SIC code or other
available data. As an esample, Transportation/Communication/Utilities was
divided into 8 subcategories such as transportation by air, communication,
and local passenger transit. The eight categories and their definitions ate
listed in Table 2, on the fourth page.
Predicting Public-Unaccounted Water Usage
The public-unaccounted submodel computes water which is pumped
without subsequent recovery of revenue from a residential., commercial, or
industrial customer. ThisL usage is divided into the following three
categories: free service, losses (probably due to leakage), and usage by
airports. Computation is based on national average per-capita usage
coefficients.
45
-------
CHARACTERISTICS OF OPERATION
Input-Output Flowchart - The input-output flowchart and program listings
for the available MAIN n program are available in Appendix A of Reference
20, MAIN n System Users Manual, Volume 31.
Input Descriptions - The MAIN H input data as used in the Framework model
is shown in Figure 5.
The category required, "Municipal Data", consists of the following data
subgroups:
Municipal
Data Subgroup
OPTIONS
CITYDATA
METRSEWR
METRSEWR
FLATSEPT
Definition
Run and output options
Municipal identification data
Metered water bill and public
sewered residences
Metered water bill & septic
tank residences
Flat rate water bill & public
sewered residences
Used in this
Version
Yes
Yes
Yes
No-assume 100%
of population sewered
Yes
FLATSEPT
COMMPARM
INDPARAM
PUBPARAM
PUBANAVE
PUBMAXDY
PUBPEKHR
Flat rate water bill & septic
tank residences
Commercial/Institutional
Parameters
Industrial Param. (employment)
Public/Unaccounted parameters
Public/Un. arm. avg. water req.
Public/Un, max. day water req.
Public/Un. peak hr. water req.
No
Yes
No - (included in
COMMPARM instead
Yes
No-not needed
No-not needed
No-not needed six
using PUBPARAM
46
-------
'OPTIC
)NS'
'CITY
(user- supplied)
(1
to
5)
'CDAT'
(6)
LATD1
(7)
' LONG '
(8)
DATA'
1
|
'CCBN- ,popu,
(9) (10)
(Resident.
'METRSEWR1
(1
3t
value
range)
I YT
UjN
(11)
I
(2nd
value
(7
(Home values)
1
th
1
value
I
X3WV
1 1
'MEDV 'HIGH'
(53)
(54) (55)
range) range)
'POBPARAM'
! 1
'AIRP' 'LOSS' 'FSER'
(105) (Provided (Provided
internally) internally)
Lai data)
1
'FLATSEWR1 (Home values)
1
(1st (2nd (7th 'LOW
value value ' ' ' value (91)
range) range) range)
1 'M
EDV1 'I
UGH'
(92) (93)
same <61 to 65) same (86 to 90)
' 'VAX
,X' 'NU
Nffi
(12) (13)
'H0£
DE
US'
(14)
P'
(94)
'ANE
R' 'SME
(15)
'SKJ
jL'
(95)
R1
(16)
•SKI
Ji' 'COC
)1
(93) (97)
'VA1
LN' 'VALX' 'NUMB' 'DENS' 'PEPL'
(56) (57) (58) (59) (60)
'C002' 'C003' 'C0041 'COOS' 'C0(
36'
(98) (99) (100) (101) (102)
'COC
'COMM
)7' 'CO
PARM'
08'
(103) (104)
FIGURE 5. M7AIN II INPUT DATA - MUNICIPAL DATA
-------
As shown in Figure 5, each subgroup requires data for a number of
parameters: For example, the subgroup 'CITYDATA' requires values for
each combination of planning unit, development policy and forecast year for
the following five parameters: 'CDAT', 'LATD', 'LONG', 'CCBN', and
'POPU'. The number in parenthesis in the figure refers to the position of
each data element in the INTERFACE matrix ZMAIN.
Realizing that such data identification names need further explana-
tion, Table 3 has been provided. Included in this table is the name,
definition, and the unit of measurement of each parameter, as well as an
indication of the necessary level of detail. Of the 105 data elements
required for each planning unit, 65 are considered to remain constant for all
development plans and forecast years.
TABLE 3
MAIN n PARAMETERS AND VARIABLES
A. Run and Output Descriptions
Name of
Parameter
'MACH'
'LBIN'
'LIBY'
'PROJ'
'PNCH'
Definition
Computer ID number
Fortran input device
for Library
Option to print
for Library
Auxiliary storage
to do forecasting
Option to punch
deck of output
Units
N/A
,
N/A
N/A
N/A
N/A
Parameters Required
By 4
N/A
N/A
N/A
N/A
N/A
48
-------
Parameters and Variables in MAIN II
B. Municipal Identification Data
'CITYDATA' Subgroup
Name of
Parameters
'CDAT'
'LAID1
'LONG'
'CCBN'
'POPU'
Definition
Selected year for
analysis
Latitude of planning
unit
Longitude of planning
unit
Dept. of Commerce
National Composite
Construction Cost Index
to deflate home values
to I960 price level
Population
Units
Year
Whole
degrees
Whole
degrees
Index
People
Parameters Required
By
Planning unit
Planning unit
Planning unit
Metro region
Planning unit
Residential Data
Name of
Parameter Definition
Parameters Required
Units By
'METRSEWR' Subgroup
'NUMB'
'DENS'
'ANPR'
'SMPR1
'VALN'
'VALX1
'LOWV
Number of occupied
housing units
Housing density
housing units
Marginal price of
water (year round)
Summer price of
water
Lower limit of each
Upper limit of each
Number of value ranges
with median value
below $7500
I960 dollars
49
# each ?alue range*
units within planning unit
units/ planning unit
res. acre
-------
Table 3 (continued)
Parameters and Variables in MAIN II
'MEDV Number of value
ranges with median
value of at least
$7500 but less than
$15,000 1960 dollars
'HIGH' Number of value
ranges with median
value of at least
$15,000 I960 dollars
'FLATSEWR' Subgroup
'NUMB' (See METRSEWR)
'DENS' (See METRSEWR}
'PEPL' Population density
'VALN'
'VALX'
#
ranges
Planning unit
# ranges
Planning unit
persons per
housing unit
Planning unit
'LOWV
'MEDV
'HIGH1
(See METRSEWR)
D. Commercial/Institutional Data
'COMMPARM' Subgroup
Name of
Parameter
'HOSP'
'SKLL1
'SKLH'
C001
C002
C003
C004
Definition
Hospitals
School, Elementary
School , High.
Manuf acturing/Transp .
Communications 5
utilities employment
Retail/Wholesale
Trade employment
Finance , Insurance ,
Real Estate/Services
employment
Government employment
Units
Beds
student
student
people
employed
people
employed
people
employed
people
employed
Parameters Required
By
Planning unit
Planning unit
Planning unit
Planning unit
Planning unit
Planning unit
Planning unit
50
-------
Table 3 (continued)
Parameters and Variables in MAIN
C006
C007
C007
Not being used
Not being used
Not being used
E. Public/Unaccounted Data
'PUBPARAM' subgroup
Name of
Parameter
Definition
Units
Parameters Required
By
"MRP1
'POPU'
Water required by
airport to extent it
is provided from
municipal system
Determined under
'CITYDATA' Subgroup
avg. #
passengers
/day
Planning unit
(if it has airport)
Typical Outputs
Table 4 displays the output from a typical application of MAIN n. It
summarizes the average daily water use quantities as computed from
equations (1) through (5). Also included in the tables are the quantities
which represent maximum daily and peak hourly use.
MODEL AVAILABILITY
The Main n model, modified as described here, may be obtained from the
Metropolitan Washington Council of Governments, 1225 Connecticut
Avenue, N.W., Washington, D.C. 20036,
51
-------
MUNICIPAL WATER REQUIREMENTS FOR THE CITY OF PLANNING UNIT 2
FOR THE YEAR 1976 ANALYZED BY MAIN SYSTEM
CURRENT RESIDENTIAL WATER REQUIREMENTS BY CATEGORY
METERED AND SEWERED AREAS (A)
VALUE RANGE (?)
0.
5000.
10000.
15000.
20000.
25000.
35000.
- 4999.
- 9999.
- 14999.
- 19999.
- 24999.
- 34999.
- 40000.
TOTAL
NO. OF
UNITS
175.
1107.
4543
7911.
9211.
6105.
4421.
33473.
DOMESTIC SPRINKLING
19975.
145709.
676998.
1316054.
1692201.
1280531.
1042349.
6173816.
391.
12185.
104918.
297575.
498833.
501788.
502194.
1917882.
AVG. DAY
20366.
157894.
781916.
1613628.
2191033.
1782318.
1544542.
8091696.
MAX. DAY
25657.
245790.
1338066.
2890580.
4008858.
3287690.
2831443.
14628083.
PEAK HOUR
110112.
865390.
4216309.
8472480.
11162374.
8670464.
7187677.
40684784.
(C)
Explanatory Notes:
(A) Metered and Sewered Areas were assumed to be single family households — see text.
(B) Home Value Ranges.
(C) Expressed as daily consumption. True peak hour consumption equals one twenty fourth the
amount printed.
TABLE 4 EXAMPLE OF OUTPUT FROM MAIN II
-------
MUNICIPAL WATER REQUIREMENTS FOR THE CITY OF PLANNING UNIT 2
FOR THE YEAR 1976 ANALYZED BY MAIN SYSTEM
CURRENT RESIDENTIAL WATER REQUIREMENTS BY CATEGORY
FLAT RATE AND SEWERED AREAS (A)
VALUE RANGE ($)
0.
5000.
7500.
10000.
12500.
15000.
17500.
- 4999.
- 7499.
- 9999.
- 12499.
- 14999.
- 17499.
- 25000,
TOTAL
NO. OF
UNITS
431.
1378.
3101.
3704,
11700.
13624.
15569.
49508.
DOMESTIC SPRINKLING
53096.
192598.
467382.
598917.
2020088.
2501674.
3200707.
9034461.
0.
0.
0.
0.
0.
0.
0.
0.
AVG . DAY
53096.
192598.
467382.
598917.
2020088.
2501674.
3200707.
9034461.
MAX. DAY
53096.
192598.
467382.
598917.
2020088.
2501674.
3200707.
9034461.
PEAK HOUR(C)
250962.
848848.
1978560.
2445283.
7982418.
9596167.
11655927.
34758144.
Ul
Explanatory Notes:
(A) Flat Rate and Sewered areas were assumed to be apartments - see text.
(B) Apartment value range.
(C) Expressed as daily consumption. True peak hour consumption equals one twenty
fourth of the amount printed.
TABLE 4 EXAMPLE OF OUTPUT FROM MAIN II
•(Continued)
-------
MUNICIPAL WATER REQUIREMENTS FOR THE CITY OF PLANNING UNIT 2
FOR THE YEAR 1976 ANALYZED BY MAIN SYSTEM
CURRENT RESIDENTIAL WATER REQUIREMENTS IN GALLONS PER DAY
Average
Daily
17126144.
Maximum
Daily
23662528.
Peak
Hourly (A)
75442928.
REQUIREMENTS BY TYPE - DAILY AVERAGE
Type
(Single-Family) Metered and
Sewered Areas
(Apartment) Flat Rate and
Sewered Areas
TOTAL
No. of Units
33473,
49508.
82981.
Gallons Per Day
Domestic Sprinkling
6173816.
9034461.
15208277.
1917882.
0.
1917882.
Total
8091696.
9034461,
17126144.
Summer Evapotranspiration % Inches <# 16.00
Summer Precipitation % Inches< # 6.75
Max. Day Evapotranspiration % Inches< # 0.29
Explanatory Notes;
(A) Expressed as daily consumption.
TABLE 4 EXAMPLE OF OUTPUT FROM MAIN II
(Continued)
-------
MUNICIPAL WATER REQUIREMENTS FOR THE CITY OF PLANNING UNIT 2
FOR THE YEAR 1976 ANALYZED BY MAIN SYSTEM
TOTAL COMMERCIAL
-------
Ln
cr,
MUNICIPAL WATER REQUIREMENTS FOR THE CITY OF PLANNING UNIT 2
FOR THE YEAR 1976 ANALYZED BY MAIN SYSTEM
TOTAL PUBLIC-UNACCOUNTED REQUIREMENTS IN GALLONS PER DAY
Average Maximum Peak
Daily Daily Hourly (A)
4261963. 4261963. 4261963.
REQUIREMENTS BY TYPE OF PUBLIC-UNACCOUNTED USAGE IN GALLONS PER DAY
Average Maximum Peak
•pe Daily Daily Hourly
Distrib. Losses 3159366. 3159366. 3159366.
Free Services 1102597. 1102597. 1102597.
Explanatory Notes;
(A) Expressed as daily consumption.
TABLE 4 EXAMPLE OF OUTPUT FROM MAIN II
(continued)
-------
SUMMARY OF MUNICIPAL WATER REQUIREMENTS FOR CITY OF PLANNING UNIT 2
ESTIMATED WATER REQUIREMENTS FOR YEAR 1976
% ALL VALUES IN GALLONS PER DAY ^.
Municipal
Residential
Commercial
Industrial
Public and Unacc.
Average
Daily
29234160.
17126144.
7846069.
0.
4261963.
Maximum
Daily
35770544.
23662528.
12844744.
0.
4261963.
Peak
Hourly (A)
87550944.
75442928.
33959152.
0.
4261963.
Explanatory Note:
(A) Expressed as daily consumption
TABLE 4 EXAMPLE OF OUTPUT FROM MAIN II
(continued)
-------
FIX SEWER
PURPOSE
The purpose of the FIXSEWER program is to adapt the water demand
data output from the MAIN n program to the input specifications for the
SEWAGE and MUNWATRE programs. The MAIN n program generates a data
set for water demand by planning unit. A set of records for each planning
unit contains flat rate (apartment,) metered (single family,) commercial, and
public and unaccounted water demands. Each of these sets contain the
average, maximum, and peak hour demand and, for residential data, demand
by each of seven homes value ranges.
If a planning unit has no water demand data for a major category the
MAIN n program will not write that portion of the set. The SEWAGE
program must have a complete set of records for each planning unit. The
FIXSEWER program is needed to verify the order of the data fields from
MAIN H and insert dummy data for any fields that are missing. When
FIXSEWER encounters missing fields, it prints an output message indicating
which field is missing, inserts the key word for that field, a blank for the
data value, and flags the record with an identifier.
CHARACTERISTICS OF OPERATION
Language; ANSI COBOL
Region; Program will execute in a 32K region
PROGRAM DESCRIPTION
FIXSEWER's first program command opens all input and output files
and initializes work areas. The control card file is read and the program
continues. If an end of file is detected an error message is displayed on the
printer and the run is terminated.
58
-------
The first record of the input file, which is the MAIN n output file, is
read and the identity of each subset examined. The first subset, the flat
rate service demand data, is identified by 'FLTSEWUS1. If the subset read is
tagged with this identifier the program checks for identifying subset detail
and inserts blank data values into the subset before writing it into the
FIXSEWER output file. If the record has been modified by the program a
flag 'CG' is placed in columns 75 and 76 of the record. If the subset
identifier read by the program is not 'FLTSEWUS', an error message is
displayed and a dummy subset of 'FLTSEWUS1 records is created and written
into the FIXSEWER output file to complete it.
The user supplied input/output print option control card is checked
after each subset of the MAIN n dataset is read in and after each subset is
written to the FIXSEWER output dataset to determine if the records should
be printed.
This basic operation of checking for the proper subset identifier,
checking for missing subset detail, inserting blank data values, creating
dummy subset records when the subset identifier is missing, and checking
the control card for print options is also performed on all subsets. The
subsets must be in the order shown.
The process is repeated for each planning unit set until an end of file
signal is reached on the MAIN n file. The program then closes all input and
output files and displays count of total input records and total output
records.
SAMPLE SETUP - See input-output flow chart
59
-------
SUB-\ / \ \BEAD MAIN I
S-MISSIBX PROCESS1
ORDER KEY-
WORDS S DATA j
NSERT MISSIHC3
KEYWORDS
FIGUEE 6,. FIXSEWER PHDGRAM FUNCTION FLCWaiART
60
-------
FROM MAIN II
WATER DEMAND
MODEL
INPUT-OUTPUT
PRINT CONTROL
CARD
V
PIXSEWER
V
PRINTED
INPUT OUTPUT
CORRECTIONS
FIGURE 7. INPUT-OUTPUT FLCWCHART FOR FIXSEWER
61
-------
DATA SPECIFICATION
Input Description
Input to FIXSEWER is in the form of two files; a computer generated
data file and user control card.
The data file is the output from the MAIN n program and is assigned in
this program to DDNAME 'SYSO12'. This file contains the water demand
data (see below) for each planning unit.
A user-supplied control card must be present for the program to
execute. This card gives the user the option of printing the input and/or
output data from the program. The DDNAME of the Control Card File is
'SYSOll'.
The format of the card is:
Col. 1 = 'Y'
Col. 2 = 'Y
Col. 3-80 BLANKS
This indicates the input data is to be printed.
If this information is not needed, leave this
field blank.
This indicates the output data is to be printed.
If this information is not needed, leave this
field blank.
The MAIN n output data file consists of a set of water demand data
for each planning unit. A set consists of eight subsets. The subsets are:
Subset Identifier
'FLTSEWUS1
'METSEWUS'
'COMMAVEQ'
'COMMXQ'
'COMMPEKQ
'PUBLICAA'
'PUBLICMD'
'PURLICPH'
containing water use by
containing water use by
containing water use by
containing water use by
containing water use by
containing water use by
containing water use by
containing water use by
Data
flat rate apartments
Metered Single Family
Commercial (Average Daily)
Commercial (Maximum Daily)
Commercial (Peak Hour)
Public and Unaccounted
(Average Daily)
Public and Unaccounted
(Maximum Daily)
Public and Unaccounted
(Peak Hour)
62
-------
The subsets 'FLTSEWUS' and 'METSEWUS' contain component records identified by:
QDOM
QSAV
QSMX
QPEK
NUMB
This component record contains domestic usage in gallons
This component record contains sprinkling usage in gallons
This component record contains maximum daily usage in gallons
This component record contains peak hour usage in gallons
This component record contains number of households
The five keywords above are repeated for each of the seven home
value ranges from the MAIN n model.
Subsets 'COMMAVEQ', 'COMMAXQ' and 'COMPEKQ' contain component
records identifiably:
HOSP
SKLL
SKLH
This component record contains hospital usage in gallons
This component record contains elementary school usage in gallons
This component record contains high school usage in gallons
This component record contains industrial usage in gallons
Subsets 'PUBLICAA', 'PUBLICMD1, and 'PUBLJCPH' contain component
records identified by:
LOSS
FREE
AIRP
This component record contains distributed losses in gallons.
This component record contains free service usage in gallons
This component record contains airport usage in gallons
The last record of each subset contains only the component 'ENDD'.
SUBSET IDENTIFIER RECORD FORMAT
Column
1-1
2-9
10-10
11-14
15-72
73-74
75-78
79-80
Data
Blank
Subset identifier
Blank
Data Year
Blank
2 Character Subset Identifier
Data Year
Subset Card Sequence Number
63
-------
SUBSET RECORD FORMAT
Column Data
1-1 Blank
2-5 Keyword #1
6-18 Value #1
24-27 Keyword #2
28-40 Value #3
46-49 Keyword #3
50-62 Value #3
63-72 Blank
73-80 Same as subset identifier
record
Output Description
The FIXSEWER program writes one output file that contains the
corrected MAIN n output water demand data. The format and organization
of the data is the same as the MAIN H output. (See Table 5). The DDNAME
for this file is 'SYS008'. Descriptive messages are printed whenever a subset
or part of a subset is missing and has to be replaced by the program. The
DDNAME for the print file is 'SYS014'.
64
-------
cr>
ft
s
w
rn
1 "
2
E-j
§
,,
m
P
K
0
H
JH
£
W
w
m
M
>jj
Ej
H "
2
§
g W
ill
£ K
' ^_ Kl T'si- '"MS \')»v
SUBSET ID ' nnO'1 74.S'.
QPFK 1SO7S.
nnOM ;^*4 1 ? ,
0"f K 1 P4* 71.
fi n n y * S 0 q * .
QPF« ^q-jcjm^
COMPONENTS nnp'« «US*.
OPF^ 3ASf 7o .
oni'M 14,->?on.
oul- "• "iin^V?.
nnrv ] s VH(3 .
OHF< fr4fi'4^1.
nnn^^ ?o n T in .
OPFw 1 ]^qii^, 1 f
, i-Mnn
^ ^^___»^ ^'1- TSf Mi|S I'KV
SUBSET ID " Onnw M""1.
OPFK 3SQPO.
O'VW 1HQP7.
')'"'< ?11 7hn.
(V-.r>M 1 7'JS1n.
noF< ) iii ni .
COMPONENTS onn*i 7A1c-f,.
I)"F< | 77frOi;.
ono— cniMA'rv 1QQ?
HOC;"
C001 ^0'J4) .
COMPONENTS CPO(, ?S4M1.
C007
SUBSET ID *- POMMPF^O 199^>
H(1C;P
Cl'O) VJC,^-,,
COMPONENTS C004 7^9)1.
C007
V FMiin
^ SUBSET ID >- PMHl ICAA 1 4<5?
CnMpONENTS Lnct; ,^4,,,^.
FMOli
SUBSET ID *~ '>P|"I 'r"n I9r'-'
CCMPONENTS ^ns^ 1^9^,14.
K ^nn
SUBSET ID ^- Pili'LIfH 1 -Jl^
COMPONENTS in^t; 1<-')M'..
V "'•"I"
nSAV 741. OSMX P'71 .
^JMl'l^ '•')7.
MUM" 1 a/, .
OriAV ll!f,44. 0^'>R.
»IIIWM rtOi.
0<;A\/ SSU01. O^''^ ^1340.
'IIIMJ 1 \?i1.
TSAV 71 . 0^'^X 1710.
Mil/in 44.
OSA» ?^'^"'. OV1X 10119.
NilM'l />77.
OSA7 MH'. ns"l» 19H949.
MI.IMM 1117.
OSAV ?>7''S4. ns'-iX ?40Hh4.
NIIMH inn*,.
n^AV 'ill'ilo. nt;. 34?':'?7.
M'IM'l 704.
SKI.L ^I«.ft7. ^KLH 11360.
COO? 714?«-. C001 74T19.
cons 37^. con*
CO OH
SKLL 4^S81. SKLH ITJB'.
f'li)? 19?10fr. C001 1?4317.
COOS *97. COO*
f ooa
^"^LL ^I'"i994. S^L^ ?07316«
c«op iyj^j^. cnoi isiftyh.
Cons 784. coo*
rnOH
F^f.F l?Hjqi. A ISP n.
FPFf-. l?rt')91. AISP 0.
r''Ft l/'vQ-JI. AJfJP n.
Fli(iqq?ol
FW199PO?
K»M99?0:i
FiVl 99?04
Kwiqgpos
FW199^n6
FWI99PO 7
FW19930H
FW199?n9
FW199J10
FW199?! 1
FUI199P1?
FW199P1 3
FW199P14
FV199?]1;
FIJI 9'3?l'r,
MW1 99?01
UIV) 9Q?0?
v!W199?03
"W199?0-*
MW199?OS
«W199?Oh
MW199V.07
"U199?n8
«W199?09
«W1 39? 1 0
UW199?1 l
•
CP!Vv?ni
•pp i QQP n ;.>
CP199?01
CP199?04
CP199POS
CP199PO*
PA199JOI
°A199?0^
PA199?0 )
P«199?01
PM) 9Q?n?
PMI99?03
PPI99201
PPl^qpO?
pp 1 99?n i
TABUE 5. FORMAT OF FIXSEWER OUTPUT
Water Dssnands By Planning Unit With Subset and Component Breakdowns
-------
PURPOSE
The purpose of the MUNWATRE program is to summarize the output
of the FIXSEWER program. It is printed as average daily, maximum daily or
peak hour municipal water requirement reports* Each report presents the
water demands by planning units and water usage categories. This program
was written to provide a quick summary of the water demand projections for
the specific model run. If the Framework Model were used only as a water
demand projecting tool, computation would stop with this summary.
CHARACTERISTICS OF OPERATIONS
Language; ANSI Cobol
Region; Program will execute in a 38K region plus the Buffer
Size. The sample run used 80K.
PROGRAM DESCRIPTION
The MUNWATRE program reads the water demand file, which is the
output from the FIXSEWER. program, and examines the SUBSET ID
RECORD. This ID, when matched to one of a set of literals established in
the program, initiates the proper branch instruction for the accumulation of
the subset data. The subset records axe then read in and the data values are
accumulated in one of three arrays; average daily, maximum daily, peak
hour. This process is repeated until an end of file signal is read on the input
file. The program then prints the number of planning units and total records
input and processed,
The control card file is then read and checked for a valid keyword. If
any keyword is mispelled, the program will terminate with an explanatory
message. The absence of any of the keywords will not cause the program to
stop, but the descriptive information in the report title or column headings
will be missing. The report type card then directs the program to print the
data from one of the three arrays. After the first report is printed the
control card file is read again for further descriptive information and
program type cards. This process is repeated until the end of file is reached,
at which time the program comes to a normal end of job.
66
-------
Sample Setup. See input-output flowchart
DATA SPECIFICATION
Input Description
Input to MUNWATRE is in the form of two files; the FIXSEWER output
file and the user control card file.
The input file is in the MAIN n water demand output file as corrected
by the FIXSEWER program. The MUNWATRE program will process an input
file with up to 100 planning unit sets of data. This input file is assigned to
DDNAME "WATERI1.
The user control cards supply the descriptive information needed for
the output print lines and also directs the program to print the required
reports. A minimum of four control cards are needed to produce one report.
If more than one report is to be printed, two control cards, a Title card and
Report Type card, must be added for each additional report with the Study
Year and Geographic Units Cards being optional. There are no default
values associated with the control card information. The Title card, Study
Year card and the Geographic Units card must precede the Report Type card
for first report. The control card file is assigned to DDNAME 'CARDI'.
The control cards for the program operation must be in the following
order:
CARD #1
Type: Title Card
Number: One for each report
Purpose; Supplies report, title for printout
Format: Col. 1-5 'TYPE =" keyword must becoded
67
-------
6-8 13 character description of report
i.e., 'AVERAGE DAILY1
19-80 Blank or user comments
CARD #2
Type: Report Type
Number: One for each report
Purposes Directs program to print one of the three summary
reports on water requirements
Format: Col. 1-4 'AVG' Print Average Daily water
requirements report
5-39 'MAX' Print Maximum Daily water
requirements report
'PEAK' Print Peak Hour water
requirements report
5-80 Blank or user comments
Output Descriptions
The MUNW'ATRE program prints an average daily, maximum daily
and/or peak hour water requirements report. Each report contains the
water demand by planning units and water usage categories.
68
-------
COMMERCIAL AVERAGE
DAILY REQUIREMENT
ALL VftLOES IN
COMM&NEQ SUBSET
PUBLIC AND UN-
ACCOUNTED MAXIMUM
DAILY RE
ALL
QUIHEMEW1
VALUES
FIGURE 8. PROGRAM FUNCTION FJXW3HART FOR
69
-------
FROM
FIXSEWER
GEOGRAPHIC
UNITS TITLE
STUDY YEAR
REPORT TITLE
#1
USER
CONTROL
CARDS
MUNWATRE
AVERAGE DAILY
WATER USAGE
\(
MAXIMUM DAILY
WATER USAGE
PEAK HOUR
WATER USAGE
FIGURE 9. INPUT-OUTPUT FICWCHART FOR MUNWATRE
70
-------
TABLE 6.
PLANNING
UNIT
SUMMARY OF ESTIMATED AVERAGE DAILY MUNICIPAL WATER REQUIREMENTS
FOR METROPOLITAN WASHINGTON FOR THE YEAR 1992
IN GALLONS PER DAY
RESIDENTIAL
COMMERCIAL &
INDUSTRIAL
PUBLIC &
UNACCOUNTED
TOTAL
SINGLE-FAMILY
HOUSEHOLDS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
DOMESTIC
4356817
16463076
4381677
956722
4859738
3886571
4212008
1467990
3084015
2093336
6115171
2229087
1140767
3571448
3478179
3097825
2727720
810571
1659102
2066139
1496740
844490
4285064
3585524
2409851
4800203
1803131
2716840
2767664
2142840
SPRINKLING
1225298
4488569
889041
298054
1428326
1072942
1635101
566191
1165977
880988
1619189
841398
364634
1095965
807556
763235
471155
254063
289097
234749
247041
159667
1375071
641602
445614
3210893
390937
640429
1570020
1377059
APARTMENTS
DOMESTIC
12681153
13781156
9357429
4110561
6172267
6527158
4281760
1899389
2642190
2508796
4356352
877112
1062724
2641285
2793188
1944925
1683002
284436
1346075
1305185
1130253
489559
2603629
2292818
1117460
2288620
1015209
2447821
2298965
2120934
SPRINKLING
2251144
2625892
1563795
804161
1153121
1190989
811744
352066
499038
448113
784351
167835
142596
462517
507445
358701
299249
54853
231931
225048
195729
92027
453810
395668
182739
477520
202466
438246
461690
401666
66163622
16521933
4066440
9636532
3312307
3992228
2534335
714225
3843552
817348
3956922
418642
1383518
1107632
1352786
1556273
821007
1178757
1520679
1106885
390946
224526
1287073
1046818
1202926
2425931
263526
2372064
1441694
1559889
5055394
7339756
4256157
1386776
3250471
3116138
2332376
962197
1561571
1390819
3110783
801356
945980
1926509
1832351
1425309
1332364
284248
1051732
1194427
889622
384164
2312153
1988256
1324057
1560220
695345
1595697
1261653
1190512
91733428
61220382
24514539
17192806
20176230
19786026
15807324
5962058
12796343
8139400
19942768
5335430
5040219
10805356
10771505
9146268
7334497
2866928
6098616
6132433
4350331
2194433
12316800
9950686
6682647
14763387
4370614
10211097
9801695
8792900
-------
TABLE 6 (continued)„
SUMMARY OF ESTIMATED AVERAGE DAILY MUNICIPAL WATER REQUIREMENTS
FOR METROPOLITAN WASHINGTON FOR THE YEAR 1992
IN GALLONS PER DAY
PLANNING
UNIT
RESIDENTIAL
SINGLE-FAMILY
HOUSEHOLDS
DOMESTIC
SPRINKLING
APARTMENTS
DOMESTIC SPRINKLING
COMMERCIAL &
INDUSTRIAL
PUBLIC &
UNACCOUNTED
TOTAL
-j
tv>
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
3233245
4432308
2124221
2455577
4917007
2733981
4833532
2863925
3870734
2178578
1783398
3388571
982800
1651511
3078472
455718
1471004
4519103
204973
780387
1014952
414546
2577940
1710909
628373
2974461
926224
1764310
678225
603040
1557628
206568
410305
842865
137605
430268
1024616
37409
3185263
5086556
1466278
3767204
3131183
2265045
4767501
2487711
5487138
1722980
2416217
4154231
759139
2626112
2611300
651531
1730507
4737840
425643
560526
891871
262595
759018
597842
416526
843054
440568
953914
289058
421464
727313
141662
453819
452153
105029
299594
828883
67756
911097
2728961
546895
2480593
1107094
2067271
3126143
4747627
4225585
1159976
1001554
1782467
243844
1194881
859002
913222
448425
4876175
330728
2026408
3020937
1100310
1601706
2198352
1478460
3037225
1683711
3025311
1330781
1349468
2418092
498607
1372924
1846211
390448
1031698
2963213
223675
10696926
17175587
5914845
13642038
13662387
9589656
19581916
13149766
19326992
7359598
7575141
14028302
2832620
7709552
9690003
2653553
5411496
18949830
1290184
TOTAL
150986778
49231417
154335019
27879983
173458249
90722787
646614233
-------
SEWAGE
PURPOSE
The sewage program is used to generate a file of average daily and
maximum daily sewage flows from the water requirements data estimated
by MAIN n. Either infiltrated or uninfiltrated flows can be calculated
depending on the program options selected by the user. The flows are
needed in order to project the hydraulic loads imposed on a treatment plant
by the sewage from each planning unit. In addition, the flows are multiplied
by user-specified pollutant coefficients (in mg/1) to produce estimates of
total sewage pollutant loads for biochemical oxygen demand (BOD), nitrogen
and phosphorus.
CHARACTERISTICS OF OPERATION
Language; IBM Fortran IV (G Level)
Region: Region size of least 150K, one 132 character/line printer,
one disk or four tape units.
PROGRAM DESCRIPTION
The sewage program produces a file of sewage flows and pollutant
loads for each planning unit. The program processes four input files. The
corrected MAIN H water requirements file (the FIXSEWER output file), the
constant pollution coefficients file (a user created file containing expected
concentrations in mg/1 of each pollutant by planning unit), the user control
card file (card file coded by user to supply information to the program) and
the optional infiltration quantities for each planning unit manually derived
from the developed land use forecast by the community development
component. The program writes two output files, the sewage flow and loads
file and a print file. The print file contains lists of the input data and
printed report of the calculated flows and loads. The sewage flow and loads
file is used in the TREATMENT program where it is identified by the name
"wastewater".
73
-------
The first operation performed by the program is to process the user
control card file. The first card input, which must be the Title Card, is
printed and saved for the future print operations. The second user control
card input must be the Planning Units Card. This card contains the number
of planning units on the MAIN n water requirements file. The third card
processed should be the Option Card. The Option Card contains the
FORTRAN unit assignments for the input and output files and provides the
user with the option to print the corrected MAIN n water requirements data.
The program then reads into an array the FIX SEWER data and prints
that data, if the user selected the print option.
The constant pollution coefficients file, created by the user, is read by
the program and entered into an array. The user must create a record
containing coefficients for each planning unit as there are no internal
program default values assumed for the pollution coefficients.
After all the records on the pollution coefficients file have been
processed, the user control card file is read and checked for pollution
coefficient updates. This User Control Card enables the user to specify
pollution coefficients to override those existing in the original file.
Coefficient updates, if present are inserted in the pollution coefficients
array. The User Control Card file is read until all the coefficients updates
have been input. The end of the updates is signaled by a 999 card.
The program checks for the presence of the optional infiltration
factors file by examining the Option Card for a FORTRAN unit number. A
zero FORTRAN unit number shows the file was not supplied. If the unit
number is other than zero, then the infiltration factors are read from that
FORTRAN unit number into an array to be used in the calculation of the
infiltration component of the sewage flows. In this optional file there must
be one infiltration factor for each unit. For each planning unit with no
specified infiltration factor a default value of zero is used.
74
-------
The sewage flows for the average daily and maximum daily require-
ments are computed by the following general equation:
Flow. = Demand. f.OOQOOl Adjustment.]! + Infiltration.
Where Flow, is the sewage flow for planning unit i
Demand^ is the sum of the commercial and domestic requirements for
planning unit i
Adjustment, is the calibration factor for planning unit i
.000001 is a factor to change the unit of measure to millions of gallons
per day
Infiltration is the amount in millions of gallons/day infiltrating the
sewer system.,
In the above equation when computing average flow, Demand- is
defined as the sum of the average domestic water requirements and the
average commercial requirements. When maximum flows are computed
Demand, is equal to the sum of the average residential domestic
requirements and maximum commercial requirements.
The sewage loads are computed by the following general equation:
Loadj. = | f~Dom.
Where: (
J f TComm. * COEFF2..1J * 1 8.34 [,000001 ]
I I
Load.. + the load in pounds per day of pollutant j for planning unit i
Dom. = domestic residential water requirements for planning unit i in
gallons per day
COEFF1.. = expected domestic concentration of pollutants in mg/1 for.
planning unit i
75
-------
Comm. = commercial water requirements for planning unit i in gallons
per day
COEFF2.. = expected commercial concentration of pollutant j in mg/1
for planning unit i
Constants change units of measure to pounds per day.
In the above equation, the domestic, variable is always equal to the
average domestic residential water demand. Commercial, is equal to the
average commercial water demand when computing average loads and is
equal to the maximum water demand when computing maximum pollutant
loads.
The flows and loads are computed for all planning units and stored in
an array from which they are retrieved for the printed report and the output
flows and loads file.
The printed reports include a table of the summarized domestic
residential and commercial water requirements and infiltration contribution
to sewage flow, a table of adjustment factors and pollution coefficients, and
a table displaying the average flows and pollution loads for each planning
unit.
After the last report is printed the program writes the output file
containing the average and maximum flows and loads and prints an end of
job message.
This output file will then be one of the two input files to the waste
treatment component.
SAMPLE SETUP
See the input - output flowchart for SEWAGE
76
-------
SCE COH-
IA1IT COEFTI-
;IENTS WITH
PDflTE COErFI-
CIEHTS
FIGURE 10. PROGRAM FUNCTION FLOWCHART FOR SEWAGE
77
-------
999 CARD
POLLUTION CO-
"EFFICIENT UP-
DATE CARDS
(OPTIONAL)
OPTION CARD
PLANNING
UNITS CARD
TITLE CARD
USER
CONTROL
CARDS
FROM
FIXSEWER
PROGRAM
INFIL-
TRATION
FACTORS
(OPTION
AL)
/CONSTANTS
[POLLUTION
IcOEFFI-
V CIENTS
ORRECTED
MAINZ WA-
TER DEMAND
FILE
SEWAGE
SEWAGE FLOWS
AND LOADS
FIGURE 11. INPUT-OUTPUT FLOWCHART FOR SEWAGE
78
-------
DATA SPECIFICATION
Input Description
The input to the SEWAGE program consists of two required data files,
one optimal file, and a set of User Control cards. The input data file is the
corrected MAIN H data from the FIXSEWER program. The FORTRAN Unit
number assigned to this file is coded on the Option Card,
The Constant Pollution Coefficients file, contained on disk or cards,
contains domestic and commercial coefficients for each pollutant. The
coefficients represent the expected concentration, in mg/1, of each
pollutant.
Constant Pollution Coefficients Format
COL. FORMAT DATA
1-3 13 Planning Unit Number- - Maximum value
of 100
4-10 F7.0 Adjustment factor (unitless) -used to
modify or calibrate total average and
maximum water requirements when
computing flows for each planning unit.
11-17 F7.0 BOD Coefficient - Domestic expected
concentration in mg/1
18-Z4 F7.0 BOD Coefficient - Commercial expected
concentration in mg/1
Z5-31 F7.0 Nitrogen Coefficient - Domestic expected
NO, (as N) concentration in mg/1
3Z-38 F7.0 Nitrogen Coefficient - commercial expected
NO, (as N) concentration in mg/1
39-45 F7.0 Phosphorus Coefficient - Domestic expected
'~"4 (as P) concentration in mg/1
46-5Z F7.0 Phosphorus Coefficient - Commercial
expected concentration mg/1
79
-------
The optional infiltration factors file supplies the number of gallons
of water in mg/d that seeps daily into the sewer system. If this file is
present it must contain one record for each planning unit.
Infiltration Factors Format
COL. FORMAT DATA
1-3 13 Planning Unit Number - Maximum value
of 100
4-13 F10.0 Infiltration Factor - number of gallons
of water infiltrating the sewer system
in millions of gallons per day
Four User Control Cards supply the descriptive information for the
output print lines. They also provide for optional print and updates
procedure. The control card file is assigned to the DDNAME '
The control cards for the program operations are:
CARD #1
Type: Title Card
Number: One - required
Purpose: Supplies report title for printed report
Format: Col. 1-80 - Free Form
80
-------
CARD #2
Type: Number of Planning Units
Number: One
Purpose: Sets upper limit on number of planning units input to the
program.
Format: Col. 1-5 - Integer number 1-100 for number of planning
units.
Col. 6-80 - Blank
CARD #3
Type: Run Option Card
Number: One
Purpose: Gives user the option of printing the programs input data,
which is the modified MAIN H data from the FIXSEWER
program
Format: Col. 1-4 - Input FORTRAN unit number for modified
MAINE
5-8 - Input FORTRAN unit number of default coefficients
9-12 - Output FORTRAN unit number
13-16 - T if modified MAIN n data is to be printed.
'0' if modified MAIN n data is not to be printed.
17-ZO - Input FORTRAN unit number of infiltration
factors
21-80 - Blank
CARD #4
Type: Update Coefficient Cards
Number: One card containing 999 in Col. 1-3 must be present.
Up to 100 data cards may precede this card, one per planning
unit unit to be updated.
Purpose: Gives the user the option to substitute new pollution coefficients
for the constant pollution coefficients.
Format: Col. 1-3 = 999 data end of update cards. Otherwise these
columns confirm the number of the planning unit to be
updated.
81
-------
The format for completing the update is:
F7.0 Col. 4-10 - Adjustment factor
F7..0 11-17 - BOD Coefficient - domestic
F7.0 18-24 - BOD Coefficient - commercial
F7.0 25-31 - Nitrogen Coefficient - domestic
F7.0 32-38 - Nitrogen Coefficient - commercial
F7.0 39-45 - Phosphorus Coefficient - domestic
F7.0 46-52 - Phosphorus Coefficient - commercial
F7.0 53-80 - Blank
Output Descriptions
The SEWAGE program lists ail User Control Cards read and prints
reports that include a water requirements table for the domestic, commer-
cial and public sectors, a pollutant coefficients table, and a sewage flow and
loads table. The printfile is assigned to DDNAME 'Ft06F001°.
An output tape containing the sewage flow and loads table is produced
for use as input to the TREATMENT program. The FORTRAN unit number
assigned to this file is coded on the option card.
A User Option Card prints the modified MAIN II dataset (the
FIX SEWER output file).
82
-------
EM PDA
PURPOSE
The purpose of the EMPDA program is to convert the EMPIRIC Model
output datasets into easily usable files for further processing. EMPIRIC
variables are manipulated and combined with EMPDA card input data to
produce new data variables by PAD such as Households per acre and median
income. Forty-three variables are produced by EMPIRIC. EMPDA computes
15 new variables and places them hi fixed locations in the EMPDA output
format. Additional space is allocated in the output format. Additional
space is allocated in the output record to permit further data additions while
retaining the same 800 character record length. Other geographic areas
(groupings of PADs) are also identified and placed into each PAD record and
maintained in the EMPDA file for later use. The resultant output file is thus
available for further processing by any programs requiring EMPIRIC data.
CHARACTERISTICS OF OPERATION
Language; PL/1
Region; 210K for the Sample Program
PROGRAM DESCRIPTION
The EMPDA program first reads and prints the parameter card. The
first record of the EMPIRIC data file is read and matched against the
identification information contained in the parameter card. If the TO
information fails to match, an error message is printed, as well as the
EMPIRIC ID, and the run is terminated.
After a successful ID match, the program reads the 37 area system
cards, (146 PADs - 4 fields/card), stores and prints the data. The program
then creates additional data variables, based on the EMPIRIC data and
parameter card information, and creates an EMPDA. output record for each
of the 146 PADs. The basic 43 EMPIRIC variables are utilized to create an
additional 15 variables (see Program Function Flowchart), If the print
83
-------
option was selected, a 'P1 in column 10 of the parameter card, each output
data record is formatted and printed. Jurisdictional and variable totals are
computed and the PAD record is stored for later output in PAD sequence
number order. After all 146 PADs have been processed, grand totals are
accumulated by variable and jurisdiction and a summary report produced.
The EMPDA file is then written out on tape in ascending PAD sequence
number order (file format name EMPDA), Selected metropolitan summaries
are printed and processing ends.
SAMPLE SETUP:
See Input-Output Flowchart
84
-------
/ EMPIR J^
^* _J
Compute Total Land Area - V97
Compute Total Population - V93
Compute Total Employment - V92
Compute Total Labor Force - V91
Compute Median Income Code
(0.5-3.5) - V62
Gave Income Quartile & Boundaries
V94, 95, 96
Compute Total Households - V69
Compute Gross HHs/Acre - V63
Compute Net HHs/Res. Acre - V64
Compute Net Emp. Density - V65
Compute Ration Used/Used+Vac - V66
Compute Ration Used/Total - V67
Compute Activity Density Index-V68
Move EMPIRIC Data and Area Systems
Data to Save Matrix (PAD #)
CONVERT
IEDIAN INCOME
CODE TO
DOLLARS
s
ACCUMULATE
VARIABLE
TOTALS
COMPUTE RATIC MUL-
TIFAMILY HH TO
TOTAL HH: COMPUTE
RATIO PARK G REG-
LAND TO TOTAL
USED LAND
SELECT DATA
BY PAD IN
ASCENDING
SEQUENCE
\
f
FIGURE 12. PROGRAM FUNCTION FLOWCHART FOR EMPDA
85
-------
PARAMETER
CARDS
(1)
EMPDA
AREA
I SYSTEMS (37)
FIGURE 13. INPUT-OUTPUT FLOWCHART FOR FMPDA
86
-------
DATA SPECIFICATION
Input Descriptions
There is one major input file to EMPDA, the raw EMPIRIC dataset as
generated by the EMPIRIC Activity Allocation Model. The format of this
file is EMPER (see Appendix B). The DD NAME for this file ia AAL Other
inputs are as follows:
EMPDA Parameter Card
Data Card Cols:
Required ID 1-3 1st PAD Dist bbi from EMPIRIC
Match C4 Blank
EMPIRIC 5-6 Forecast Year
Dataset 7-8 Data Set # - Alt Tested
9 Run Number
10 'P' if each PAD Variable should be printed
12-19 Low $ Median
20-27 Low/Low Mid $ Boundary
28-35 Middle $ Boundary
36-43 Upper Mid/Upper $ Boundary
44-51 Upper $ Median
73-80 Date MM/DD/YY
EMPDA Area Systems Cards
1-3 PAD Number (001-875)
4 Blank
5-7 PAD Sequence Number (001-146)
& Blank
7-11 TPB Superdistrict Number (001-052)
12 Blank
13-15 Density Area Code (01, 02, 11, 12)
16 Blank
17-19 EPA Areas (001-027)
20 Blank
87
-------
EMPDA Area Systems Cards
1-3 PAD Number (001-875)
4 Blank
5-7 PAD Sequence Number (001-146)
8 Blank
7-11 TPB Superdistrict Number (001-052)
12 Blank
13-15 Density Area Code (01, 02, 11, 12)
16 Blank
17-19 EPA Areas (001-027)
20 Blank
Above repeated 4 data fields per card 37 cards for 146 PAD's
Output Descriptions
The EMPDA program writes one output data file (format EMPDA)
The DD NAME for this file is AAO. An optional output is a listing of all
output data variables. Standard printer output includes:
Display of Parameter Card
Any Error conditions encountered
Summary Printout of Variables by Jurisdiction
Metropolitan Averages of Selected Indicators.
-------
PRESTORM
PURPOSE
Prestorm prepares data for the Stormwater Management Model. The
model allocates EMPIRIC population and land use from the Policy Analysis
Districts (PAD) to watersheds using a table prepared by planimetering the
intersections of each of the areas. In doing this, the assumption was that
population was uniformly distributed across the PAD and that planimetering
the areas was an adequate method for estimating population by watershed.
PRESTORM applies correlation equations that relate the densities of
activities from EMPIRIC output to imperviousness for use hi the Stormwater
Management Model. PRESTORM also calculates necessary physical water-
shed data and inserts information on the type of storm to be simulated for
use in Stormwater prediction in the subsequent model.
PRESTORM allows updates of input materials or the use of previously
calculated values.
CHARACTERISTICS OF OPERATION
Language; IBM FORTRAN IV (G Level)
Region: Region size of at least 176K. A minimum of one disk
or two tape units are necessary, as well as one 13Z character
line printer.
PROGRAM DESCRIPTION
The PRESTORM model reads a series of User Control Cards and a
tape/disk file, either an EMPDA file or optionally a PRESTORM runoff
matrix file, and writes a tape or disk file that can be input to the
Stormwater runoff model without any additional modifications. The optional
output of PRESTORM is a file, the Runoff Matrix File, which can be used as
input in place of an EMPDA data set.
89
-------
The operation of the program begins with the processing of the User
Control Cards. As each card is read, it is validated for proper format and
Sequence. A Control Card containing format errors or appearing out of
sequence will be identified by a printed message. The program will
terminate if any of the aforementioned conditions occur.
The Title Card and Card Type i are read and printed. If an EMPDA
file was selected for input, subroutine I2INIT is performed. I2INIT inserts
blanks or zeroes into the runoff matrix as required. The runoff matrix is an
array that holds all the data values for the executive and runoff control
block card groups that are input to the stormwater runoff model. If the
optional input, the runoff matrix file, was selected it is input directly into
the runoff matrix.
If the runoff matrix is to be updated, a Card Type #2 would be the
next Control Card processed. Type 2 or 5 Cards contain new values to be
entered into the runoff matrix. If any value is to be set equal to zero, a
minus one (-1) is copied for that value. The update is completed and control
is returned to the main program where the next Control Card is read.
The Card Type #3, if supplied, invokes subroutine I2DEF. This
program enters default values into the runoff matrix for runoff card groups
5, 7 and 18.
If the EMPDA file was selected as input, the next control card
transfers program control to subroutine 12EMP. 12EMP processes the
EMPDA file and the user file in allocation Policy Analysis Districts to
watersheds. Population, households and employment data is aggregated to
watersheds and either entered directly into the runoff matrix or used to
compute additional data items. The equation derived at COG to
estimate a measure of imperviousness from population density is applied as
is the equation estimating total length of gutters.
90
-------
The results of these computations are stored in the Runoff Matrix and
control is returned to the main program.
The Card Type #5 would occur next if the user desires to override any
of the data items calculated from the EMPDA data. The same operations
are performed for a Card Type #5 as a Card Type #2.
The Card Type #6 directs the program to read additional input in the
form of Runoff Cards Groups. This data is appended to the standard
program output card groups and is not verified or inspected for format or
logic errors.
The output operations are signaled by the use of Card Type #7's. The
runoff matrix is formated to correspond to the required card group formats
for the executive and the runoff blocks of the Stormwater Management
Model. The formated data can be printed and/or written to a tape or disk
file to be read directly by the stormwater runoff model. The Runoff Matrix
itself can be written to a tape or disk file and used as input to a future run
of the PRESTORM model.
The Card Type #7's must be followed by a Card Type #9 to signify the
end of the User Control Cards and to terminate the program operation.
There is no Card Type #8.
SAMPLE SETUP: See Input - Output Flowchart.
91
-------
FIGURE 14. PKESTORM PROGRAM FUNCTION FLOWCHART
92
-------
PRESTORM
MAIN
PROGRAM
S.
.-*
s
^
*•*"
S
"
"^
*r
^
%
S
S
**.
s
f'
\.
SUBROUTINE
I2INIT
SUBROUTINE
I2UPD
SUBROUTINE
I2DEF
(DEFAULT)
SUBROUTINE
I2EMP
SUBROUTINE
I2UPD
^ SUBROUTINE
EMPIRIC
f
^
FIGURE 15. PRESTORM SUBROUTINE LINKAGE
93
-------
CARD TYPE #9
END OF CONTROL
CARD TYPE #7
OUTPUT CONTROL
CARD TYPE #6
OPTIONAL
CARD TYPE #5
OPTIONAL
CARD TYPE #4
EMPDA INPUT
CARD TYPE S3
DEFAULT
CALCULATIONS
CARD TYPE #2
OPTIONAL
CARD TYPE #1
INPUT SELECTION
OPTIONA
INPUT RUN
FF MATRIX
LAND
USE
CHARACTER
ISTICS
PTIONAL
OUTPUT RUN
OFF MATRIX
RUNOFF
INPUT
FILE
TO
STORMWATER
RUNOFF
MODEL
FIGURE 16. PKESTORM INPUT-OUTPUT FLOWCHART FOR PRESTORM
94
-------
DATA SPECIFICATION
Input Description
The PRESTORM program input consists of a series of User Control
Cards, a User Supplied file and a tape or disk file output by the EMPDA
program. An alternate Input, replacing the EMPDA file, is a Runoff Matrix
file generated in a previous run of the PRESTORM model.
The data file created by the EMPDA program from the EMPIRIC data
contains summarized land use characteristics for each planning analysis
district. This file must be sorted prior to its use as input to the PRESTORM
model. The sort is ascending in the following order: COL. Z, COL. 1 then
COL. 3.
The optional runoff matrix file is a file produced by an earlier run of
the prestorm program. The file contains all the data values needed to
construct the input file for the stormwater runoff model.
The User Control cards supplied to the PRESTORM model must be
submitted in the order that they are described here. Failure to do so will
cause the program to terminate. The function and format of each of the
nine card types is as follows:
Type: Title Card
Number: One - Required
Purpose: Supplies Report Title For Printed Output
Format: COLS Format Data
1-8 ZOA4
Free Form Descriptive
Data
-------
Type; Card Type #1
Number: 1 Only
Purpose: Specify Type of Input
Format: COLS Format
1 II
7 II
14-15
12
Data
Card ID T
1= EMPDA File Input
2= Old PRESTORM
Runoff Matrix Input
FORTRAN unit number
of Runoff Matrix if
COL. 7=2
Type: Card Type #2 or #5
Number: As Required
Purpose: Supply or update storm and watershed data
Format: COLS Format Data
1 II
6-7
14-15
16-20
12
12
15
2= Update matrix prior
to Default and EMPA
Calculations
5= Update Matrix after
Default and EMPDA
Calculations
R= Enter Runoff Block
Data
E= Enter Executive
Block Data
B= Enter Runoff Data
Coefficients
Number of card to
be updated
Runoff Block: 1-18
Executive Block: 1-6
Number of Update
cards following this
card
Number of Watersheds
(Optional) used if COL.5=B
96
-------
Type: Card #3
Number: 1 only (Optional)
Purpose: This card initiates the default calculations
Format: COLS Format Data
1 II '3' Card Type ID
Type:
Number:
Purpose:
Format:
Card #4
1 only
Directs program to read an EMPDA data set
COLS
1
7
10-11
Format
II
II
12
Data
'4' Card Type 3D
1= Print EMPDA data
for each policy analysis
district
0= Do not print EMPDA
data FORTRAN unit
number assigned to
EMPDA data set.
Type:
Number:
Purpose:
Format:
Card Type #6
1 only (Optional)
Permit the input of additional data - a second set of runoff
data or data to be input to the graphing programs
COLS
1
10-11
14-15
Format
II
12
Data
'6' Card type ID FORTRAN
FORTRAN unit number
assigned to additional
data set
Number of data cards
in the additional data
set.
Type: Card Type #7
Number: As Required
Purpose: Specify the type and FORTRAN unit number of each output
Format: COL Format Data
1 II
7' Card Type ID
1= Print runoff matrix
2= Write stormwater
runoff input data matrix
3= Write runoff matrix
- optional input to PRESTORM
97
-------
10-11 12 FORTRAN unit number
assigned to output file
if COL 7= 2 or 3
Type: Card Type #9
Number: 1 only
Purpose: Indicate end of User Control Cards.
Format: COL Format Data
1 II '9' Card Type ID
The user supplied file contains records allocating a certain percentage
of a Policy Analysis District to a watershed.
The maximum number of records for this file1 is one thousand. This file
must be supplied when the EMPDA data set is selected as input. It is
assigned to the FORTRAN unit number 20.
Format: COLS Format -Data
1-2 12 Watershed number
or '99' if last record
5-7 13 Policy Analysis District
10-12 13 Percentage of PAD
allocated to watershed.
Output Description
The PRESTORM model prints the User Control Cards and writes a tape
or disk file that can be input directly to the Stormwater Management Model.
An optional output is a tape or disk file containing the runoff matrix.
The Stormwater Management Model input file contains, in card image
format, the eighteen card groups required by the runoff block and first six
card groups required by the executive block of the model.
The runoff matrix file contains all the data values used to construct
the runoff model input file. This file is the optional input to the PRESTORM
model.
Printed output consists of a listing of all User Control Cards and,
optionally, the EMPDA input data and/or the Stormwater runoff model data
produced by PRESTORM. The print file is assigned to FORTRAN unit
number 6.
98
-------
STORMWATER RUNOFF COMPONENT
PURPOSE
The storm water runoff component of the Framework system is
designed to simulate the stormwater runoff which occurs in a drainage basin
during a specified rainfall pattern. For the design storm the quantity and
quality of the stormwater over time is calculated. This computation
provides essential data for planning and design of flooding and pollution
control strategies in the basin.
The model simulates the watershed as a series of sub-catchments
connected by gutters, determines precipitation, infiltration to the soil,
surface water detention and flow over the land. The accumulation and
subsequent washoff of dust, dirt, and BOD are also calculated and combined
with quantity calculations to determine concentration. Hydrographs of
water quantity at specified points in the system and pollutographs are
outputs of the model.
MODEL INPUTS
Precipitation
The model requires a rainfall hyetograph (inches per hour by time
interval) time history of a storm — which is determined from analyses of
Weather Bureau data.
Description of Watershed
The following items are required to adequately describe the physical
features of a watershed which affect the rainfall runoff:
Watershed
Area (acres)
Length: width ratio
Overland flow slope
99
-------
Stream by Watershed
Length of main stream (ft.)
Width of main stream (ft,)
Slope of main stream (ft.)
Coefficient of roughness (Manning's n)
Land Use by Watershed, each expressed as a percentage of the total
area,
Residential
Commercial
Industrial
Undeveloped
Imperviousness and other physical data
Impervious area coefficient of roughness
Impervious area detention depth (in.)
Pervious area coefficient of roughness
Pervious area detention depth (in.)
Pervious maximum infiltration rate (in./hr.)
Pervious area minimum infiltration rate (in./hr.)
Pervious area decay rate of infiltration (sec-1)
Curb Length (ft./land use area) by watershed
Watershed and stream geometry and physical features are determined
by analysis of U.S. Geological Survey topographic maps and knowledge of the
area to be studied. Land use for each watershed is determined from the
Community Development Component which is retabulated into watersheds
by the interface program PRESTORM. The percentage of land by land use is
used in the model to determine the average accumulation rate of pollutants
on the land surface. This rate varies by land use. Of all the factors which
describe a watershed, sensitivity analyses have shown that imperviousness
and curb length have the greatest impact on rainfall runoff quantities and
17
quality. Both of these parameters may be calculated from manual
reductions of aerial photographs—measuring the length of roads and areas of
imperviousness. This process is time consuming and in addition cannot be
used for analysis of future development patterns, As an alternate technique
17
analysis at the Council of Governments has shown that imperviousness
and curb length can be estimated with A relatively high degree of reliability
(r=0.9) from household and employment densities. More recent analysis of
the correlation data for this region between measured imperviousness and
curb length to household and employment densities has yielded the following
relationship. 100
-------
I = 96,6 - 18.7 (0,8927) ED - 54.2 (07.7889) HD
C = 427.4 - 388.1 (0.6899)HD
Where
I = Imperviousness (percent)
ED = Employment Density (Employment percent)
HD = Household Density (Household percent)
C = Curb length (ft per acre)
MODEL CALCULATIONS
The model calculates the hydrograph by a step-by-step accounting of
rainfall, infiltration detention and flow. Rainfall is added to each
catchment according to the input hyctograph (rainfall jn inches per hour) by
the procedues used in the EPA Storm Water Management Model/8 a-
summarized below:
1= Rainfall is added to the subcatchment according to the specified
hyetograph
D1=Dt + RtAt (1)
Where Dj = Water depth after rainfall
D. = Water depth of the subcatchment at time, t
R. = Intensity of rainfall in time interval,At
17
P. Graham, L. Costello. and H. MaiJon, "Estimation of Imperviousness
and Specific Curb Length for Forecasting Stormwater Quality and Quantity,"
Journal of the Water Pollution Control Federation, (April, 1974).
101
-------
2. Infiltration is computed by Morton's exponential functional and is
subtracted from water depth existing on the subcatchment,
\ - fo + «1 -V
and
(3)
Where f , f . and a are coefficients in Morton's equation
o' i ^
3. If the resulting water depth of the subcatchment, D_, is larger than
the specified detention requirement, D ,, an outflow rate is computed
using Manning's equation,
V = ^9 (D _ D , 2/3 sl/2
n 2 d
and
Qw = V W (D2 - Dd)
where V = Velocity
n = Manning's coefficient
s = Ground slope
W = Width
Qw = Outflow rate
The continuity equation is solved to determine the water depth of the
subcatchments, resulting from the rainfall, infiltration, and outflow,
Dt+At = D2-(Qw/A)At (6)
where A is the surface area of the subcatchment
5. Steps 1 to <4 are repeated until computations for all subcatchments
are completed.
102
-------
6. The inflow (Q- ) to a gutter is computed as a summation of outflow from
tributary subcatchments (Qw .) and flow rate of immediate upstream
gutters (Q .).
M51
Qin - E QWji + E Qg?i (7)
7. The inflow is added to raise the existing water depth of the gutter
according to its geometry,
YI = Yt + (Q.n/ Ag) A t (8)
where YI and Yt = Water depth of the gutter
A - Mean water surface area between Y. and Y
s It
8. The outflow is calculated for the gutter using Manning's equation,
V = M2 R2/3S 1/2 (
n i
and
Q = V A (10)
where R = Hydraulic radius
S. = Invert slope
A = Cross-sectional area at Y.
9. The continuity equation is solved to determine the water depth of the
gutter, resulting from the inflow and outflow.
Yt+At = Yj + (Qin - Qg)At / As (11)
10. Steps 6 to 9 are repeated until all the gutters are finished.
11. The flows, reaching the points of concern, are added to produce a
hydrograph coordinate along the time axis.
102-a
-------
SPLIT
PURPOSE
The stormwater runoff component determines the amount of storm-
water which flows from a watershed by means of a natural drainage system.
This 'natural flow' from a watershed is reduced proportionately to the
coverage of a watershed by storm sewers and/or combined storm and
sanitary sewers. The SPLIT program is the vehicle used to allocate the
stormwater runoff flows and loads to separate files of sewered areas where
flows are potentially treatable, or to unsewered areas where natural flows
and loads will be discharged directly into streams. These discharges are
analyzed for input to the hydrodynamic model in the receiving water
component. This distinction is made so that different assumptions about
travel and treatment can be made at a later stage in the chain of models.
CHARACTERISTICS OF OPERATIONS
Language; IBM FORTRAN IV (G Level)
Computer Requirements;
Split requires a minimum of 50K in which to execute. At least one
disk unit or three tape units are required for the input and output files. The
printed reports require one 132 character line printer.
PROGRAM DESCRIPTION
The SPLIT program inputs two files, the stormwater runoff file
produced in the stormwater runoff component and the constant split
percentages file (a user file containing for each watershed the percentage of
stormwater runoff entering the sewer system), and one card file containing
two User Control Cards. The program output consists of two files
containing runoff flows and loads, one for the sewered runoff and the other
for unsewered or 'natural' runoff. Printed reports listing the User Control
Cards, the tabel of constant split percentages, the runoff flows and loads
from the stormwater runoff component, and a table of the split runoff flows
and loads.
103
-------
The SPLIT program was written to perform the computations for 65
watershed areas. If the number of watersheds output by the stormwater
runoff component is not equal to 65, the program must be modified to
accommodate the new number of watershed areas.
The program begins operation by initializing the number of watersheds
to be processed to 65. The User Control Card file is read and the first card,
the Title Card, is printed. Second, the Control Card is read and printed. It
assigns FORTRAN unit numbers to the input and output files.
The constant split percentages file is read into an array and printed in
report form. This file contains, for each watershed, the percentage of the
flow and the percentage of the three pollutants, BOD, Nitrogen and
Phosphorus that enter the sewer system in that watershed.
The stormwater runoff file is read, entered into an array, and then
printed in report form. The runoff flows which input in units of cubic feet
are converted to gallons.
The sewered stormwater runoff flows and loads for all watersheds are
now calculated. The sewered flow of a watershed is computed as:
SFLOWW = [RFLQWW I |"SPCTW"|
Where: SFLOW,^ = Sewered runoff in gallons to receive treatment
RFLOW™. = Stormwater runoff for watershed hi gallons
SPCT™. = Percentage of runoff collected into the sewer system
in watershed W
The sewered pollutant loads of a watershed are computed as;
SLOADWJ^[RLOADWJ][SPCETWJ]
104
-------
Where: SLOADWJ = Load of pollutant J in Watershed W
to receive treatment
RLOADWJ = Runoff load of pollutant J in Watershed W
SPCTWJ - Percentage of pollutant J in Watershed W
collected into sewer system
The sewered or 'natural' flows and loads are the differences between the
runoff flows and loads and the sewered flows and loads. The calculations
having been completed, the output function of the program begins.
The output tape or disk files are written, one containing the sewered
flows and loads, the other the unsewered, and a report for both sewered and
unsewered flows and loads is printed. Program operation terminates at the
completion of the output process with a printed message to confirm a
successful run.
SAMPLE SETUP: See Input-Output Flowchart
105
-------
START
\ READ/PRINT
\ UNIT
\ASSIGNME:
\ CARD
READ/PRINT
CONSTANT
SPLIT
PERCENT.
FILE
READ/PRINT
STORMWATER
RUNOFF
FLOWS £
LOADS
WRITE
VUNSEWERED
FLOWS S
LOADS
FILE
PRINT
\ SEWERED
\S UNSEW.
\FLOWS &
\ LOADS
\/
STOP
FIGURE 17. PROGRAM FUNCTION F1CWCHART FOR SPLIT
106
-------
FROM
STORMWATER
RUNOFF MODEL
''UNIT ASSIGNMENT
CARD
TITLE CARD
SPLIT
SEWERED
RUNOFF
FLOWS AND
LOADS
TABLE OF SPLIT
PERCENTAGES
TABLE OF SEW-
ESED AND UN-
SEWERED F:
SEWERED
RUNOFF
FLOWS AND
LOADS
TO THE
RECEIVING
WATER COMPONENT
TO
TREATMENT
FIGURE 18. INPUT-OUTPUT FLOWCHART FOR SPLIT
107
-------
DATA SPECIFICATION
Input Description
The split program reads one tape or disk file containing the flows and
loads estimated for each watershed by the stormwater runoff component,
and one tape, disk, or card file containing, for each watershed, the
percentage of stormwater runoff entering the sewer system. Two user
control cards complete the input requirements.
Runoff flows and loads file is produced by the Stormwater Runoff
Component. It contains the flows and loads expected to result from the
occurrence of a storm event defined by its intensity and duration. The file
is assigned to the FORTRAN unit number coded on the unit assignment card.
Constant split percentage file is a user created file containing the
percentage of runoff entering the sewer system. These percentages are
applied to the runoff flows and loads to compute the sewered and unsewered
runoff flows and loads.
CONSTANT SPLIT PERCENTAGES FILE FORMAT
COLS. FORMAT DATA
1-3 13 Watershed number
(Maximum 65)
4-10 F7.3 Percent of flow collected
into storm or combined
sewer system
H-17 F7.3 Percent of BOD load
collected into storm
or combined sewer
system
18-24 F7.3 Percent of Nitrogen
load collected into
storm or combined
sewer system
108
-------
25-31 F7.3 Percent of Phosphorus
load collected into
storm or combined
sewer system
32-80 49X Blank
The percentages are coded in the form XXX.XXX, i.e, Z5 percent would
be coded 25.0
Two User Control Cards are required. One provides descriptive
information for the printed report, the other assigns FORTRAN unit
numbers to the input and output files.
CARD #1
Type:
Purpose:
Number;
Format:
Title Card
Supply descriptive information for printed reports
1 only
Col. 1-80 - Free form comments to describe stormwater
runoff data
CARD #2
Type:
Purpose:
Number:
Format:
Unit Assignment Card
Assign FORTRAN unit numbers to the input and output
files
1 only
Cols^
1-4
5-8
9-12
13-16
Format
14
14
14
Data
Unit number of constant
split percentages file
Unit number of stormwater
runoff file
Unit number of sewered
runoff file
Unit number of unsewered
runoff file
109
-------
Output Description
The SPLIT program output consists of two tape or disk files, one
containing the sewered runoff flows and loads, the other containing the
unsewered runoff flows and loads, and printed reports of the input and
output data.
Sewered stormwater file containing the flows and loads that enter the
sewage system. These flows and loads will be treated by the waste
treatment management component. The file is assigned to the FORTRAN
unit number coded on the Unit Assignment Card. Unsewered stormwater
runoff file containing the flows and loads that enter directly into the estuary
without any treatment. The file is assigned to the FORTRAN unit number
coded on the Unit Assignment Card.
A report is printed listing the sewered and unsewered loads and flows
for each watershed which are used in the Receiving Water Component (See
Table 8). In addition, the User Control Cards, the constant split
percentages file, and the runoff flows and loads estimated by the
stormwater runoff component are printed. The print file is assigned to
FORTRAN unit number 6,
110
-------
TREATMENT
PURPOSE
The purpose of the TREATMENT program is to provide the means to
simulate alternative waste treatment management options, and to summa-
rize their effect on the wastewater flows, loads (estimated by the Sewage
Generation Component), the stormwater runoff flows and the loads
(estimated by the Stormwater Runoff Component).
The combined treated sewage flows and pollutant loads calculated by
the TREATMENT program are analyzed and the relevant data is extracted
and prepared for use in the Receiving Water Component.
CHARACTERISTICS OF OPERATION
Language; IBM FORTRAN IV (G Level)
Region; A minimum region size of 8OK is required. The program requires
at least one disk or four tapes, a card reader, and a 132-character per
line printer.
PROGRAM DESCRIPTION
The TREATMENT program reads two tape or disk files, (the
wastewater and stormwater flows and loads}, a User Control Card file, and
three User Created files that may reside on card, disk or tape. These inputs
provide the program with the information necessary to calculate the residual
pollutant loads discharged by each sewage service .area into the estuary.
One output file is created, a tape or disk ?il2 containing combined treated
sewage flows and loads. Printed reports of both input and output data are
also produced.
111
-------
The first step in the program operation is the processing of the User
Control Cards. The first card, the Title Card, is read and printed. The Title
Card will also be printed at the top of each report. The second card input
should be the Service Areas Card. This card contains the number of planning
units and watersheds that will be read from the Wastewater and Stormwater
files, and the number of Sewer Service Areas that will be written to the tape
or disk output file. The last User Control Card supplies the FORTRAN unit-
numbers for the five input files.
The three User-Created files are processed next. The Sewage Service
Area Assignments file is composed of two groups of records. Each group is
identified by a two-digit record identification. The first group assigns
sewage service areas to watersheds while the second assigns service areas to
planning units. The second user file processed is the Sewage Service Area
Treatment Efficiencies file. This file contains pollutant removal
efficiencies for each sewage service area. The efficiencies are represented
as the percentage of each pollutant (BOD, Nitrogen, and Phosphorus) that
would be removed by a treatment facility located in a sewage service area.
The third file, the Description File consists of three groups of records. One
group contains geographic descriptions of watersheds. The remaining groups
contain planning unit and sewage service area descriptions.
The Wastewater and the Stormwater Runoff files are processed next.
If the number of watersheds or the number of planning units coded on the
Service Areas Card is zero, the processing of the corresponding flows and
loads file is skipped. When the input operations are complete, the
calculation of the treated effluent begins.
The effluent computation is a two-step process. In the first step, the
flows are aggregated to sewage service areas by means of the sewage
service areas assignments. In the second step, the residual pollutant loads
are computed by means of the sewage service area treatment efficiencies.
The process is performed twice, once to compute average treated flows and
loads and once to compute maximum flows and loads. The treated flows and
loads are summed to yield a table of combined treated sewage flows and
loads. The resultant combined treated flows table can then be used to assist
112
-------
in the determination of the quantity, location and characteristics of point
source discharges needed by the estuary component.
The output operation prints and writes to a tape or disk file the
treated flows and loads for both the input components and the computed
combined sewage effluent. The output process completes the program
operation.
SAMPLE SETUP - See Input Input-Output Flow Chart
113
-------
FIGURE 19. PROGRAM FUNCTION FLOWCHART FOR TREATMENT
114
-------
7
SEWAGE SERVICE
AREA, WATERSHED,
PLANNING UNIT
DESCRIPTIONS
SEWAGE SERVICE
AREAS TREATMENT
EFFICIENCIES
CARD/TAPE/DISK
SEWAGE SERVICE
AREA
ASSIGNMENTS
/-'INPUT-OUTPUT
UNIT ASSIGNMENT
CARD
f'SERVICE AREAS
CARD
FROM
SEWAGE
PROGRAM
FROM
SPLIT
PROGRAM
EFFLUENT FLOW!
AND LOADS
/EFFLUENT
/FLOWS AND
I LOADS
FIGURE 20. INPUT-OUTPUT FLOVCBMCT FOR TREATMENT
115
-------
DATA SPECIFICATION
Input Description
The TREATMENT program input consists of one card file (the User
Control Cards) and two tape or disk files (the output file from the SEWAGE
program and the sewered output file form the SPLIT program). In addition,
three user-created input datasets may reside on cards, tape or disk.
The User Control Cards are required for each euu of treatment. The
cards must be submitted in the same order as they are described here. The
file is assigned to FORTRAN Unit #9.
CARD #1
Type:
Purpose:
Number:
Format:
Title Card
Supply Descriptive Information for Printed Reports.
1 only
Col. 1-80 - Comments to describe treatment run.
CARD #Z
Type:
Purpose:
Number:
Formats
Card #3
Type:
Purpose:
Number:
Service Areas Card
Allow variable number of sewage service areas, planning
units and watersheds.
1 only
Col. 1-2 - 12 - # of sewage service areas (max=50)
3 - Blank
4-5 - IE - # of watersheds (max=99)
6 - Blank
7-8 - 12 - # of Planning Units (max=99)
FORTRAN Unit Assignment Card
Assign FORTRAN unit numbers to input files.
1 only
116
-------
Format: Col. 1 - II - T identification
2 - X - Blank
3-5 - 13 - FORTRAN unit number for service
area data set
6-8 - 13 - FORTRAN Unit number for service
area treatment efficiencies
9-11 - 13 - FORTRAN unit number for geographic
descriptions
12-14 - 13 - FORTRAN unit number for sewered
stormwater runoff file
15-17 - 13 - FORTRAN unit number for sewage
file (input)
The SEWAGE program output file contains the average daily and
maximum daily sewage flows and pollutant loads estimated to result from a
particular level of water usage by the domestic and commercial sectors.
It is assigned the FORTRAN unit number codes on the unit assignment card.
If this file is not selected for input, the number of planning units on the
service areas card must be coded as zero.
The Sewered Stormwater Runoff File contains the flows and loads of
runoff from the storm entering the sewage system. This file is output by the
SPLIT program. As with the file above, the unit number is assigned on the
Unit Assignment Card. The file can be bypassed if a zero is coded for the
number of watersheds on the Service Areas File.
There are three user-created datasets which must be supplied to the
TREATMENT program.
(a) The Sewer Service Area Assignments file assigns each watershed
and each planning unit to a sewage service area.
(b) The Sewer Service Area Treatment Efficiencies file contains
user-specified pollutant removal efficiencies that represent the
actual or desired level of treatment in each sewage service area.
117
-------
(c) The Geographic Unit Descriptions file provides for each sewage
service area, watershed and planning unit a literal description
of its physical location.
SEWAGE SERVICE AREA ASSIGNMENTS FILE
COL. FORMAT DATA
1-2 12 Record Identification
3-5 13 21 = Watershed No.
22 = Planning Unit No.
6-8 13 Sewage Service Area
Number
9-80 72X Blank
Do not include assignments cards for an input file (wastewater or
stormwater) that will be bypassed in the input operation.
SEWAGE SERVICE AREA TREATMENT EFFICIENCIES FILE
COL. FORMAT DATA
1 II Record Identification '3'
2 IX Blank
3-5 13 Sewage Service Area
Number
6-10 5X Blank
11-23 F13.3 Percent BOD Removed
24-36 F13.3 Percent Nitrogen Removed
37-49 F13.3 Percent Phosphorus
Removed
50-80 3IX Blank
Percentages are coded in decimal form, i.e., 25.5 percent = 0.255, One
record must be provided for each sewage service area.
118
-------
GEOGRAPHIC UNIT DESCRIPTIONS FILE
COL. FORMAT DATA
!~2 12 Card Type
41 = Watersheds
42 = Planning Units
43 = Service Areas
3-5 13 Watershed, Planning
Unit or Service Area
Number
6-10 5X Blank
H-50 10A4 Geographic Description
of Unit Location
51-80 30X Blank
Do not include unit descriptions for an input file (wastewater or stormwater)
that will be bypassed in the input operation.
Output Description
The TREATMENT program produces one tape or disk file and printed
reports of all input and output data.
The tape or disk file output by the TREATMENT program contains the
combined treated flows and loads discharged by each sewage service area
into the estuary. This file contains the combined effluent of the wastewater
and/or stormwater components. Information is directed to the print file in
both list and report formats. The User Control Cards and the user-supplied
input data are listed, record by record, as they are input by TREATMENT.
Additionally, the user-supplied input data is also displayed in report form.
Formated reports of input flows and loads from the wastewater and
stormwater components are produced, as is the report of the combined
treated flows and pollutant loads calculated by the program.
119
-------
POTOMAC ESTUARY MODEL
PURPOSE
The estuary component of the Framework model chain is designed to
model the hydraulics and quality constituents of the Potomac Estuary during
dry weather and storm flow conditions. The estuary model, in its present
form is a result of modifications and additions to the EPA steady state
(19)
Dynamic Estuary Model.
The estuary model utilizes a two-dimensional network of interconnect-
ing junctions and channels shown in Figure 21. The first component, the
hydrodynamic portion, models the tidal condition of the estuary while the
second component develops time-dependent concentration profiles of five
water quality constituents.
CHARACTERISTICS OF OPERATION
Language: FORTRAN IV (G Level)
Region; DYNHYD - 250K
DYNQUA- 210K
PROGRAM DESCRIPTION
The model operations, Figure 22, begins with a simulation of estuary
hydraulics. After the first tidal cycle (25 hours) of computer modeling is
complete, the hydraulic characteristics—head, velocity and flow, are
approximately identical at the end of each tidal cycle under constant inflow
and tidal conditions. This condition is "dynamic steady state" and at this
time water quality modeling commences with or without storm inflows.
Storm conditions can. be modeled any time after dynamic steady state is
achieved. At the end of the storm inflow period, modeling of hydraulics is
continued until dynamic steady state is once again achieved.
120
-------
FIGURE 21
SCHEMATIC OF POTOMAC ESTUARY
FOR FWQA DYNAMIC MODEL
121
-------
Hydraulic simulation must be continued for some time after storm
inflow has ceased. Two points must be reached: first, the system will
return to dynamic steady state; finally, one additional tidal cycle must be
simulated for use by the quality program. Thus, three distinct parts of the
hydraulics simulation are identified;
1. A start-up period;
2. The period of storm effect; and
3. One tidal cycle of dynamic steady state.
Only the last two are preserved for the quality simulation.
Water quality simulation begins after a dynamic steady state has been
reached in the hydraulics solution. It continues through the storm inflow
period, and, frequently, the user will wish to simulate water quality for
many tidal cycles after storm inflow has ended because of the relatively
slow response of this facet of the system. In figure 22, eight such tidal
cycles are shown. The program is now able to repeat the dynamic steady
state hydraulics for as many times as they are requested.
Hydrodynamic Model
The estuary is divided into 115 channels with 114 junctions, as shown in
Figure 21. Each channel is assumed to be straight with a uniform cross-
section and level bottom. Cross-sectional area, velocity, flow and head are
determined, at each junction, every 90 seconds. Determination of these
hydraulic characteristics is done in two steps, therefore two sets of
equations are required. One set of equations determines head, velocity and
cross-sectional area halfway through the 90-second time step and the other
set determines these characteristics at the end of the time step. The first
set of equations obtains rough approximations of the hydraulic characteris-
tics which are then used to obtain more accurate estimates of the hydraulic
characteristics at the end of the 90-second interval. These results in turn
become the input for modeling hydraulic characteristics at the start of the
next time increment at each junction.
122
-------
HYDROLOGY -
End storm inflow
iBegin hydraulics simulation
HYDRAULICS
WATER
QUALITY
Reach dynamic steady state
quality simulation
End transient response
'IjEnd hydraulics simulation
End quality simulation
Repeat last hydraulic cycle
0 ]
1
2
p-
3
1
4
I
5
1
6
i
7
1
8
1
9
— s —
10
' 1
11
I
12
1
13
TIME FROM START OF SIMULATION — TIDAL CYCLES
FIGURE 22. MODEL OPERATIONS
-------
Water Quality Model
The estuary quality model is used to calculate concentrations of five
constituents in the Potomac Estuary. Concentrations are determined at
each of the 114 junctions of the estuary every 30 minutes for five-day BOD,
ammonia, nitrate, dissolved oxygen and chlorophyll A of photosynthetic
phytoplankton.
For each 30-minute time interval, mass balance equations, which take
into account chemical reactions undergone during the time step, are solved
at each junction. The output concentrations of these parameters become
the input, initial concentrations for modeling the next time increment. The
model can be run for as many tidal cycles as desired. At the end of the
storm inflow period, modeling of the quality condition is usually continued
for a few more tidal cycles than the hydraulic modeling because changes in
constituent concentrations is slower than in hydraulic characteristics.
Input Description
The model inputs are described in the data formats and specifications
presented below. The model inputs can be classified in two main categories
- data needs and system control requirements.
The data needs of the hydrodynamic model consist of point source
inflows and withdrawals such as treatment plant discharges and channel
characteristics at each estuary junction. Treatment plant discharges are
determined with the assistance of the output from the TREATMENT
program. The link between fhe sewage treatment data, developed by the
TREATMENT program, is shown in Table 7. Channel characteristics
including length, width, hydraulic radius, initial head and, velocity have been
developed based on field surveys. When simulating storra conditions,, the
model requires storm inflows specified according to the junction where it
occurs and the times at which the storm begins and ends. This input, is
developed with assistance of the output from the runoff program. The link
between the runoff program, is shown in Table 8. That table shows the
estuary segments which receive the flow from the 65 watersheds modeled.
124
-------
TABLE 7, LOCATION OF SEWAGE TREATMENT DISCHARGE POINTS IN THE POTOMAC ESTUARY
ESTUARY SEGMENT
SEWAGE TREATMENT AREA
ACCORDING TO THE TREATMENT PROGRAM
Number Name
78
13
to
in
81
83
85
87
Washington Sailing Marina
Marbury Point
Great Huntin Creek
Piscataway Bay
Gunston Cove
Neabsco Creek
Number Name
2 Arlington County
1 Virginia Upper Potomac
7 Upper Goose Creek and
Loudoun County
9 Rock Creek & Upper Mont. Co.
8 Montgomery County Upper Potomac
10 Lower Montgomery County
11 Anacostia
14 Oxon Run
15 District of Columbia
3 Alexandria & Western Fairfax
13 Lower Prince George's County
4 Southern Fairfax
6 Eastern Prince William County
-------
TABLE 8. LOCATION OF WATERSHED DISCHARGE POINTS IN THE POTOMAC ESTUARY
cr>
.ESTUARY SEGMENT ^Junction)
Number Name
114 Chain Bridge
2 Chain Bridge
5 Georgetown Channel
6 Water Gate
72 Kingman Lane
108 Prince George's Marina
12 Hunter Point
13 Oxon Run Confluence
79 Goose Island
16 Rosier Bluff
80 Fox Ferry
81 Indian Queen Bluff
82 Broad Creek
22 Hatton Point
23 Fort Washington Marina
24 Bryan Point
25 Mount Yemen
84 Mount Vernon Yacht Club
29 Hallowing Point
31 Indian Head
86 Freestone Point
87 Occoquan Bay
87 Occoquan Bay
87 Occoquan Bay
89 Cockpit Point
92 Quantico Creek
38 Possum Point
39 Clifton Point
WATERSHED ACCORDING TO THE RUNOFF MODEL
Number Name
1-34 Potomac River Base Flow
35 Pjjmat Run
36,37 Rock Creek
38 Potomac Direct #6
39 Anacostia Direct, #1
40-42 Anacostia-NW, NE & Paint Branch
43 Fourmile Run
44 Oxon Run
45 Cameron Run
46 Potomac Direct #7
47 Belle Haven
48 Broad Creek
49 Potomac Direct #8
50,51 Piscataway Creek
53 Potomac Direct #9
52 Little Hunting Creek
54 Dogue Creek
55,56 Accotink & Pohick Creeks
57 High Point
60 Marumsco Creek
58 Occoquan below the Dam
59 Kane Creek
61 Neabsco Creek
62 Powell Creek
63 Quantico Creek
64 Little Creek
65 Chopawamsic Creek
-------
The data needs of estuary quality programs consist of hydraulic
characteristics developed in the hydrodynamic program, the chemical and
physical characteristics of the constituents to be modeled, and initial
constituent concentrations in each segment of the estuary. Much of the
data has been collected through field surveys. During simulation of storm
conditions, the concentrations of the constituents entering the estuary need
to be specified.
The system control requirements for both models are similar in nature.
These model inputs specify output formats and define the time step used in
calculations as well as how many tidal cycles should be modeled. In
addition, the hydrodynamics program has inputs which describe the system
of interconnecting channels and junctions as well as the tidal condition. The
estuary quality model also has inputs which define maximum allowable
concentrations of constituents as well as constituent concentrations at the
boundaries of the estuary.
Data formats and specifications for both the hydrodynamic and quality
components follow below.
HYDRODYNAMIC SIMULATION PROGRAM (DYNHYD)
Data Formats and Specifications
In the following description defining the format of the input data deck
required to execute program DYNHYD the symbol:
* denotes that a series of cards as described may be required.
a denotes that the card or series of cards may not be required.
R indicates "right hand justified," i.e., any quantity so described
must appear as far as possible to the right in its data field.
indicates a decimal point must appear in the field.
127
-------
R. indicates that the value is right hand justified but may have a decimal
point to override the programmed decimal point
indicates the repetition of the format on the same card.
indicates the start of a new card.
Card
1
Column
1-80
1-80
1-5R
6-1 OR
11-15R
16-20R
21-25R
26-3 5R
36-45R
46-50R
1-5R
Name
ALPHA(I)
ALPHAtD
NJ
NC
NCYC
NPRT
NOPRT
BELT
TZERO
NETFLW
IPRT
Description
Alphanumeric identifier — printed as
first line of output (up to 80 characters).
I = 1,20 with A4 format.
Alphanumeric identifier — printed as
second line of output (up to 80 characters).
I = 21S40 with A4 format.
Total number of junctions in system.
Total number of channels in system.
Total number of time steps (cycles) to
be completed.
Number of time steps between printouts.
Normally specified to give output at one--
half or hourly frequencies.
Number of junctions
for which output is
printed.
Time interval, in seconds,
used in solution.
Time, in hours, at which
computations begin.
Allows starting point
to be anywhere on tidal
cycle.
Option parameter.
If NETFLW is specified
as any non-zero integer.
Subroutine HYDEX
is called to compute
net flows and summarize
hydraulic parameters.
If NETFLW is specified
as zero, Subroutine
HYDEX is not called.
Printed output begins
at this cycle number
and at each NPRT cycle
thereafter.
128
-------
6-10R
11-15R
IWRTE
KPNCHI
*5
1-5R
6-15R.
16-25R.
26-35R.
Y(J)
AREAS(J)
QIN(J)
36-40R
41-45R.
NCHAN(J,1)
NCHAN(J,2)
Hydraulic parameters
are stored on magnetic
tape or disk beginning
at this cycle number.
Punch interval for restarting.
Magnetic tape is written
at this cycle and at
each KPNCHI cycle
thereafter.
Junction number (read
as dummy variable
JJ to check card sequence).
Initial head specified
at junction J, in feet.
Surface area of junction
J, in square feet.
Specified inflow or
withdrawal at junction
J, in cfs. Inflows must
be assigned negative
values, withdrawals
positive.
Channel number of
any one of the channels
entering junction J.
Channel number of
a second channel (if
it exists) entering junction
J, If only a single channel
element enters the
junction NCHAN(J,2)
and the remaining NCHAN
values must be assigned
a zero value. If exactly
two channels enter
the junction NCHAN(J,3)
and the remaining NCHAN
values must be assigned
a zero value, etc.
129
-------
Card
Column
Name
Description
56-60R
NCHAN(J,5)
Channel number of
the fifth channel (if
it exists) entering junction
J. If less than five
channels enter the
junction (NCHAN(J,5)
must be assigned a
zero value.
Card 5 is repeated
for each junction
in the network
(NJ cards).
*6 1-5R
6-13R.
14-21R.
22-29R.
N
CLEN(N)
B(N)
AREA(N)
30-37R.
38-45R.
46-53R.
54-58R
R(N)
CN(N)
V(N)
NJUNC(N,1)
Channel number (read
as dummy variable
NN to check card sequence).
Length of channel N,
in feet.
Width of channel N5
in feet.
Initial cross-sectional
area of channel N,
in square feet. Must
correspond to the initial
heads specified at the
junctions at the ends
of the channel.
Hydraulic radius of
channel N, in feet,
Taken as the channel
depth.
Manning's roughness
coefficient, dimension!ess.
Initial mean velocity
in channel N, in fps.
The junction number
at one end of channel
N,
130
-------
Card
Column
Name
Description
*7
59.63R
Card 6 is repeated
in the network
(NC cards).
1-5R
6-10R
11-15R
NJUNC(N,2)
JPRT(l)
JPRT(2)
JPRT(2)
The junction number
at the other end of
channel N.
Numbers of those junctions
for which printout is
desired. There will
be NOPRT different
junction numbers, fourteen
to a card. The numbers
need not be in sequence.
I-5R
1-10R.
11-20R
11-30R.
NK
PERIOD
A (2)
Card 1 is repeated as many
times as necessary to include
all junction numbers for
which printout is desired.
Number of coefficients
used to specify the tidal
input.
Period of the input tide,
in hours.
Coefficients for tidal input
at specified junction(s).
Obtained from regression
analysis program, REGAN.
10
71-80R.
1-3R
1-5R
5-10R
A(7)
NJSW
JSW(l)
JSW(Z)
Number of junctions with
hydrograph input.
Junction number for first
hydrograph.
Junction number for second
hydrograph.
etc.
JSW(NJSW)
Junction number for last
hydrograph (maximum 100).
131
-------
Card
12
*13
Column
1-10R.
1-10R.
11-20R.
QE(1)
QE(2)
Description
Time of following set of
hydrograph points (seconds).
Ordinate of first hydrograph
at time TE (cfs).
Ordinate of second hydrograph
at time TE.
14
15
etc.
Cards 12 and 13
will be repeated
for each succeeding
set of hydrograph
points.
1-5
1-80
QE(NJSW)
16
17
1-80
1-5R
6-1 OR
ALPHA(I)
ALPHA (I)
NODYN
NPFACT
Ordinate of last hydrograph
at time TE.
99999 - this card signals
the end of the last set of
hydrographs.
Alphanumeric identifier-
-printed as part of heading
for printout resulting from
HYBEX. I = 41,60 with A4
format.
Alphanumeric identifier
—printed as part of heading
for printout resulting from
HYDEX. I = 61,80 with A4
format.
Number of hydraulic time
steps per quality time step.
Defines the quality time
step as the product of NODYN
and DELT.
Number of tidal periods
to be retained for water
quality simulation.
NOTE: Cards 10, 11 and 12 are read by Subroutine HYDEX but immediately
follow the previous data cards.
132
-------
DYNAMIC WATER QUALITY PROGRAM (DYNQUA)
Data Formats and Specifications - June 1974
In the following description defining the format of the input data deck
required to execute program DYNQUA the symbols
*
a
R
R.
denotes that a series of cards as described may be required.
denotes that the card or series of cards may not be required.
indicates "right hand justified," i.e., any quantity so described must
appear as far as possible to the right of its data field.
indicates a decimal point must appear in the field.
indicates that the value is right hand justified but may have a decimal
point to override the programmed decimal point.
indicates the continuation of the same format on a card.
Indicates the start of a new card.
Card
Column
1-5R
6-1 OR
1-15R
16-ZOR
21-25R
Name
NJ
NC
NSTART
NSTOP
NODYN
Description
Total number of junctions
in system. Identical to
NH in program DYNHYD.
Total number of channels
in system. Identical to
NC in Program DYNHYD.
Cycle number from hydraulic
solution which is the initial
cycle on the hydraulic extract
input tape 3. Identical to
NSTART in DYNHYD (HYDEX).
Cycle number from hydraulic
solution which is the final
cycle on the hydraulic extract
tape 3. Identical to NSTOP
in Subroutine HYDEX.
Number of hydraulic time
steps per quality time step.
Identical to NODYN in Subroutine
HYDEX,.
133
-------
Card Column
26-30R
Blank Card
1-5R
Name
M START
NRSTRT
6-1 OR
INCYC
11-15R
NQCYC
16-20R
Z1-25R
KZOP
KDCOP
26-30R
NTAG
31-40R.
CDIFFK
Description
Starting cycle (on tape 3)
for repeating last segment
of hydraulics.
This card contains variables
no longer used in the program.
Cycle number on input tape
3 (hydraulic extract tape)
at which quality run is to
begin (NSTART < NSTRT
< NSTOP).
Initial quality cycle number.
For first run of a series INCYC
should equal 1. For continuation
or restart runs INCYC should
equal x+1 where x equals
the number of cycles completed
previously.
Total number of quality
cycles to be completed.
NQCYC must include all
cycles previously completed,
i.e., NQCYC equals INCYC
plus the additional cycles
to be completed in the current
run.
Control option for calling
Subroutines ZONES. KZOP
must equal 1 to call ZONES
or 2 to bypass ZONES.
Control option for printout
of depletion correction
message. KDCOP must
equal 1 for printout or 2
to delete printout of depletion
correction message.
Counter which is reset to
zero at the completion of
each full tidal cycle. NTAG
varies between zero and
NSPEC where NSPEC is
the number of quality cycles
per tidal cycle.
Constant for computing
diffusion coefficient.
134
-------
Card
Column
1-5R
Name
EPRT
6-10R
NQPRT
11-15R
16-20R
NEXTPR
INTBIG
Z1-Z5R
IWRITE
26-30R
31-35R
NEXTWR
IWRINT
5 1-80
1-80
ALPHA(I)
ALPHA (I)
Description
Initial print cycle (IPRT
must be > INCYC). Printout
begins for the first time
at cycle IPRT and continues
for one full tidal cycle at
intervals of NQPRT cycles
(time steps).
Number of quality cycles
(time steps) between printouts.
NQPRT normally is such
that printout is obtained
at hourly or two-hour intervals.
Quality cycle number at which printout
begins for second time and continues
at NQPRT intervals for a full tidal cycle.
Interval, in quality cycles
(time steps), between the
start of printouts over a
full tidal cycle. NEXTPR
is increased by INTBIG at
the completion of each
full tidal cycle of output.
Cycle number at which
storage of quality data on
tape or disk begins for the
first time. Data for each
time step over a full tidal
cycle is passed to Subroutine
Qualex.
Cycle number at which
storage of quality data on
tape or disk begins for the
second time.
Interval, in quality cycles
(time steps), between the
storage of data on tape
or disk. NEXTWR is increased
by IWRINT at the completion
of storing data for a full
tidal cycle. Quality summaries
are obtained at IWRINT
intervals.
Alphanumeric identifier
for quality run— printed
as heading for output (1=41,60
with A4 format).
Alphanumeric identifier
for quality run— printed
as heading for output (1=61,80
with A4 format).
135
-------
Card Column
7 1-5R
8
1-5R
Name
NUMCON
NCONDK(l)
6-1 OR
NCONOX(l)
Etc.
1-5
NR
10
1-10
11-20
21-30
31-40
41-50
51-60
NFJ(I)
NLJ(I)
PHOTT(I)
RESS(I)
DEPTHH(I)
BENTT(I)
Description
Number of quality constituents
considered in the (1
-------
Card
Column
Name
Description
Cards 11 and 12 should be
omitted if NCONDK(1)=0.
1-10
DECAY(l)
11-20R
REOXK(l)
21-30
31-40R.
41-50R.
51-60R.
61-70R
71-80R.
RORDER(l)
TEMP(l)
BACKC(l)
IREOXK(l)
THETA(l)
Decay coefficient (base
e, per day) applied to the
nonconservative constituent
assigned to NCONDK(l),i.e.,
to the first nonconservative
constituent.
Reoxygenation coefficient
(base e, per day) applied
to the DO constituent (if
any) assigned to NCONOX
(1).
Blank
= 1., use first order equation.
=2.} use second order equation.
Temperature (base 20 )
for correction of rate constants.
Background concentration
for this constituent; computed
value will not be less than
BACKC.
=1, Reoxygenation will occur
for this constituent.
=0, Reoxygenation will not
occur for this constituent.
Water temperature ( C).
Etc.
*12 1-80
ALPHA(I)
13
1-10R.
Maximum 5 constituents.
Alphanumeric identifier,
one card for each constituent
(1=121, NALPHA where
NALPHA = NUMCON*20).
Concentration limit for
first constituent. Run is
aborted is concentration
exceeds C LIMIT.
137
-------
Card Column
Name
Description
11-ZOR.
CLIMIT(Z)
Concentration limit for
second constituent.
14
41-50R.
1-5R
CLIMIT(5)
NUNITS
15
1-3R
4-7R
9-HR
1Z-15R
16-ZOR.
21-28R.
29-33R.
34-41R.
JDIVl(l)
JDIVZ(l)
JRETl(l)
JRET2(1)
RETFAC(1,1)
CONST(1,1)
RETFAC(1,Z)
CONST(1,Z)
Concentration limit for
fifth constituent.
The number of units for
which waste water return
factors are applied. A unit
consists of two junctions
at which diversions occur
and two junctions at which
the waste water from those
diversions is returned. The
same factor is applied to
both junctions in each pair.
If NUNITS-0, cards 13 should
be omitted.
The junction number of
the first diversion in unit
The junction number of
second diversion in unit
1.
The junction number of
the first return flow in unit
1. JRETl(l) is paired with
JDIVl(l).
The junction number of
the second return flow in
unit 1. JRETZ(l) is paired
with JDIVZ(l).
Return factor for unit 1
and constituent 1.
Constant applied to junction
in unit 1 for constituent 1.
Return factor for unit 1
and constituent 2.
Constant for unit 1 and
constituent 2.
138
-------
Card
*16
17
Column
68-72R.
73-80R.
Etc.
1-5R
6-15R.
16-25R.
26-35R.
36-45R.
46-55R.
Etc.
1-5R.
Name
RETFAC(1S5)
CONST(1,5)
CBASE(J,1)
C(J,2)
CBASE(J,2)
NGROUP(l)
*18
1-5R.
FACTR(1,1)
6-10R
NJSTRT(191)
Description
Return factor for unit 1
and constituent 5.
Constant for unit 1 and
constituent 5.
NUITS times.
Junction number^ Read
as dummy variable JJ to
check card sequence.
Field not used,
Initial concentration assigned
to junction J for the first
constituent.
The specified concentration
of the first constituent
in. the base flow discharge
QUINST(J) at junction J.
Initial concentration assigned
to junction J for the second
constituent (if more than
one constituent is considered).
The specified concentration
of the second constituent
in the base flow discharge
QINST(J).
The number of groups (up
to 10) of junction numbers
for which it is desired to
increment the initial concentrations
of the first constituent
which were previously read
as input, There is no limit
(up to NJ) to the number
of junctions comprising
a group but the numbers
must be consecutive.
Multiplication factor to
be applied to the Initial
concentration of the first
constituent at those junctions
in the first group. This
card will not be required
if NGRGUP(1)=Q.
The first (lowest) junction
number in the sequence
of junctions comprising
the first group for first
constituent.
139
-------
Card
Column
11-15R
Name
NJSTOP(131)
19
Etc.
1-5R
KNOP(l)
6-1 OR
KBOP(2)
ZO
21
Etc.
1-5R
1-10R.
NSPEC
11-20R.
CIN(1,2)
Description
The final (highest) junction
number in the sequence
of junctions comprising
the first group for the first
constituent.
Control option for specifying
concentration of first constituent
at boundary. If boundary
concentration is constant
over full tidal cycle KBOP(1) = 1,
if variable over tidal cycle
KBOP(1)=Z.
Control option for specifying
concentration of second
constituent at boundary,
KBOP(2)=1 for constant
boundary, or 2 for variable
boundary.
The number of quality time
steps per tidal cycle.
The boundary concentration
specified for the first constituent
for the initial time step.
If KBOP(1)=1 then CIN(1,1)
is the constant boundary
concentration and no additional
specification is required
for the first constituent.
The boundary concentration
specified for the first constituent
for the second time step
if KBOP(1)=2.
61-70R
CIN(1,7)
The boundary concentration
specified for the first constituent
for the seventh time step.
Etc.
Card Zl is repeated as necessary
to specify all NSPEC boundary
concentrations for the first
constituent.
140
-------
Card
Column
Name
Description
22
*23
1-5R
1-5R
6-1 OR
NOPRT
JPRT(l)
JPRT(2)
The total number of junctions
for which printout is desired.
Junction number for which
printout is desired.
Junction number for which
printout is desired.
24
25
Etc.
1-3R
1-5R
6-10R
NJSW
JSW(l)
JSW(Z)
Number of junctions with
pollutograph input.
Junction number for first
pollutograph.
Junction number for second
pollutograph.
26
27
Etc.
1-10R.
1-10R.
11-20R.
JSW(NJSW)
TE
CSPEC1
CSPEC1
Junction number for last
pollutograph (maximum
100).
Time of following set of
pollutograph points (hrs.).
Ordinate of pollutograph
for first constituent, first
junction at time TE(tngl).
Ordinate of pollutograph
for first constituent, second
junction at time TE(mgl).
Etc.
CSPEC1
Ordinate of pollutograph
for first constituent, last
junction at time TE(rngl).
141
-------
Data Sources
The source of data for the estuary model has been a series of studies and
, . A 1A 21, 22, 23, 24, 25, and 26
reports done over the last 10 years.
Theories and Algorithms
The estuary mode! is a real time system incorporating hydraulic and quality
components. The hydraulic solution describes tidal movement, while the quality
solution considers the basic transport mechanisms of advection and dispersion as
well as the pertinent sources and sinks of each constituent. The estuary model
can concurrently simulate five different constituents. They may be either
conservative or nonconservative and may be interrelated in any mathematical
linkage. A detailed description of the theory behind this model is available from
19
EPA , while the sequence of calculations in the algorithm is presented below.
Estuary Hydrodynamic Model
A summary of the mathematical analyses and constants is presented in
Appendix B. Equations 1 through 11 are solved, as used in the model? for each
ninety-second time step for each junction of the estuary. The solutions of these
equations for the first time step are used as input data for the subsequent time
step. The equations are solved in two steps during the time step to aid in
obtaining a stable solution and to shorten the number of time steps required to
reach a steady state estuary flow condition; that is, until the start of the next
tidal cycle at each junction are identical to the heads of the preceding tidal
cycle at the corresponding junctions.
142
-------
In the first half of the time step the "a" equations are solved (that is la ,
2a , etc.) while in the second half of the time the "b" equations are solved.
Essentially, the solutions of the "a" equations provide a rough approximation of
the junction heads and channel velocities which are then used in the "b" equations
to obtain more accurate estimates of the junction heads and channel velocities
required for the Estuary Quality Model. Equations 12 and 13 are applied only
in the latter half of the time step. A description of the solution of these
equations for a pair of adjacent junctions and their channels is now discussed.
A friction coefficient using Eq. 2a is calculated by means of the Chezy-
Manning relationship with a value for the hydraulic radius of the channel
connecting the adjacent junctions calculated from Eq. la using the vertical
cross-section of the channel at the start of the time step, Eq. 3a is used to
calculate the change in head between adjacent junctions at the start of the time
step. This result is used by Eq. 4a to determine the change in channel cross-
section area connecting adjacent junctions at the start of the time step. A flow
rate is calculated for each channel leaving the junction by Eq. 5a . Equation
6a is used to sum the net flows out of a junction including withdrawals for
water supply and irrigation, water additions from streams tributary to the
estuary and from waste treatment facility flows into the estuary and storm water
flows into the estuary during storms. Equation 7a then is used to calculate a
new head for the junction as a result of these flows occurring during the first
half of the time step.
Equation 7a together with the value of the head of a junction from the
end of the previous time step, an average change in head along the channel
between adjacent junctions for the first half of the time step, is calculated by
Eq. 8a . This now enables Eq. 9a to calculate an average cross-section area of
the channel for the middle of the time step. Using the channel cross-section
area changes obtained from Eq. 4a and the junction head changes obtained from
Eq. 8a , and Eq. lOa, one can calculate an average velocity gradient for the first
half of the time step along a channel connecting adjacent junctions. This value
of velocity gradient together with the channel friction coefficient of Eq. 2a, the
value of channel velocity at the start of the time step, a. channel head gradient
obtained from Eq. 3a, and input data on the length of the channel, is used in Eq.
Ha to determine channel velocity between adjacent junctions.
143
-------
In a similar manner Eq. Ib through lib are solved with one
exception; at the most seaward junction the head at the end of the time step
is calculated from given data representing the tidal boundary condition. At
this junction Eq. 12 and 13 are used. The varying head operating at the
seaward junction of the estuary provides the driving force seen at the
remaining junctions of the estuary as a variation in water level.
Estuary Water Quality Model
The Estuary Quality Model is used to calculate the concentration of
five constituents in the Potomac Estuary. For the 114 junctions of the
Potomac Estuary concentrations are calculated each half hour. Thus for
each tidal day, (25 hours), 28,500 concentrations are calculated. The five
constituents are BOD dissolved oxygen, ammonia, nitrate, and chlorophyll A
of photosynthetic phytoplankton.
The interaction of these constituents is shown in Figure 23, for one
junction and one time step. The BOD,- load in the junction reacts during the
time step with the dissolved oxygen in the junction to result in the exertion
of an ultimate carbonaceous oxygen demand. Similarly the ammonia (NHL)
load in the junction reacts during the time step with the dissolved oxygen in
the junction to result in the exertion of an ultimate nitrogenous oxygen
demand. The sum of the ultimate carbonaceous and nitrogenous oxygen
demand are represented in the figure as ultimate O9 demand.
Lt
The ammonia is oxidized in the estuary in a nitrification process to
form nitrate. The chemical equations are shown in Appendix C, Eq. 14 .
The nitrate is incorporated into photosynthetic phytoplankton in the
proportion, 93 micrograms of chlorophyll A per milligram of nitrate as N.
144
-------
Chlorophyll "a" of Phytoplanton
Benthic Oxygen Demand
FIGURE 23. WATER QUALITY MODEL BASIS FOR COMPUTATICNS
145
-------
The mass of chlorophyll A, which is a measure of the photbsynthetic
phytoplankton in the junction, adds dissolved oxygen through the process of
photosynthesis to the junction at the rate of 0.012 milligrams of O, per hour
per microgram of chlorophyll A. This reaction, however, takes place during
daytime and only in the euphotic zone. The depth was set at two feet and
the daytime portion of the diurnal cycle was set at 1Z hours in the model for
all junctions.
To account for respiration, the mass of chlorophyll A is used to remove
dissolved oxygen from the junction at the rate of between 0.0006 and 0.0008
milligrams of O-, per hour per microgram of chlorophyll A. This reaction
LJ
takes place in the model throughout the diurnal cycle in the full depth of
estuary for all junctions.
Oxygen is added through the air-water interface to the junction by
aeration. This effect is modeled using the O'Connor-Dobbins multiple
regression equation to calculate the reaeration coefficient. The reaeration
coefficient equation is shown in Appendix C, as Eq. 1Z . The amount of
oxygen added by the model to the junction during the time step is
proportional to the dissolved oxygen saturation deficit.
Dissolved oxygen is removed from the junction by the consumption of
oxygen by the benthos based on a constant for all junctions of 1 gram of O7
h
per square meter per day.
The interaction of the constituents take place at varying rates in first
order reactions; the equation of which is shown in Appendix D, Eq. Zl .
The values of the reaction rates are shown in the constants section of
Appendix D. The half-life of ammonia in a junction due to its reaction with
oxygen is 3,01 days. The half-life of BODg due to its reaction with oxygen in
a junction is 4.08 days. The half-life of chlorophyll A because of predation in
the junction is 7.3Z days. The half-life of nitrate in a junction due to uptake
146
-------
by photosynthetic phytoplankton is 7.69 days. All of these half-lives are
based on a water temperature of 20 C; adjustment for water temperature
other than 20 C is performed by Eq. 22 of Appendix D.
The concentrations of the five constituents are calculated for each
thirty-minute time step in the Estuary Quality Model in a manner which is
summarized in the thirty equations of Appendix D. These equations repre-
sent the calculations of the five constituents concentrations at one junction
for one time step.
The concentration of each constituent in a junction for each time step
is calculated by Eq. 1 based on the mass of the constituent in the junction
and the volume of the junction at the end of the half-hour time step. The
volume of the junction at the end of the time step is calculated by Eq. 2
using data from the Estuary Hydrodynamic Model. The mass of the
constituent at the end of the time step is calculated for dissolved oxygen by
Eq. 3 , for ammonia by Eq. 19, and for BOD,- by Eq. 23 , for chlorophyll A
by Eq. 27 , and for nitrate by Eq. 29 . These constituent masses in a
junction at the end of the time step are based on physical, chemical, and
biological processes in addition to being based on the initial mass of the
constituent in the junction adjusted for an addition of mass from stormwater
flows and treatment plant flows by Eq. 4 .
The physical processes primarily consist of the advection of the
constituents in the direction of the flow simulated for each junction by the
Estuary Hydrodynamic Model; and diffusion of the constituents toward the
junction of lower constituent concentration. The mass of each constituent
advected between adjacent junctions during a time step in the direction of
flow is calculated by Eq. 5 utilizing the quarter-point concentration
defined and calculated by Eq. 6 . The mass of each constituent transferred
by diffusion between adjacent junctions during a time step in the direction
from higher to lower concentration is calculated by Eq. 7 using a diffusion
coeffient in the channel connecting the adjacent junctions calculated by Eq.
8 . Equation 8 , however, requires the calculation of hydraulic radius by
application of Eq. 9 which is based on the results of the Estuary
Hydrodynamic Model.
147
-------
In addition to the advection and diffusion, a third physical process is
simulated by the Estuary Quality Model, that is aeration or reaeration. The
mass of molecular oxygen in a junction at the end of a time step, as
previously mentioned, is calculated by Eq. 3 . One term of this equation
represents the mass of molecular oxygen added to the junction by aeration
during the time step. This term is calculated by Eq. 10 based on the
dissolved oxygen saturation deficit at the start of the time step and the
ratio of the mass of oxygen deficient in the junction at the start of the time
step. This ratio is calculated by Eq. 11 based on a reaeration coefficient
determined using the O'Connor-Dobbins relationship presented as Eq. 12
which is corrected for temperature by Eq. 13 .
The chemical and biological processes are reflected in the model as
the remaining five terms of Eq. 3 . The first of these terms representing
the mass of molecular oxygen removed from a junction, by reaction with
ammonia, is calculated by Eq. 14 . This equation converts the mass of
ammonia as N removed from the junction during the time step by reaction
with molecular oxygen to the mass of molecular oxygen removed from the
junction during the time step by reaction with ammonia as N. Eq. 20 is
required to determine the mass of ammonia reacting with oxygen in the
junction during the time step based on a decay rate calculated by Eq. 21 .
Eq. 22 is also used to correct the decay rate constant for temperature.
The decay constant is presented in the "CONSTANTS" section of Appendix
D.
The second of the five chemical-biological terms of Eq. 3 represents
the mass of molecular oxygen removed during the time step from the
junction by reaction with ultimate biochemical oxygen demanding sub-
stances. Eq. 24 is used for this calculation based on the mass of five-day
biochemical oxygen demand exerted during the time step calculated by Eq.
25 and converted to oxygen demanding substances on an ultimate basis by
148
-------
application of Eq. 26 and by application of the constant, Ro> which states
that one milligram of dissolved oxygen is used in the reaction with one
milligram of ultimate biochemical oxygen demanding substances. Equation
25 also requires the use of Eq. 21 to calculate the reaction rate between
the oxygen demanding substances and the molecular oxygen in the junction.
The third and fourth of the five chemical-biological terms of Eq. 3
are used to represent the mass of molecular oxygen removed from the
junction by respiration and added to the junction by photosynthesis during
the time step. Eq. 15 is used to calculate the respiration term and Eq. 16
is used to calculate the photosynthesis terms. Both of these equations
require an input representing the mass of chlorophyll A in the junction
calculated by Eq. 27 at the end of the previous time step. Equation 27
is used to sum the terms changing the chlorophyll A levels of a junction from
the start of a time step in the same manner that Eq. 3 sums the terms
changing the dissolved oxygen level of a junction from the start of a time
step. Thus Eq. 27 utilizes a term for chlorophyll A advection, calculated
by Eq. 5 ; diffusion, calculated by Eq. 6 and 7 ; and decay, calculated by
Eq. 28 . However, an additional term is used to represent the addition of
Chlorophyll A which itself is proportional, in the model, to the concentration
of photosynthetic phytoplankton. The relation between chlorophyll A and
nitrate is shown in the "CONSTANTS" section of Appendix D. To solve the
photosynthesis term of Eq. 3 by use of Eq. 16 also requires the solution of
Eq. 17 to establish the volume of the euphotic zone.
The last term of Eq. 3 is used to represent the mass of molecular
oxygen removed from the junction by reaction with the benthos of the
junction during the time step. Eq. 18 is used to calculate this oxygen
demand based on a benthic oxygen demand of 1 gram of molecular oxygen
per square meter per day.
At this time Eq. 3 can be solved for the dissolved oxygen concentra-
tion in the junction at the end of the time step. Similarly, Eq. 19 can be
solved for the ammonia concentration at the junction; Eq. 23 can be solved
for the five day BOD concentration at simulation temperature; Eq. 27 can
be solved for the chorophyll A concentration; and Eq. 29 can be solved for
the nitrate concentration at the end of the time step.
149
-------
These equations are solved for each junction and channel, until the
concentration at each junction throughout one tidal cycle are repeated
during the subsequent tidal cycle.
Model Outputs
Sample outputs for the components of the estuary model are found in
Appendix C and D. In addition to what is presented in these appendices,
much of the input data are printed out for informational purposes.
Estuary hydrodynamic model outputs include:
(a) Description of the hydraulic system in terms of head, velocity
and flow every 90-seconds.
(b) Channel and junction physical characteristics.
(c) Maximum, minimum and average head and when it occurs.
(d) Tidal range in each junction.
Estuary water quality model outputs include:
(a) Description of hydraulic input, and mean tide.
(b) Concentrations of each water quality parameter at each junction
every 30 minutes.
(c) Average, minimum and maximum concentration for each water
quality parameter at each junction.
(d) All input data, coefficients and constants of all equations used
in the model.
Model Availability
The most recent version of the Potomac Estuary Model may be
obtained from the:
Annapolis Field Office
U.S.E.P.A. - Region HI
Annapolis Science Center
Annapolis, Maryland 21801
150
-------
REFERENCES
1. Spooner, C. S.; Graham, P. H.; Promise, J.; and Febiger, W.
Technical Summary of the Framework Water Resources Planning
Model. Washington, D.C.: Metropolitan Washington Council
of Governments, 1974.
2. Metropolitan Washington Council of Governments, Report on the Use
of Regional Plumbing Codes to Effect Water_Conservation.
Washington, B.C. June 1973.
3. U.S. Environmental Protection Agency. "State and Local Assistance -
40 CFR 35, Subpart E, Appendix A, Cost Effectiveness Analysis,
Final Regulations." Federal Register. 39(29):5268-5270.
February 11, 1974.
4. Spooner, Charles S.; Promise, John; and Graham, Philip H. A
Demonstration of Areawide Water Resources Planning. Wash-
ington, D.C.: Metropolitan Washington Council of Governments,
1974.
5. Federal Water Pollution Control Acts of 1972. U.S. Code,
Vol. 33 (1972).
6. Peat, Marwick, Mitchell, and Co. "Empiric" Activity Allocation
Model: Application to the Washington Metropolitan Region.
Washington, D.C. : Metropolitan Washington Council of Govern-
ments, 1972.
7- Hittman Associates, Inc. MAIN I, A System of Computerized Models for
Calculating and Evaluating Municipal Water Requirements.
Vol. I: Development of the MAIN I System Washington, D.C.:
Office of Water Resources Research, U.S. Department of the
Interior, 1968.
8. Hittman Associates, Inc. MAIN I, A System of Computerized Models
for Calculating and Evaluating Municipal Water Requirements.
Vol. II: Description of the MAIN I System and Library of Water
Usage Parameters. Washington, D.C. : Office of Water Resources
Research, U.S. Department of the Interior, 1968.
9. Hittman Associates, Inc. MAIN I, A System of Computerized Models
for_Calcul3.ting and Evaluating Municipal Water Requirements.
Addendum to Final Report. Washington, D.C.: Office of Water
Resources Research, U.S. Department of the Interior, 1969.
10. Hittman Associates, Inc. Forecasting Municipal Water Requirements.
Vol. I: The MAIN II System. Washington, D.C.s Office of Water
Resources Research, U.S. Department of the Interior, 1969.
151
-------
- 2 -
11. Howe, Charles W., and Linaweaver, F. P. Jr. The Impact of Price
on Residential Water Demand and its Relation to System Design
and Price Structure. Washington, D.C.: Resources for-the
Future, Inc., 1967.
12. Howe, Charles W., et. .ajL. Future Water Demands — The Impacts of
Technological Change, Public Policies, and Changing Market
Conditions on Water Use Patterns of Selected Sectors of the
United States Economy; 1970-1990. Washington, D.C. : Resources
for the Future, Inc., 1971
13. Linaweaver, F. P. Residential Water Use. Report II: Phase Two.
Department of Sanitary Engineering and Water Resources, the
Johns Hopkins University. Washington, D.C.: Federal Housing
Administration, 1965.
14. Linaweaver, F. P. Residential Water Use. Report I: Phase Two.
Department of Sanitary Engineering and Water Resources, the
Johns Hopkins University. Washington, D.C.: Federal Housing
Administration, 1964.
15. Washington Suburban Sanitary Commission. Water and Sewer Rates.
Hyattsville, Maryland, 1971.
16. Wolff, Jerome B.; Linaweaver, F. P.; and Geyer, John C. Commercial
Water Use. Department of Environmental Engineering Science,
the Johns Hopkins University. Baltimore County, Maryland:
Baltimore County Department of Public Works, 1966.
17. Graham, P.; Costello, L.; and Matton, . "Estimation of Impervious-
ness and Specific Curb Length for Forecasting Stormwater•Quality
and Quantity." Journal of Water Pollution Control Federation,
(April 1974) ,
18. Metcalf and Eddy. Stormwater Management Model, Final Report.
Washington, D..C. : Environmental Protection Agency, 1971.
19. Feigner, K. and Harris, Howard S. Documentation Report, Federal
Water Quality Administration Dynamic Estuary Model. Washington,
D.C.: Federal Water Quality Administration, U.S. Department
of the Interior, 1970.
20. Hittman Associates, Inc. Forecasting Municipal_Water Requirements.
Vol. II: The Main II System Users Manual. Washington, D.C.:
Office of Water Resources Research, U.S. Department of the
Interior, 1969.
21. Clark, L. J. and Kenneth D. Feigner, "Mathematical Model Studies
of Water Quality in the Potomac Estuary," Annapolis Field
Office, Region III, EPA, March 1972.
22. Jaworski, N. A.; Clark, L. J.; and Feigner, L. P. A Water Resource-
Water Supply Study of the Potomac Estuary. Washington, D.C.:
Chesapeake Technical Support Laboratory, U.S. Environmental
Protection Agency, Region III, 1971.
152
-------
- 3 -
23. Jaworski, N. A. and Clark, L. J. Physical Data_Pqtomac River Tidal
System Including Mathematical Model Segmentation. Washington,
B.C.: Chesapeake Technical Support Laboratory, U.S. Environ-
mental Protection Agency, 1970.
24. Chesapeake Technical Support Laboratory. Wate_r Duality Survey of
the Potomac Estuary — 1965-1966 Data Report. U.S. Environ-
mental Protection Agency, N.D.
25. Chesapeake Technical Support Laboratory.
the Potomac Estuary — 1967 Data Report. U.S. Environmental
Protection Agency, N.D.
26. Chesapeake Technical Support Laboratory. Water Quality Survey of
the Potomac Estuary — 1968 Data Report. U.S. Environmental
Protection Agency, N.D.
27- Jaworski, N. A. and Clark, L. J. Nutrient Transport and^ Dissolved
Oxygen Budget Studies in the Potomac Estuary; Technical
Report 37 , U.S. Environmental Protection Agency.
28. Lothrop, George T. and Hamburg, John R. "An Opportunity Access-
ibility Model for Allocating Regional Growth." Journal of the
American Institute of : Planners (May 1965) , pp. 95-103.
29. Dickey, John W.j Leone, Phillip A.,- and Scharte, Allan R. "Use of
TOPAZ for Generating Alternate Land Use Schemes." Highway
Research Record. Number 422, (1973), pp. 39-53.
30. Goldner, William, Pro j active Land Use Model (PLUM) ; A Model for
the Spatial Allocation of Activities and Land Uses in a_Metro-
politan Region. BATSC Technical Report 219. Berkeley: Bay
Area Transportation Study Commission, 1968.
31. Comprehensive Planning Organization. Interactive Population Employ-
ment Forecasting Model, Technical Users' Manual. San Diego,
California, 1974.
32. Water Resources Engineers. Modifications to the Potomac Estuary
Model. Springfield, Virginia: 1974.
153
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APPENDIX A
ALTERNATE MODELS FOR COMMUNITY DEVELOPMENT COMPONENT
Urban land use and community development models have received
much attention in the literature and in practical application in recent years.
These computer simulation models offer data processing and empirical
testing capabilities to evaluate theories regarding the location of activities
in a region. The models considered in this paper are, in general, economic
and/or population allocation models.
The Opportunity-Accessibility model was developed by Lothrop and
7 p
Hamburg . This is a model of urban growth which relies heavily on
transportation concepts and makes use of a modification of Morton
Schneider's intervening opportunity model.
Topaz, a technique for the optimum placement of activities in zones,
was developed for use in Melbourne, Australia by Brotchie, Toakley, and
Sharpe. An application to Blacksburg, Virginia by Dickey, Leone and
29
Schwarte is considered here.
o /
Plum, the projective land use model, was developed by Goldner > and
has been applied to studies in San Francisco 1968, San Diego 197Z, and is
curreniiy being used in Baltimore. Plum is a successor to the Lowry Model,
developed by Ira Lowry for the Rand Corporation in 1964.
IPEF73 Interactive Population Employment Forecasting Model was
developed by the Comprehensive Planning Organization of the San Diego
Region although it has been used by a number of agencies in other areas of
the Country.
154
-------
Z8
OPPORTUNITY ACCESSIBILITY MODEL
The purpose of the model is to allocate future estimates of activities
(trip distributions) to small geographic areas, and forecast future distribu-
tion of people and trip making. Essentially, opportunities accessibility
involves two concepts. One, asserts that the tripmaker will have
alternatives for satisfying his trip purpose. The second, asserts that there is
a finite probability that tlie tripmaker will stop at any of the alternatvies.
This probability increases at each successfully encountered alternative, with
each prior alternative not taken.
The model requires a measure of opportunities in each zone, and a
measure of zone to zone travel time which serves as a basis for ranking
zones. The probability of a trip terminating in any zone can then be
calculated.
The model can be used to examine regional growth that might result
from certain policies with respect to land development. For example? given
a prescribed density, the model could be used to examine development that
might occur.
. . . , lo -l(o+oj) v
Aj = A(e -e J )
Where:
Aj = the amount of activity to be allocated to zone j
A = the aggregate amount of activity to be allocated.
1 = probability of a unit of activity being sited at a given opportunity.
o = the opportunities for siting a limit of activity rank ordered by access
value and preceding zone j.
oj =• the opportunities in zone i.
155
-------
Criteria for Model Design
1. The model based on a theoretical statement of the mechanisms of land
development. Although it need not simulate individual decisions within
the land market, it should give results which correspond to the real
world.
2. The model should be incremental and recursive. Ideally, data on past
land use and transportation systems should be used to simulate the
present development pattern. If this ability is lacking increments of
growth should be layered on the present structure.
3. The model should be relatively simple. A finite number of land uses
and a minimum number of sub-sets of households should be required to
minimize the difficulties of data acquisition and handling.
4. Ideally, the calculation of activity density should be contained within
the model. Alternately, the model should readily accept exogenous
densities.
5. The model should accept alternatives measures or indices of access.
This condition provides the flexibility required for situations in which
one measure is particularly appropriate to a given activity type with a
different measure of access. This condition provides the flexibility
required for situations in which one measure is particularly appropriate
to a given activity type while a different measure of access is best
suited to other activity types.
6. The model should be able to accept data from redevelopment, urban
renewal, or new-town plans. This operation can be handled as a
preliminary updating (internal to the model) of the land use and
activity base or it can be done within the main frame of the model.
7. The model should be capable of being claibrated. For example, it
should be possible to simulate past growth, or at least to calibrate the
model parameters using the present structure.
156
-------
8. Provision for sensitivity analysis should be considered in the design of
the model. It is vital to be able to evaluate the effect of unit changes
in a given parameter on all facets of the allocation produced by the
model.
9. The output of the model should permit easy and rapid comprehension
of allocation results, with particular emphasis on a simple graphic
description of settlement patterns. This graphic output is particularly
important for the comprehension and evaluation of alternative model
inputs. Tabular outputs which can be used in calibration, sensitivity
analysis, and allocation evaluation are also an obvious requirement.
10. Output from the model should be directly usable in existing traffic
assignment procedures to minimize the difficulty and time involved in
applying the results of the operation of the model.
157
-------
29
TOPAZ
Technique for Optimum Placement of Activities in Zones
Initially developed for use in Melbourne, Australia. The intent is to
use a gravity model to generate land use allocation schemes that are optimal
according to a set of objectives.
Capitol costs for water, sewerage, local streets, electricity, and
individual building units are compiled for each zone and used in conjunction
with travel costs and land use information to devise overall cost minus
benefit values for the schemes.
A prediction was made of how much capital costs would be needed by
1985 for high and low density residential land and industrial land. Topaz was
then used to allocate the needed land use areas so as to minimize public
services and travel costs. Solutions were constrained so that areas would
not be developed over their capacity.
The objective of Topaz is to minimize the combination of overall
travel costs and capital costs minus benefits. Travel between zones and
travel costs are determined with a gravity model. Capital costs and benefits
are input values. The formulation of Topaz can be presented as follows:
MINZ = E E Cij Xij + E Kjk E PRi(Xij + Eij)EATi(Xlk + Eik) ~Tjk2
i j j k L E EATi(Xin+Ein) 1
EXij = Ai, All i
EXij = Bj, Allj
EAi = EBj
158
-------
Topaz has been found to have an extremely fast computation time.
For a problem with 976 variables computing times on the IBM 360/65
Computer were about 1 minute.
The notation used is as follows:
Xij = amount of activity i allocated to zone j, acres;
Eij = existing amount of activity i in zone j, acres;
Ai = future amount of activity i to be allocated, acres;
Bj = area available for development in zone j, acres;
Csij = unit establishments benefits or capital costs for services for activity
i in zone j, dollars/acre;
Cij = total establishment costs-benefits for locating activity i in zone
j, dollars/acre;
PRi - daily vehicular trip production rate for activity i, vehicles/day/acre;
ATi = daily vehicular trip attraction ratefor activity i, vehicles/day/acre;
S2 = speed over link 1, mph;;
L2 = length of link 1, miles;
Pjk = set of links on the minimum time path from zone j to kj
Tjk = minimum highway travel time from zone j to k, min;
Mjk = distance over minimum highway travel time path from zone j to
k, miles;
d = number of repetitions of daily trips in a year;
y = length of planning horizon, years;
pm_ - vehicular cost to travel over link 1, dollars/mile;
z = sum total of all travel costs and establishment cost-benefits, dollars;
z = value of the objective function of the linear "transportation problem,"
dollars; and
Kjk = cost over the planning period for a repetitive trip from zone j to k,
dollars/daily trip.
159
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PLUM
Projection Land Use Model
A successor to the Lowry Model. It was implemented to provide the
land use allocations and small zone forecasts of population, dwelling units,
and employment.
The model is concerned with a set of tripmakers and their work to
home or home to work tripmaking behavior.
Given a particular origin the model is used to show that the trips to
any given destination will be proportional to the difficulty of reaching the
destination and the degree to which that particular destination is capable of
satisfying the trip purpose. The difficulty of reaching the destination is
expressed in terms of travel time or cost. The attractiveness or
opportunities located at a destination is used to measure the degree to which
a particular destination can satisfy the trip purpose.
The allocation function has two components. The first component is
the probability of making a trip of a particular length for a given purpose.
The second component is the measure of attractiveness of the destination.
The probability of making a trip of length T is inversely proportional to
an exponential function of the negative reciprocal of the length. This
function is applied in the allocation of residences to concentric rings around
each given origin zone. The probability of making a trip is calculated, then
divided among the zones.
Based on this procedure, a matrix of trip probabilities for each zone to
each other zone is calculated. With the use of a scale factor these
probabilities are applied to the zonal employment to produce the distribution
of residences,
160
-------
To run PLUM} with a zone size up to about 350, a 360 model 40 or
better with Z56K bytes of storage is necessary. A small zone system could
be run on a 128K byte machine with some reprogramming and overlays,
however, only the layer computers have been used.
161
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IPIF73 INTERACTIVE POPULATION EMPLOYMENT FORECASTING MODEL
The IPEF73 model is designed to produce medium to long-term
demographic and employment forecasts for an economic region. A central
feature of the model is the assumption that employment opportunities play a
significant role in determining net migration into or out of the region. As a
result of this assumption, the model is best suited for use in regions where
the number of workers commuting into or out of the region to jobs is not a
significant factor. Such areas would include certain counties, most Standard
Metropolitan Statistical areas and most states. In areas where interregional
commuting is numerically important, it must be accounted for outside the
IPEF73 model structure.
The model is a synthesis of two widely used techniques: the cohort-
survival method of population forecasting and econometric approach to
employment forecasting. In most previous applications these techniques
have been used independent of each other, with the cohort-survival method
considering such factors as birth rates, death rates and historical migration
patterns, and the econometric model deriving forecasts from past trends,
national and state growth patterns, and interindustry relationships. Con-
ceptually, employing these two techniques independently suffers the
shortcoming of ignoring the interdependence of demographic and economic
forces. In fact, when these techniques have been used independently, it has
been necessary at times to subject the forecasts to a reconciliation process
to insure compatibility between population and employment. In the IPEF73
model the cohort-survival and economic techniques are combined so that the
linkages between the demographic and economic sectors are explicit.
The economic sector is divided into two components: basic and local-
serving. The "basic" component sells its products outside the local economy
and is assumed to be a function of the region's comparative economic
advantage (as reflected in historical trends) and the growth of external (i.e.
national) markets, and is, therefore, independent of both the local-serving
component of the economic sector and the demographic sector. The local-
Comprehensive Planning Organization, Interactive Population Employ^
ment Forecasting Model, Technical Users' Manual (San Diego, California, 1974)
p. .
162
-------
serving component, which primarily serves the local population, is assumed
to respond to changes in both the basic economic sector (as changes in basic
employment alter the demand for business-serving activities) and the
demographic sector (as changes in population alter the demand for
household-serving activities).
The demographic sector can also be divided into two components: an
"autonomous" component consisting of births, deaths, retirement migration,
and military migration, and a "dependent" component consisting of births,
deaths, retirement migration, and military migration, and a "dependent™
component consisting of employment-related migration. Births and deaths
are calculated by applying age-specific fertility and survival rates to the
base period population. Retirement and military migration are determined
outside the model framework and are supplied as inputs to the model. The
employment-related migration component is a function of changes in total
employment which, in turn, is the sum of changes in basic and local-serving
employment.
The IPEF73 model produces, for alternative assumed conditions and
policies, demographic and economic forecasts at five-year intervals. The
specific outputs of the model include:
1. Total, household and group quarters population by age, race and
sex;
2. Labor force by age, race and sex;
3. School enrollment for five grade levels, by age, race and sex;
4. Households by age, race and sex of head;
5. Employment by industry.
Since the future values of the factors producing population and
employment changes (i.e. the model inputs) can only be guessed at in most
cases, it is often desirable to produce a range of forecasts reflecting the
reasonable range of forecasts reflecting the reasonable range of the inputs.
163
-------
As a result, a primary objective in developing the model was to produce a
technique that would generate alternative forecasts in response to varying
assumptions.
Perhaps more useful, especially to the decision-maker, is using the
model to simulate the impact of alternative policy decisions on population
and employment growth. Some examples of policies that could be studied
are:
1. Increase in Family Planning Facilities - simulated by reducing
birth rates;
2. Change to a Professional Military - simulated by changing the
size and age structure of the military population and the number
and age structure of military dependents;
3. Increase in Work Training Programs - simulated by increasing
labor force participation rates and reducing the unemployment
rate;
4. Restrictions on Industrial Growth - simulated by reducing the
growth curves for basic employment;
5. Promoting Retirement Communities - simulated by increasing
retirement-related migration.
164
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APPENDIX B
Table B-l
EM PDA FILE FORMATS
Field #
DATA
I.D.
Variable
1
2
3
4
5
6
7
8
9
10
1st
1
5
7
9
10
11
14
17
#
19
22
25
33
41
49
57
65
73
81
89
97
Characters
Last
-T
o
4
8
9
10
13
16
18
21
24
32
40
48
56
64
72
80
88
96
104
# of
3
1
->
1
1
3
3
2
3
3
8
8
8
3
8
8
8
8
9
8
Code
PBZA
z
z
z
z
A
z
z
z
z
z
z
z
z
z
z
z
z
z
z
Field Description
Policy Analysis District Number
Forecast Year
Data Set# - To Ident. Spec. Alternatives
Tested
Run #
Step Code - Identifies Data Stage in the
Chained Process
PAD Sequence Number
Superdistrict Number
Area Code:
Col 17=0 - Inside Cordon = 1 Outside
Cordon
Col 18=0 - D.C. 1-Md. 2-Va.
EPA Areas
# Families in Lower Income Quartile
# Families in Low/Middle Quartile
# Families in Upper/Middle Quartile
# Families in Upper Quartile
# URI HH's
# Employees in Manu/T.C.U.
# Employees in Retail/Wh. Trade
# Employees in F. I. R.E ./Services
# Employees in Government
# Employees in Agriculture/Construction
165
-------
APPENDIX B
Table B-l
(Continued)
EMPDA FILE FORMATS
Field #
11
n
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
1st
105
113
121
129
137
145
153
161
169
177
185
193
201
209
217
225
233
241
249
257
265
273
281
289
297
305
313
321
Characters
Last
112
120
128
136
144
152
160
168
176
184
192
200
208
216
224
232
240
248
256
264
272
280
288
296
304
312
320
328
# of
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
Code
PBZA
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
Field Description
Acres of Residential Land
Acres of Industrial Land
Acres of Commercial Land
Acres of Intensive Institutional Land
Acres of Parks/Rec. Land
Acres of Vacant/Ag Land
Acres of Residual Land (R/W-Streets)
Acres of Land Sewered
Acres of Land Watered
* HH of Size 1
# HH of Size 2
# HH of Size 3
# HH of Size 4
# HH of Size 5
#HH of Size 6 and Over
# of White HH
# of Non-White HH
Population 5 years
Population 5-14 years
Population 15-19 years
Population 20 - 29 years
Population 30 - 49 years
Population 50 - 64 years
Population 65 years + over
^Employees on Commercial Land
# Employees on Industrial Land
# Employees on Intensive Inst. Land
# Employees on Other Land
166
-------
APPENDIX B
Table B-l
EMPDA FILE FORMATS
Field #
39
40
41
42
43
44
45
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
1st
329
337
345
353
361
369
377
497
505
513
521
529
537
545
553
561
569
577
585
593
601
609
617
625
633
641
649
657
665
673
Characters
Last
336
344
352
360
368
376
384
504
512
520
528
536
544
552
560
568
576
584
592
600
608
616
624
632
640
648
656
664
672
680
# of
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
Code
PBZA
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
Field Description
# of Single Family HH
# of Multi Family HH
# of HH with 0 workers
# of HH with 1 worker
# of HH with 2+ workers
Acres of Extensive Institutional Land
Group Quarters Population
Metro Av. - V40*100/V69
Metro Av. - V15*100/(V11 V14)
Median Income Code .5 3.5
Gross HH's/Acre-V69/V97
Net HH's/Res Acre-V69/Vll
Net Emp. Den-V92/(V12+V13+V14)
Used Land/ (Used+ Vac) (Vll V14) *100)/
(Vll V14)+V16)
Used Land/Total Land (Vll V14)*100)/V5
Activity Density - ( V69+V92)/V97
Total Number of HH's (VI V5)
Option 1 - Access X XX. XX Implied Deo
Option 2
Option 3
Option 4
Option 5
Option 6
Option 7 Data = % of Regional
Option 8 Variable V Reached Within
Option 9 X Minutes Via Mode Y Where
Option 10 Y = Skim Tree Table
Option 11
Option 12
Option 13
167
-------
APPENDIX B
Table B-l
(Continued)
EMPDA FILE FORMATS
Field #
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
1st
681
689
697
705
713
721
729
737
745
753
761
769
777
785
793
Characters
Last
688
696
704
712
720
728
736
744
752
760
768
776
784
792
800
# of
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
Code
PBZA
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
Field Description
Option 14
Option 15
Total Trips From Home
Total Trips From Non-Home
# HH With 0 Autos
# HH With 1 Auto
# HH With 2 Autos
# HH With More Than 2 Autos
Total Labor Force
Total Employment
Total Population
$ - Low/Low-Mid Boundary
$ - Low-Mid/Upper-Mid Boundary
$ - Upper-Mid/High Boundary
Total Land Area
168
-------
TABLE B-2
EMPIRIC MODEL OUTPUT FILE FORMAT
Field #
DATA
I.D.
1st
1
5
7
Characters
Last # of
3 3
4 1
8 2
Code
PBZA
z
z
z
Field Description
Policy Analysis District Number
Forecast Year
Data Set* - To Ident. Spec. Alternative;
Tested
Area Systems Descriptions
1
2
3
4
5
6
7
8
9
10
25
33
41
49
57
65
73
81
89
97
32.
40
48
56
64
72
80
88
96
104
8
8
8
8
8
8
8
8
9
8
z
z
z
z
z
z
z
z
z
z
# Families in Lower Income Quartile
# Families in Low/Middle Quartile
# Families in Upper/Middle Quartile
# Families in Upper Quartile
# URI HH's
# Employees in Manu/T.C.U.
# Employees in Retail/Wh. Trade
# Employees in F.I.R.E./Services
# Employees in Government
# Employees in Agriculture/Construction
169
-------
TABLE B-Z
EMPIRIC MODEL OUTPUT FILE FORMAT
Field #
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
1st
105
113
121
129
137
145
153
161
169
177
185
193
201
209
217
225
233
241
249
Characters
Last
112
120
128
136
144
152
160
168
176
184
192
200
208
216
224
232
240
248
256
# of
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
Code
PBZA
z
z
z
z
z
z
z
z
z
z
z
z
z
2
z
z
z
z
z
Field Description
Acres of Residential Land
Acres of Industrial Land
Acres of Commercial Land
Acres of Intensive Institutional Land
Acres of Parks/Rec. Land
Acres of Vacant/ Ag Land
Acres of Residual Land (R/Vf -Streets)
Acres of Land Sewered
Acres of Land Watered
# HH of Size 1
# HH of Size 2
# HH of Size 3
# HH of Size 4
# HH of Size 5
# HH of Size 6 and Over
# of White HH
# of Non-White HH
Population 5 years
Population 5-14 years
170
-------
TABLE B - Z
(Continued)
EMPIRIC MODEL OUTPUT FILE FORMAT
Field #
30
31
32
33
34
35
36
37
38
39
40
41
42
43
1st
257
265
273
281
289
297
305
313
321
329
337
345
353
361
Characters
Last
264
272
280
288
296
304
312
320
328
336
344
352
360
368
* of
8
8
8
8
8
8
8
8
8
8
8
8
8
8
Code
PBZA
z
z
z
i.
z
z
z
z
z
z
z
z
z
z
Field Description
Population 15 - 19 Years
Population 20 - 29 Years
Population 30 - 49 Years
Population 50 - 64 Years
Population 65 Years + Over
# Employees on Commercial Land
# Employees on Industrial Land
# Employees on Intensive Inst. Land
# Employees on Other Land
# of Single Family HH
# of Multi Family HH
# of HH With 0 Workers
# of HH With 1 ¥/orker
# of HH With 2 + Workers
97 793 800
171
-------
APPENDIX C
ESTUARY HYDRODYNAMIC MODEL
EQUATIONS AND CONSTANTS
R = hydraulic radius of channel at start of
° time step (ft)
R = hydraulic radius of channel at middle of
time step (ft)
A = average cross section area of channel at
° start of time step (ft2)
A = average cross section area of channel at
middle of time step (ft2)
B = width of channel (ft)
KQ = friction coefficient at start of time step
K. = friction coefficient at middle of time step
2
g = acceleration due to gravity (ft/sec )
n = Manning roughness coefficient
RQ = hydraulic radius at start of time step (ft)
RX = hydraulic radius at middle of time step (ft)
Subscript Notation:
o = beginning of time step
1 = middle of time step
2 = end of time step
o-l = value during first half of time step
1-2 = value during second half of time step
o-2 = value during full time step
172
[la]
2b]
-------
l= - nl [3b]
nn
Y = change in head along channel between adjacent
junctions at start of time step (ft)
Y = change in head along channel between adjacent
adjacent junctions at middle of time step (ft)
(Y ) = head at next higher junction of channel at beginning
nh of time step (ft)
(Y ) = head at next lower junction of channel at beginning
nl of time step (ft)
(Y ) = head at next higher junction of channel at
middle of time step (ft)
(Y ) = head at next lower junction of channel at
nl middle of time step (ft)
AA = b A Y [ 4a]
o o
AA - b A YI [4b]
AA = change in cross section area of channel between
adjacent junctions at start of time step (ft )
A A = change in cross section area of channel between
adjacent junctions at middle of time step (ft )
b = width of channel (ft)
AY = change in head along channel between adjacent
junctions at start of time step (ft)
173
-------
Y = change in head along channel between adjacent
junctions at middle of time step (ft)
q = V A [5a]
^1 oo
q2 = V^ [5b]
q = volumetric flow rate in channel leaving
junction at midpoint of time step (ft3/sec)
q = volumetric flow rate in channel leaving junction
at end of time step (ft^/sec)
V = velocity in channel between adjacent junctions
at beginning of time step (ft/sec)
V = velocity in channel between adjacent junctions
at middle of time step (ft/sec)
A = average cross section area of channel at start of
time step (ft2)
A = average cross section area of channel at middle
of time step (ft2)
Q2 = Zq2 +QR-QA [6b]
Q = net volumetric flow rate from a junction at
midpoint of time step (ft^sec)
Q2 = net volumetric flow rate from a junction at
end of time step (ft^/sec)
£ q = algebraic sum of volumetric flow rates of all
channels leaving a junction at middle of time
step (ft3/sec)
£ q2 = algebraic sum of volumetric flow rates of all
channels leaving a junction at end of time
step (ft^sec)
QR = volumetric rate of removal, at a junction, for
water supply, irrigation, navigation, etc.during
time step (ft sec)
174
-------
Qa = volumetric rate of addition, at a junction of
liquid residuals, of streamflow, stormwater, etc.
during time step (ft^/sec)
Y = Y -
1 o
At
o-2
[7a]
= Y —
At
0-2
Y = head at junction at middle of time step (ft)
Y = head at junction at end of time step (ft)
Y = head at junction at start of time step (ft)
Q = net volumetric flow rate from a junction
at midpoint of time step (ft^/sec)
Q = net volumetric flow rate from a junction at end
of time step (ft3/sec)
A = surface area of junction equal to one-half the surface
area of the preceeding and succeeding channels
At
o-l = duration of first half of time step (sec)
At „ = duration of whole time step (sec)
o-2
AY
o-l
AY
1-2
1/2
1/2
(Y -Y ) + (Y -YJ
nl
(Y2 Yl)nh + (Y -Y
1 nl
AY
o-i
AY
1-2
average change in head along channel between
adjacent junctions during first half of time
step (ft)
average change in head along channel between
adjacent junctions during last half of time
step (ft)
[8a]
[8b]
* except at boundary condition where the head of the most
seaward junction varies with tide as calculated by
Equation 12
175
-------
(Y ) =. head at next higher junction of channel at
nh start of time step (ft)
(Y ) = head at next lower junction of channel at
nl start of time step (ft)
(Y ) = head at next higher junction of channel at
nh middle of time step (ft)
(Y ) = head at lower junction of channel at
nl start of time step (ft)
(Y ) = head at next higher junction of channel at
nh end of time step (ft)
(Y ) = head of next lower junction of channel at end
nl of time step (ft)
A, = A + b. AY [9a]
1 o .,
o-l
[9b]
A = average cross section area of channel at middle
of time step (ft2)
A = average cross section area of channel at end of
time step (ft2)
A = average cross section area of channel at start
of time step (ft2)
b = width of channel (ft)
AY = average change in head along channel between
adjacent junctions during first half of time
step (ft)
,_„ = average change in head along channel between
adjacent junctions during second half of time
step (ft)
Ay = b AY v AA
A" .j. —— ° ° [10a]
A0AVl Ao X
176
-------
A_v "AYi-2__ . viAAi
+ [iobi
Av
= average velocity gradient along channel
o-l between adjacent junctions during first half
of time step (ft/sec/ft)
Av
£— = average velocity gradient along channel between
1-2 adjacent functions during last half of time
step (ft/sec/ft)
b = width of channel (ft)
x = length of channel (ft)
A = average cross section area of channel at start
of time step (ft)
A = average cross section area of channel at middle
of time step (ft^)
V = velocity in channel between adjacent junctions
at start of time step (ft/sec)
V = velocity in channel between adjacent junctions
at middle of time step ft/sec)
AY = average change in head along channel between
°~ adjacent junctions during first half of time step
AY = average change in head along channel between
*~^ adjacent junctions during last half of time
step (ft)
At = duration of first, half of time step (sec)
o-l
At = duration of last half of time step (sec)
1"~ 2
177
-------
Vl=Vo +
V2=V1 +
" -V AV - K
0 ~A O
Axl-2
r-v AV - K
-L A -L
AX!-2
V
0
Vl
- g AY -1
o
X
- g YX"
X
At
o-l
At
0-2
[Ha]
[lib]
V = velocity in channel between adjacent junctions
at middle of time step (ft/sec)
V = velocity in channel between adjacent junctions
at end of time step (ft/sec)
V = velocity in channel between adjacent junctions
at start of time step (ft/sec)
Av
x
AV
x
o-l
average velocity gradient along channel between
adjacent junctions during first half of time
step (ft/sec/ft)
1-2
= average velocity gradient along channel between
adjacent junctions during last half of time
step (ft/sec/ft)
K =friction coefficient at start of time step
o
K =friction coefficient at middle of time step
r-y
g =acceleration due to gravity (ft/secz)
AY =change in head along channel between adjacent
junctions at start of time step (ft)
AY =change in head along channel between adjacent
junctions at middle of time step (ft)
At =duration of first half of time step (sec)
At _0 =duration of whole time step (sec)
x =channel length (ft.)
178
-------
APPENDIX D
Estuary Quality Model Equations
Parameter and Subscript Notation Used:
( ) = beginning of quality time step
( ) = end of quality time step
( ) = mass transfer due to advection
a
( ) = mass transfer due to diffusion
u = upstream junction of channel
d = downstream junction of channel
nh = next higher numbered junction
nl = next lower numbered junction
( ) = ambient water temperature
( ) = temperature at which reaction
constants are evaluated
const = constituent
r = constituent (NH, BOD, DO, ChA, or NO )
A = liquid residuals (effluent flow) or streamflow
additions to a junction
ChA = Chlorophyll A
179
-------
1]
Vl Bl
(C ) = concentration of constituent in
C0nst 1 at end of time steps - (mg/1 for NH3, BOD,
0 , NO ) and (ug/1 for ChA)
(M ) = mass of constituent in junction at end of
const J . ,_ , ni .
]_ time step (Ib)
V = volume of junction at end of time step (ft )
B = conversion factor 1 Ib/ft for NH BOD, 0 NO
1 16017 mg/1
and 1 Ib/ft3
16017000 ug/1
Vl = V0 + As (Y1- V
V = volume of junction at end of time step (ft )
V = volume of junction at start of time step (ft )
A = surface area of junction equal to one-half the
sxirface area of the preceeding and succeeding
channels (ft2)
Y = head at junction at end of time step (ft)
Y = head at junction of start of time step (ft)
(M ) = (M ) + (AM) + ( AM ) + ( AM )
2 , 20 2 a 2 ^ 2
1 d
reaeration
+ ( A M ) + (A M ) -(AM)
respiration
•'' ( A M ) photosynthesis -- (AM ) benthic
[3]
180
-------
02 1 - mass of oxygen as O in junction at end of time
step (Ib)
(MQ ) = mass of oxygen as O in junction at start of time
2 u step (Ib)
^ 0 ^ = mass of oxygen as O added to junction by
2 a advection from adjacent junctions during time
step (Ib)
(A M ) = Mass of oxygen as O added to junction by diffusion
2 d from adjacent junctions during time step (Ib)
(AM) reaeration = mass of oxygen as 0 in junction added by
2 reaeration during time step (Ib)
(AM ) = mass of oxygen as 0 removed from junction by
2 3 reaction with ammonia during time step (Ib)
'O BOD = mass of oxygen removed from junction by reaction
with carbonaceous material during time step (Ib)
( AM ) respiration = mass of oxygen as O removed from junction by
2 respiration throughout the full depth during time
step (Ib)
(AM )photosynthesis = mass of oxygen as O added during photo
2 synthesis by phytoplankton in the euphotic
zone during 12 hour daylight portion of 24
hour light radiation cycle (Ib)
(AM )
2 benthic = mass of oxygen as O removed from junction by
reaction with the benthos of the junction
during time step (Ib)
181
-------
= (Mconst}l + QA °A t B [4]
const = mass of constituent in junction at
start of time step (Ib)
(M ) = mass of constituent in junction at end
of previous time step (Ib)
Q = volumetric rate of addition, at a junction
of liquid residuals, of streamflow, etc.
during time step (ft^/sec)
t = duration of time step (sec)
C = concentration of constituent in liquid
residuals, streamflow, etc. added to junction
during time step (mg/1 for NH , BOD, O , NO )
and (ug/1 for ChA)
B = conversion factor 1 Ib/ft for NH , BOD, O ,NO
16017 mg/1
and 1 Ib/ft3 for ChA
16017000 ug/1
AM = q C* At B [5]
AM = mass advected from upstream junction to
downstream junction during time step (Ib)
C* = constituent concentration of the advected
mass (mg/1 for NH BOD, O , NO ) (ug/1 for
cholorphyl A)
At = duration of time step (sec)
q, = volumetric flowrate in channel leaving
junction at end of time step (ft3/sec)
1 Ib/ft
16017 mg7l f°* ™3 • B0°' °2 ' N°
Bn = conversion factor 1 Ib/ft
1 Ib/ft3
16017000 ug/1 for ChA
182
-------
C* = Cu -0.25 (Cu-Cd) [6]
C* = constituent concentration of the advected
mass (mg/1, ug/1 for ChA)
C = upstream constituent-concentration at adjacent
junction (mg/1, ug/1 for ChA)
downstream constituent-concenl
adjacent junction (mg/1, ug/1 for ChA)
C, = downstream constituent-concentration at
A AC
AM = mass of constituent transferred by diffusion
from the junction of higher concentration
through a channel to the junction of lower
concentration during the time step (Ib)
K = diffusion coefficient in the channel during
the time step (ft?/sec)
Ac
— = concentration gradient of the channel between
adjacent junctions (mg/l/ft, mg/l/ft for ChA)
X = length of channel (ft)
At = duration of time step
A = cross section area of channel (ft^)
B = conversion factor 1 Ib
453. 5mg
Kd = °4 V R0 [8]
v-
d = diffusion coefficient in the channel
during the time step (ft2/sec)
C = constant (equal to O.2)
V = velocity of flow in channel (ft/sec)
R = hydraulic radius of channel (ft)
183
-------
1/2
VNH
- VNL
[9]
R,
R
O
= hydraulic radius of channel between
adjacent junctions at end of time step (ft)
= hydraulic radius of channel between adjacent
junctions at start of time step (ft)
(Yl>nh
= head at next higher junction of channel at
end of time step (ft)
(Vnh
= head at next higher junction of channel at
start of time step (ft)
= head at next lower junction of channel at
end of time step (ft)
O nl
= head at next lower junction of channel at
start of time step (ft)
(AMI
2
reaeration
= K D V B.
r2
[10]
= mass of oxygen in junction added by
2 reaeration reaeration during time step (Ib)
K
K
V
ratio of mass of oxygen in junction added by
reaeration to the mass of oxygen deficit at
start of time step
dissolved oxygen saturation deficit
occurring during time step (mg/1)
volume of junction at start of time step
conversion factor 1 lb/ft' _____
16017 mg/1
l-(e) -(K2) At
t
[ 11 )
184
-------
Kr ~ ra,tio of mass of oxygen added by reaeration
2 during time step to the mass of oxygen deficit
at start of time step.
2^ = reaeration coefficient (day , )
e = 2.718, base of Naperian log system
At = duration of time step (sec)
= °
YQ [12]
b
(K ) = reaeration coefficient (day )
V = velocity in channel (ft/sec)
YQ = depth (ft)
a = proportionality constant between log
n
K0 and log V
^ n
b = proportionality constant between log K and log
Yo
(C) = constant in reoxygenation equation which
varies with temperature
(Ot = (020
(c)
t = constant in reoxygenation equation at
water temperature simulated
o
(C) = constant in reoxygenation equation at 20
centigrade
t = water temperature simulated ( C)
6 = constant reflecting the effect of temper-
ature on the reoxygenation equation
185
-------
2NH3
( AM )
2 NH = mass of oxygen as O removed from
junction by reaction with ammonia
as N during time step (Ib)
4_57 = ratio of ultimate nitrogenous oxygen
demand as 0 to ammonia as N *
( AM ) = mass of ammonia as N removed from
3 junction by reaction with dissolved
oxygen as 0 during time step (Ib)
respiration^ VQ K B (C At [15]
M = mass of oxygen as O removed from
2) . . junction by respiration throughout
respiration ^& fu;Q depth Qf thQ junction during
time step (Ib)
V = volume of junction at start of time
° step (ft3)
K = rate of oxygen consumption during
res^ respiration of phytoplankton capable
of photosynthesis (mg O /hr/ug ChA)
(C ) = concentration of chlorophyll A in
junction at start of time step (ug/1)
At = duration of time step (hr)
B = conversion factor 1 Ib
453.6 mg
* NH,
N°2
(3/2
(
+ 3/2 0? C~~^ HN02 + H20
+ 1/2 0 ^=^- NO
+ 1/2) (Mol.wt.O as O )
1 ) (Mol.wt.NH.as N)
64 = 4 57
14
186
-------
photosynthesis = Vp KphotQ B]_ (CchA} At [ 16 ]
(AM ) photosynthesis = mass of oxygen as O added to
2 junction by photosynthesis in
the euphotic zone during 12 hour
daylight portion of 24 hour light
radiation cycle (Ib)
V = volume of euphotic zone at start of time step
P (ft3)
photo = rate of oxygen production during photosynthesis
by phytoplankton in the euphotic zone during
time step (mg O /hr/ug ChA)
(C ) = concentration of chlorophyll A in junction
at start of time step (ug/1)
B = conversion factor 1 Ib
453.6mg
At = duration of time step (hr)
v = A E if V^-V
p s p Op
V = V if V< V
p o o p
V = volume of euphotic
p time step (ft3)
7 = volume of junction
O
[ 17a]
[ 17b ]
zone of junction at start of
at start of time step (ft3)
2
A = surface area of junction (ft )
E = depth of euphotic
P
zone (ft)
. = As \enth At B2
2 benthic
(AM ) benthic = mass of oxygen as O removed from
2 junction by reaction with the benthos
of the junction during time step (Ib)
2
A = surface are of the junction (ft )
S
187
-------
benth = rate of oxygen consumption by benthos
(g/m2 day)
At = duration of time step (day)
B = conversion factor
K
3 a 3 3 b
= mass of ammonia as N in junction at end of
i time step (Ib)
(M ) = mass of ammonia as N in junction at start
3 o of time step (Ib)
( AM ) = mass of ammonia as N added to junction by
a diffusion from adjacent junctions during
time step (Ib)
(AM ) = mass of ammonia as N removed from junction by
3 b reaction with oxygen during time step (Ib)
V = (1-Kr> Co vo Bi [20]
3 b 1
(AM, )
NH b = mass of ammonia as N removed from junction
by reaction with oxygen to form nitrate
during time step (Ib)
K = ratio of mass of ammonia in junction at
1 end of time step to mass of ammonia in
junction at start of time step due only
to decay
C = concentration of ammonia as N ir junction
at start of time step (mg/1)
V = volume of junction at start of time step (ft)
B = conversion factor 1 Ib/ft
16017 mg/l
= NH
188
-------
-(K ) At [21]
K = ratio of mass of constituent in junction at
1 end of time step to mass constituent at start
of time step at water temperature t
reaction rate of constituent to form
constituent at water temperature t (day
K = reaction rate of constituent to form a different
base e) '
v
e = 2.718, base of Naperian log system
At = duration of time step
r = NH , BOD, ChA, or NO
= (V2Q e (t-20) [22]
(K ) = reaction rate of a constituent to form a different
t constituent at water temperature t; also called
the decay rate (day , base e)
(K ) = decay rate of a constituent at 20° centigrade
20 (day-1, base e)
6 = constant reflecting the effect of temperature
on the reaction rate of a constitutent
t = water temperature simulated (°C)
(MBOD°1= BQDa BOD -BODb
u
) , = mass of BOD as 0 in junction at end of
1 . , , b . 2
time step (Ib)
(M ) = mass of BOD as O in junction at start of
(Ib)
time step
( A M ) mass of BOD as O added to junction by advection from
a adjacent junctions during time step (Ib)
( AM) = mass of BOD as O added to junction by diffusion
d from adjacent junctions during time step (Ib)
( A M ) = mass of BOD,, as O removed from junction by reaction
b with dissolved oxygen during time step (Ib)
189
-------
( AM )
2 BOD
= BOFD
[24]
BOPD
AMBOD)]
mass of oxygen as O removed from junction
by reaction of dissolved oxygen with bio-
chemical oxygen demanding substances during
time step (Ib)
ratio of ultimate oxvgen demand to.five day
biochemical oxygen demand
mass of BOD as O removed from junction by
reaction with dissolved oxygen as O during
time step (Ib)
ratio of oxygen as 0 to ultimate BOD
1 mg O
1 mg BOD
AMBOD)]
COVOBI
AM_, __),
BOD
1 - K
vo
i
BODP
BODF
= mass of five day BOD as O [25]'
removed from junction by reaction
with oxygen during time step (Ib)
= ratio of biochemcial oxygen demand exerted
during time step to ultimate oxygen demand at
start of time step
concentration of BOD as O in junction
at start of time step (mg/1)
volume of junction at start of time step (ft )
conversion factor 1 Ib/ft
16017mg/l
e (K^) t(5 days) [26]
ratio of ultimate oxygen demand to
five day biochemical oxygen demand
= reaction rate of oxygen demanding substances
with dissolved oxygen, at water temperature t;
also called the decay rate (day , base e)
190
-------
(MChA) = (MChA) + (A MChA) + ( A MChA)
-L O 3. 2
)b
B,
[27;
(MChA)
(MChA)
(AMChA).
(AMChA)
(AMChA),
i =
o
mass of chlorophyll A in junction at end
of time step (Ib)
mass of chlorophyll A in junction at
start of time step (Ib)
mass of chlorophyll A added to junction by
advection from adjacent junctions during time
step (Ib)
mass of chlorophyll A added to junction by
diffusion from adjacent junctions during time
step (Ib)
mass of chlorophyll A removed from junction by
predators, etc. during time step (Ib)
mass of nitrate as N removed from junction by
incorporation into photosynthetic phytoplankton
during time step (Ib)
B,
ratio of chlorophyll A to nitrate as N in phto-
synthetic phytoplankton 93mgChA
Img atom N0_
= conversion factor 1 Ib
453.6 mg
( AMChA),
[28]
( AMChA).
mass of chlorophyll A removed from
junction by predators, etc. during time
step (Ib)
K
V
ratio of mass of chlorophyll A in junction
at end of time step to mass of chlorophyll
A in junction at start of time step due only
to decay (Ib)
concentration of chlorophyll A in junction
start of time step (mg/1)
volume of junction at start of time step (ft )
conversion factor 1 Ib/ft
16017000ug/l
191
-------
(A)d [293
.3 J_
>b
(M ) = mass of nitrate as N in junction at end
3 of time step (Ib)
.,) = mass of nitrate as N in junction at
start of time step (Ib)
( AM ) = mass of nitrate as N added to junction by advection
3 from adjacent junction during time step (Ib)
) , = mass of nitrate as N added to junction by
3 diffusion from adjacent junctions during
time step (Ib)
_ ,, = mass of nitrate as N removed from junction by
3 incorporation into phtosynthetic phytoplankton
during time step (Ib)
AM . = mass of ammonia as N removed from junction by
3 reaction with oxygen to form -'nitrate during time
step (Ib)
R = ratio of ammonia as N to nitrate as N 1 mgNO_ as N
1 .mgNH as N
NO ) = mass of nitrate as N removed from junction
by incorporation into photosynthetic phytoplankton
during time step (Ib)
K = ratio of mass of nitrate as N in junction at end
1 of time step to mass of nitrate in junction at start
of time step due only to decay
C = concentration of nitrate in junction at start of
time step (mg/1)
V = volume of junction at start of time step (ft )
B^ = conversion factor 1 Ib/ft
16017 mg/1
192
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CONSTANTS
TIME STEP
At = 30 min
DIFFUSION
C = 1.0
Y
REAERATION (using O'Connor Dobbins Equation)
(02Q = 12.9
a = 1/2
b = -3/2
6 = 1.021
RESPIRATION
O.0006 < K < 0.0008 mg 0,,/hr/ug ChA
resp — a 2 y
PHOTOSYNTHESIS
K = O.012 mg 0 /hr/ug ChA by day
K photo = O by night
BENTHIC DEMAND
K benth = lm° gram f)2/m /day
REACTION RATES (first order)
CONSTITUENT DECAY ^ ^^
PROCESS t=20^ 1 t t=27°C
NH3
BOD
ChA
NO,
oxidation
oxidation
predation
uptake
0.23
0.17
0.04
0.09
O.23
0.23
0.04
0.09
193
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CONVERSION CONSTANTS
R = 93 ug ChA.
1 mg.NO_ as N
R = 1 mg N0_ as N
1 mg NH as N
•J
1 mg 0_
1 mg BOD ult as
O SATURATION VS. TEMPERATURE
C = 14.652 - 0.41022T + O.0079910T2 - O.00077779T3
LIQUID RESIDUAL CONCENTRATIONS
CQ = 2.0 mg/1
STORMWATER RUNOFF CONCENTRATIONS
CQ = SATURATION
C =°
WATER TEMPERATURE
t = 27C
194
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TECHNICAL REPORT DATA
(Please read Irmtfuftions on the reverse before completing)
1. REPORT NO.
EPA-600/5-78-006b
2.
4. TITLE AND SUBTITLE
A Demonstration of Areawide Water Resources Planning -
Users Manual
7. AUTHOR(S)
C.S. Spooner, J. Promise, P.H. Graham
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Metropolitan Washington Council of Governments
1225 Connecticut Avenue, N.W.
Washington, B.C. 20036
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Research & Development
Washington, B.C. 20460
•»5. SUPPLEMENTARY NOTES
3. RECIPIENT'S ACCESSION!*®.
5. REPORT DATE
June 1975
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATJOM REPORT NO.
1O. PROGRAM ELEMENT NO.
1BA030
11. CONTRACT/GRANT NO.
68-01-3704
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/16
16. ABSTRACT " '
The MWCOG Framework Water Resources Planning Model is a comprehensive analytical
tool for use in areawide water resources management planning. The physical simula-
tion portion was formed by linking component computer models which test alternative
future community development patterns by small area, estimate water demands by usage
categories, calculate sewage flows based on water demands and add infiltration/inflow
simulate stormwater runoff, test application of alternative waste treatment manage-
ment systems, and simulate the quality response of the region's major water body.
The Users Manual describes the function and operation of each component model,
alternative models that could have been used, and elements of post computational
analyses described. The Users Manual is intended to be used in conjunction with
other references which are cited.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Water resources planning, Land use
planning, Storm runoff, Water supply,
Water quality, Systems analysis, Decision
making, Computer simulation, Water
pollution sources, Regional analysis,
Data collection, Estuary, Social aspects,
Environmental effects, Economic impacts
Resource allocation
18. DISTRIBUTION STATEMENT
Unlimited release
b.lDENTIFIERS/OPEN ENDED TERMS C. COS ATI Field/Group
Metropolitan Washington, Qg^ Qgg Q^Q
Areawide waste treatment 05C* 056* 05D?
management planning, ncr' j^/ A7A'
•^ -r-i j i -n ' W^A-I , WV-L*' , \J 8 M.
Potomac Estuary model,
Stormwater runoff model,
Framework for assessing
fiscal, social and
environmental effects '.
19. SECURITY CLASS (This Report) 21. NO. Of PAGES
UNCLASSIFIED 195
20. SECURITY CLASS (This page) 22. PRICE
UNCLASSIFIED
EPA Form 2220-1 (9-73>
195
MJ.S. GOVERNMENT PRINTING OFFICE: 1978 2MJ-880/TI
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