United States
Environmental Protection
Agency
EPA 600/R-13/174 | August 2013
www.epa.gov/ord
Watershed Management
Optimization Support Tool
(WMOST) v1
USER MANUAL
AND CASE STUDY EXAMPLES
Source Water
Treated Water
Areas, Runoff&
Recharge Rates
to External SW
to External GW
O
GW Infiltration
Non-Potable
Use
I Interbasin |
Transfer:
"|
\wastewateix
toSW
Water Reuse
Fac
ity
Office of Research and Development
National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division
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EPA 600/R-13/174 | August 2013
Watershed Management Optimization
Support Tool (WMOST) vl
User Manual and
Case Study Examples
EPA Project Team
Naomi Detenbeck and Marilyn ten Brink,
NHEERL, Atlantic Ecology Division
Narragansett, RI 02882
Alisa Morrison
Student Services Contractor at ORD, NHEERL, Atlantic Ecology Division
Narragansett, RI 02882
Yusuf Mohamoud
ORD, NERL, Ecosystems Research Division
Athens, GA 30605
Ralph Abele and Jackie LeClair
Region 1
Boston, MA 02109
Abt Associates Project Team
Viktoria Zoltay, Becky Wildner, Lauren Parker and Isabelle Morin, Abt Associates, Inc.
Nigel Pickering, Horsley Witten Group under subcontract to Abt Associates Inc.
Richard M. Vogel, Tufts University under subcontract to Abt Associates Inc
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WMOST v1 User Manual and Case Study Examples
The information in this document has been funded by the U.S. Environmental Protection Agency
(EPA), in part by EPA's Green Infrastructure Initiative, under EPA Contract No. EP-C-07-023/ Work
Assignment 32 to Abt Associates, Inc. It has been subjected to the Agency's peer and administrative review,
and it has been approved for publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
Although a reasonable effort has been made to assure that the results obtained are correct, the
computer programs described in this manual are experimental. Therefore, the author and the U.S.
Environmental Protection Agency are not responsible and assume no liability whatsoever for any
results or any use made of the results obtained from these programs, nor for any damages or litigation
that result from the use of these programs for any purpose.
Abstract
The Watershed Management Optimization Support Tool (WMOST) is intended to be used as a
screening tool as part of an integrated watershed management process such as that described in EPA's
watershed planning handbook (EPA 2008).: The objective of WMOST is to serve as a public-domain,
efficient, and user-friendly tool for local water resources managers and planners to screen a wide-
range of potential water resources management options across their watershed or jurisdiction for cost-
effectiveness as well as environmental and economic sustainability (Zoltay et al 2010). Examples of
options that could be evaluated with the tool include projects related to stormwater, water supply,
wastewater and water-related resources such as Low-Impact Development (LID) and land
conservation. The tool is intended to aid in evaluating the environmental and economic costs,
benefits, trade-offs and co-benefits of various management options. In addition, the tool is intended
to facilitate the evaluation of low impact development (LID) and green infrastructure as alternative or
complementary management options in projects proposed for State Revolving Funds (SRF).
WMOST is a screening model that is spatially lumped with a daily or monthly time step. The model
considers water flows but does not yet consider water quality. The optimization of management
options is solved using linear programming. The target user group for WMOST consists of local
water resources managers, including municipal water works superintendents and their consultants.
This document includes a user guide and presentation of two case studies as examples of how to
apply WMOST. Theoretical documentation is provided in a separate report (EPA/600/R-13/151).
Keywords: Integrated watershed management, water resources, decision support, optimization, green
infrastructure
1 EPA. 2008. Handbook for Developing Watershed Plans to Restore and Protect Our Waters. March 2008. US
Environmental Protection Agency. Office of Water. Nonpoint Source Control Branch, Washington, D.C. EPA 841-B-
08-002
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Preface
Integrated Water Resources Management (IWRM) has been endorsed for use at multiple scales. The
Global Water Partnership defines IWRM as "a process which promotes the coordinated development
and management of water, land and related resources, in order to maximize the resultant economic
and social welfare in an equitable manner without compromising the sustainability of vital
ecosystems".2 IWRM has been promoted as an integral part of the "Water Utility of the Future"3 in
the United States. The American Water Resources Association (AWRA) has issued a position
statement calling for implementation of IWRM across the United States and committed the AWRA to
help strengthen and refine IWRM concepts.4 The U.S. Environmental Protection Agency (EPA) has
also endorsed the concept of IWRM, focusing on coordinated implementation of stormwater and
wastewater management.5
Several states and river basin commissions have started to implement IWRM.6 Even in EPA's Region
1 where water is relatively plentiful, states face the challenge of developing balanced approaches for
equitable and predictable distribution of water resources to meet both human and aquatic life needs
during seasonal low flow periods and droughts. The state of Massachusetts recently spearheaded the
Sustainable Water Management Initiative (SWMI) process to allocate water among competing human
and aquatic life uses in a consistent and sustainable fashion.7
Stormwater and land use management are two aspects of IWRM which include practices such as
green infrastructure (GI, both natural GI and constructed stormwater BMPs), low-impact
development (LID) and land conservation. In recent years, the EPA's SRF funding guidelines have
been broadened to include support for green infrastructure at local scales-e.g., stormwater best
management practices (BMPs) to reduce runoff and increase infiltration-and watershed scales-e.g.,
conservation planning for source water protection. Despite this development, few applicants have
2 UNEP-DHI Centre for Water and Environment. 2009. Integrated Water Resources Management in Action. WWAP, DFfl
Water Policy, UNEP-DHI Centre for Water and Environment.
3 NACWA, WERF, and WEF. 2013. The Water Resources Utility of the Future: A Blueprint for Action. National
Association of Clean Water Agencies (NACWA), Water Environment Research Foundation (WERF) and Water
Environment Federation (WEF), Washington, D.C.
4 http://www.awra.org/policy/policy-statements-water-vision.html
5Nancy Stonermemo: http://water.epa.gov/infrastructure/greeninfrastructure/upload/memointegratedmunicipalplans.pdf
AWRA. 2012. Case Studies in Integrated Water Resources Management: From Local Stewardship to National Vision.
American Water Resources Association Policy Committee, Middleburg, VA.
7 MA EAA. 2012. Massachusetts Sustainable Water Management Initiative Framework Summary (November 28, 2012);
http://www.mass.gov/eea/agencies/massdep/water/watersheds/sustainable-water-management-
initiative-swmi.html
III
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WMOST v1 and
taken advantage of these opportunities to try nontraditional approaches to water quality
improvement.8 In a few notable cases, local managers have evaluated the relative cost and benefit of
preserving green infrastructure compared to traditional approaches. In those cases, the managers have
championed the use of green infrastructure as part of a sustainable solution for IWRM but these
examples are rare.9
Beginning with the American Recovery and Reinvestment Act (ARRA), and continued with 2010
Appropriations language, Congress mandated a 20% set-aside of SRF funding for a "Green Project
Reserve (GPR)", which includes green infrastructure and land conservation measures as eligible
projects in meeting water quality goals. The utilization of the GPR for green infrastructure projects
has been relatively limited and responses have varied widely across states. According to a survey of
19 state allocations of Green Project Reserve funds, only 18% of funds were dedicated to green
infrastructure projects and none of these projects were categorized as conservation planning to
promote source water protection.7 The state of Virginia passed regulations banning the use of ARRA
funds for green infrastructure projects until after wastewater treatment projects had been funded.7 In
New England, states exceeded the 20% GPR mandate and used 30% of their ARRA funds for the
GPR, but directed most of the funds (76%) to energy efficiency and renewables; other uses of ARRA
funds included 12% for water efficiency, 9% for green infrastructure, and 3% for environmentally
innovative projects.
In order to assist communities in the evaluation of GI, LID, and land conservation practices as part of
an IWRM approach, EPA Office of Research and Development, in partnership with EPA Region 1,
supported the development of the Watershed Management Optimization Support Tool (WMOST).
WMOST is based on a recent integrated watershed management optimization model that was created
to allow water resources managers to evaluate a broad range of technical, economic, and policy
management options within a watershed.10 This model includes evaluation of conservation options for
source water protection and infiltration of stormwater on forest lands, green infrastructure stormwater
BMPs to increase infiltration, and other water-related management options. The current version of
8 American Rivers. 2010. Putting Green to Work: Economic Recovery Investments for Clean and Reliable Water. American
Rivers, Washington, D.C
9 http://www.crwa.org/blue.html, http://v3.mmsd.com/greenseamsvideol.aspx
10 Zoltay, V.I. 2007. Integrated watershed management modeling: Optimal decision making for natural and human
components. M.S. Thesis, Tufts Univ., Medford, MA.; Zoltay, V.I., R.M. Vogel, P.H. Kirshen, and K.S. Westphal. 2010.
Integrated watershed management modeling: Generic optimization model applied to the Ipswich River Basin. Journal of
Water Resources Planning and Management.
IV
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WMOST focuses on management options for water quantity endpoints. Additional functionality to
address water quality issues is one of the high priority enhancements identified for future versions.
Development of the WMOST tool was overseen by an EPA Planning Team. Priorities for update and
refinement of the original model9 were established following review by a Technical Advisory Group
comprised of water resource managers and modelers. Case studies for each of three communities
were developed to illustrate the application of IWRM using WMOST; two of these case studies
(Upper Ipswich River, and Danvers/Middleton, MA) are presented here. WMOST was presented to
stakeholders in a workshop held at the EPA Region 1 Laboratory in Chelmsford, MA in April 2013,
with a follow-up webinar on the Danvers/Middleton case study in May 2013. Feedback from the
Technical Advisory Group and workshop participants has been incorporated into the user guide and
theoretical documentation for WMOST.
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WMOST v1 User Manual and Case Study Examples
Acknowledgements
WMOST builds on research funded by the National Science Foundation Graduate Research
Fellowship Program and published in Zoltay, V. Kirshen, P.H. Vogel, R.M. and Westphal, K.S. 2010.
"Integrated Watershed Management Modeling: Optimal Decision Making for Natural and Human
Components." Journal of Water Resources Planning and Management, 136:5, 566-575.
EPA Project Team
Naomi Detenbeck and Marilyn ten Brink, U.S. EPA ORD, NHEERL, Atlantic Ecology Division
Alisa Morrison, Student Services Contractor at U.S. EPA ORD, NHEERL, Atlantic Ecology Division
Ralph Abele and Jackie LeClair, U.S. EPA Region 1
Yusuf Mohamoud, U.S. EPA ORD, NERL, Ecosystems Research Division
Technical Advisory Group
Alan Cathcart, Concord, MA Water/Sewer Division
Greg Krom, Topsfield, MA Water Department
Dave Sharpies, Somersworth, NH Planning and Community Development
Mark Clark, North Reading, MA Water Department
Peter Weiskel, U.S. Geological Survey, MA-RI Water Science Center
Kathy Baskin, Massachusetts Executive Office of Energy and Environmental Affairs
Steven Estes-Smargiassi, Massachusetts Water Resources Authority
Hale Thurston, U.S. EPA ORD, NRMRL, Sustainable Technology Division
Rosemary Monahan, U.S. EPA Region 1
Scott Horsley, Horsley Witten Group
Kirk Westphal, COM Smith
James Limbrunner, Hydrologies, Inc.
Jay Lund, University of California, Davis
Reviewers
Theoretical Documentation
Marisa Mazzotta, U.S. EPA ORD, NHEERL, Atlantic Ecology Division
Mark Voorhees, U.S. EPA Region 1
Michael Tryby, U.S. EPA ORD, NERL, Ecosystems Research Division
WMOST Tool. User Guide and Case Studies
Daniel Campbell, U.S. EPA ORD, NHEERL, Atlantic Ecology Division
Alisa Richardson, Rhode Island Department of Environmental Management (partial review)
Alisa Morrison, Student Services Contractor at U.S. EPA ORD, NHEERL, Atlantic Ecology Division
Jason Berner, U.S. EPA OW, OST, Engineering Analysis Division
VI
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Table of Contents
Table of Contents
Notice ii
Abstract ii
Preface iii
Acknowledgements vi
Exhibits viii
1. Background 1
1.1 Objective of the Tool 1
1.2 Overview 1
2. Getting Started 6
2.1 Preparing for a Model Run 6
Defining Hydrologic Response Units 6
Defining the Study Area 7
Defining the Modeling Time Period 7
2.2 Setting Up and Running the Model 8
System Requirements 8
The User Interface-Step by Step 8
2.3 Evaluating Results 27
2.4 User Tips 29
3. Case Study Examples 31
3.1 Upper Ipswich River Basin 31
Optimization Scenario 33
Results 33
3.2 Danvers and Middleton, Massachusetts 37
3.2.1 Model Setup 38
3.2.2 Simulation 39
3.2.3 Optimization 41
Scenario 1: Base 43
Scenario 2: Drought Resistant Landscaping and Reduced Summer Water Use 45
Scenario 3: Trade-off Curve-In-Stream Flow and Costs 46
Scenario 4: Exclusion of Interbasin Transfer of Wastewater and Double In-Stream Flow
Criteria 49
Scenario 5: Sensitivity of Solutions to the Capital Cost of Interbasin Transfer of Water.. 50
Conclusions 51
3.2.4 Refinements for Input Data and WMOST Capabilities 52
4. Appendix A. Danvers Middleton Case Study Input Data 53
VII
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WMOST v1 User Manual and Case Study Examples
Exhibits
1. Schematic of Potential Water Flows in the WMOST 2
2. Summary of Management Goals and Management Practices 4
3. Map of the Upper Ipswich River Basin 31
4. Upper 1KB Water Supply and Wastewater Services 32
5. Hydrologic Conditions in 1999 33
6. Results for Meeting Minimum In-Stream Flow and Human Demand 34
7. Danvers and Middleton, MA in the IRB 37
8. Subbasins and Reaches of the IRB and Danvers and Middleton Town Boundaries 39
9. Comparison of In-Stream Flows 41
10. Base Scenario Results 43
11. Base Scenario-Modeled and Measured In-Stream Flows 44
12. Base Scenario-Modeled and Target In-Stream Flows 44
13. Reduced Summer Water use Scenario Results 45
14. In-Stream Flow Criteria 46
15. Results for Increasing In-Stream Flow Criteria 47
16. Trade-Off Curve Between Increasing In-Stream Flow and Total Cost 48
17. Results for Scenario with Exclusion of Interbasin Transfer of Wastewater
with Double In-Stream Flow Criteria 50
18. Results for Reducing the Capital Cost of Interbasin Transfer of Water 51
VIM
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Background
1. Background
l.l
Objective of the Tool
The Watershed Management Optimization Support Tool (WMOST) is a public-domain software
application designed to aid decision making in integrated water resources management. WMOST is
intended to serve as an efficient and user-friendly tool for water resources managers and planners to
screen a wide-range of strategies and management practices for cost-effectiveness and environmental
sustainability in meeting watershed or jurisdiction management goals (Zoltay et al 2010).10
WMOST identifies the least-cost combination of management practices to meet the user specified
management goals. Management goals may include meeting projected water supply demand and
minimum and maximum in-stream flow targets. The tool considers a range of management practices
related to water supply, wastewater, nonpotable water reuse, aquifer storage and recharge,
stormwater, low-impact development (LID) and land conservation, accounting for the both the cost
and performance of each practice. In addition, WMOST may be run for a range of values for
management goals to perform a cost-benefit analysis and obtain a Pareto frontier or trade-off curve.
For example, running the model for a range of minimum in-stream flow standards provides data to
create a trade-off curve between increasing in-stream flow and total annual management cost.
WMOST is intended to be used as a screening tool as, part of an integrated watershed management
process such as that described in EPA's watershed planning handbook (EPA 2008),1 to identify the
strategies and practices that seem most promising for more detailed evaluation. For example, results
may demonstrate the potential cost-savings of coordinating or integrating the management of water
supply, wastewater and stormwater. In addition, the tool may facilitate the evaluation of LID and
green infrastructure as alternative or complementary management options in projects proposed for
State Revolving Funds (SRF). As of October 2010, SRF Sustainability Policy calls for integrated
planning in the use of SRF resources as a means of improving the sustainability of infrastructure
projects and the communities they serve. In addition, Congress mandated a 20% set-aside of SRF
funding for a "Green Project Reserve" which includes green infrastructure and land conservation
measures as eligible projects in meeting water quality goals.
1.2
Overview
WMOST combines an optimization framework with water resources modeling to evaluate the effects
of management decisions within a watershed context. The watershed system modeled in WMOST
version 1 is shown in Exhibit 1. The exhibit shows the possible watershed system components and
potential water flows among them.
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WMOST v1 User Manual and Case Study Examples
Exhibit 1. Schematic of Potential Water Flows in the WMOST
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Background
The principal characteristics of WMOST include:
• Implementation in Microsoft Excel 2010© which is linked seamlessly with Visual Basic for
Applications (VBA) and a free, linear programming (LP) optimization solver, eliminating the
need for specialized software and using the familiar Excel platform for the user interface;
• User-specified inputs for characterizing the watershed, management practices, and management
goals and generating a customized optimization model (see Exhibit 2 for a list of available
management practices and goals);
• Use of Lp_solve 5.5, a LP optimization solver, to determine the least-cost combination of
practices that achieves the user-specified management goals (See Section 3 in the separate
Theoretical Documentation for details on Lp_solve 5.5, LP optimization, and the software
configuration);
• Spatially lumped calculations modeling one basin and one reach but with flexibility in the number
of hydrologic response units (HRUs),11 each with an individual runoff and recharge rate;
• Modeling time step of a day or month without a limit on the length of the modeling period;12
• Solutions that account for both the direct and indirect effects of management practices (e.g., since
optimization is performed within the watershed system context, the model will account for the
fact 1) that implementing water conservation will reduce water revenue, wastewater flow and
wastewater revenue if wastewater revenue is calculated based on water flow or 2) that
implementing infiltration-based stormwater management practices will increase aquifer recharge
and baseflow for the stream reach which can help meet minimum in-stream flow requirements
during low precipitation periods, maximum in-stream flow requirements during intense
precipitation seasons, and water supply demand from increased groundwater supply);
• Ability to specify up to fifteen stormwater management options, including traditional, green
infrastructure or LID practices;
• A sustainability constraint that forces the groundwater and reservoir volumes at the start and end
of the modeling period to be equal;
• Enforcement of physical constraints, such as the conservation of mass (i.e., water), within the
watershed; and
• Consideration of water flows only (i.e., no water quality modeling yet).
The rest of this document is organized as follows. Section 2 provides directions for basic model setup
and application with screenshots as well as the steps for performing sensitivity and trade-off analyses.
A case study example for a watershed is presented in Section 3.1 for the Upper Ipswich River
Watershed. Another case study for two towns sharing one water utility is presented in Section 3.2 for
Danvers and Middleton, Massachusetts. The WMOST files for these case studies for all scenarios are
available and may be used as a source of default data, especially for similar watersheds and similar
sized water and wastewater systems.
11 Land cover, land use, soil, slope and other land characteristics affect the fraction of precipitation that will runoff, recharge
and evapotranspire. Areas with similar land characteristics that respond similarly to precipitation are termed hydrologic
response units.
12 While the number of HRUs and modeling period are not limited, solution times are significantly affected by these model
specifications.
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WMOST v1 and
A separate Theoretical Documentation report provides a detailed description of WMOST including a
mathematical description and the internal configuration of the software applications that constitute the
model.
Exhibit 2. Summary of Management Goals and Management Practices13
Management Practice
Land conservation
Stormwater management via
traditional, green
infrastructure or low impact
development practices
Surface water storage
capacity
Surface water pumping
capacity
Groundwater pumping
capacity
Change in quantity of
surface versus groundwater
pumping
Potable water treatment
capacity
Leak repair in potable
distribution system
Wastewater treatment
capacity
Infiltration repair in
wastewater collection
system
Action14
Increase area of
land use type
specified as
'conservable'
Increase area of
land use type
treated by specified
management
practice
Increase maximum
storage volume
Increase maximum
pumping capacity
Increase maximum
pumping capacity
Change in pumping
time series for
surface and
groundwater
sources
Increase maximum
treatment capacity
Decrease
% of leaks
Increase million
gallons per day
(MGD) treated
Decrease
% of leaks
Model Component
Affected
Land area allocation
Land area allocation
Reservoir/Surface
Storage
Potable water
treatment plant
Potable water
treatment plant
Potable water
treatment plant
Potable water
treatment plant
Potable water
treatment plant
Wastewater
treatment plant
Wastewater
treatment plant
Impact
Preserve runoff & recharge
quantity & quality
Reduce runoff, increase
recharge, treatment
Increase storage, reduce
demand from other sources
Reduce quantity and/or timing
of demand from other sources
Reduce quantity and/or timing
of demand from other sources
Change the timing of
withdrawal impact on water
source(s)
Treatment to standards, meet
potable human demand
Reduce demand for water
quantity
Maintain water quality of
receiving water (or improve if
sewer overflow events)
Reduce demand for
wastewater treatment capacity
' The user may specify which practices are available for their study area and are to be included in the optimization.
Directions for this are provided with each practice in the User Manual and WMOST interface.
' Please refer to the separate Theoretical Documentation for the specific effect of each management practice.
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Management Practice
Water reuse facility
(advanced treatment)
capacity
Nonpotable distribution
system
Aquifer storage & recharge
(ASR) facility capacity
Demand management by
price increase
Direct demand management
Interbasin transfer - potable
water import capacity
Interbasin transfer -
wastewater export capacity
Minimum human water
demand
Minimum in-stream flow
Maximum in-stream flow
Action14
Increase MGD
treated
Increase MGD
delivered
Increase MGD
treated & injected
Increase % of price
Percent decrease in
MGD
Increase or
decrease MGD
delivered
Increase or
decrease MGD
delivered
Minimum MGD
Minimum ft3/sec
Maximum ftVsec
Model Component
Affected
Water reuse facility
Nonpotable water
use
ASR facility
Potable and
nonpotable water
and wastewater
Potable and
nonpotable water
and wastewater
Interbasin transfer -
potable water import
Interbasin transfer -
wastewater export
Groundwater and
surface water
pumping and/or
interbasin transfer
Surface water
Surface water
Impact
Produce water for nonpotable
demand, Aquifer storage &
recharge (ASR), and/or
improve water quality of
receiving water
Reduce demand for potable
water
Increase recharge, treatment,
and/or supply
Reduce demand
Reduce demand
Increase potable water supply
or reduce reliance on out of
basin sources
Reduce need for wastewater
treatment plant capacity or
reduce reliance on out of basin
services
Meet human water needs
Meet in-stream flow
standards, improve ecosystem
health and services, improve
recreational opportunities
Meet in-stream flow
standards, improve ecosystem
health and services by
reducing scouring, channel
and habitat degradation, and
decrease loss of public and
private assets due to flooding
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WMOST v1 User Manual and Case Study Examples
2. Getting Started
WMOST is a screening tool for watershed management and planning. One of the envisioned
applications of WMOST is determining the least cost combination of management options to meet
management goals for a town or watershed's planning horizon. For example, the water works portion
of a town's master plan may ask, "What stormwater practices must be installed, demand management
programs created and/or infrastructure capacity constructed to meet projected human demand for the
next 20 years while meeting minimum and maximum in-stream flow targets to preserve stream
health?" To address such a planning question, all input data must correspond to the conditions
projected to occur by the end of a 20 year planning period. For example, human demand would need
to be projected 20 years from the planning year. Most of the User Guide is written from the
perspective of a user who is screening management practices to address such planning questions and
suggestions are provided throughout the User Guide and in the case study appendices for how to
specify input data appropriately. As such, the model does not provide an annual implementation plan
or specifics on operations of systems. Rather it provides the management practices and associated
costs that meet management goals at least cost and the state of the watershed and human system at the
end of the planning period if the management practices have been implemented.
2.1
Preparing for a Model Run
This section describes model specifications the user must consider prior to applying WMOST. All
data sources for the case studies are detailed in the appendices. Some of those data sources, especially
for environmental data, are state or national level and may serve as a source for your project. Most
data related to the human water system is anticipated to be available to the municipality(ies) from
their own internal sources.
Defining Hydrologic Response Units
A main input data requirement is runoff and recharge rates (RRRs) for hydrologic response units
(FiRUs)15 within the study area and the corresponding area for each HRU. These data may be derived
from a calibrated/validated simulation model such as Hydrological Simulation Program Fortran
(HSPF),16 Soil Water and Assessment Tool (SWAT)17 and/or Storm Water Management Model.18 If a
watershed simulation model is not available for the study area (e.g., from U.S. Geological Survey)
and resources do not allow for the creation and setup of a model, then the user may try using default
rates from models run for watersheds with similar characteristics. Additionally there may be generic
RRRs available from state or regional studies. Such rates would specify the HRU characteristics for
which the rates are applicable. A geographic information system can then be used to determine the
area associated with each FIRU in you study area. Future versions of the model may include default
RRRs for HRUs for various watersheds and/or ecoregions.
15
Land cover, land use, soil, slope and other land characteristics affect the fraction of precipitation that will runoff, recharge
and evapotranspire. Areas with similar characteristics - hydrologic response units (HRUs)15 - respond similarly to
precipitation.
16 http://water.usgs.gov/software/HSPF/
17 http://swat.tamu.edu/
18
http://www.epa.gov/nrmrl/wswrd/wq/models/swmm/
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In addition to a baseline set of HRUs, up to 15 "sets" of "managed" HRUs may be specified with
corresponding areas, RRRs and management costs. For HRU sets, the baseline set is used to specify
runoff and recharge rates and areas for HRUs for the baseline conditions of the model run. For
managed sets, you may specify runoff and recharge rates that reflect some form of land management
practice and the associated cost. These managed RRRs may be derived using SWMM or other
stormwater management models.
For urban HRUs, the "managed set" may reflect RRRs resulting from use of a stormwater best
management practice (e.g., bioretention basin, swales) and/or low impact development with reduced
impervious area. For agricultural HRUs, the "managed set" may reflect RRRs resulting from
implementation of edge of site or riparian buffers. For each set, you can specify the area of each HRU
on which the management practice may be implemented. Therefore, for the stormwater managed set,
you may restrict available area to urban HRUs only and vice-versa for agricultural management. In
addition, if stormwater management exists in part of the watershed, urban HRUs may be defined
separately for areas that are under management and areas that are not under management with their
respective RRRs. Then, under managed HRU sets, the new stormwater management practice may be
limited to unmanaged, urban HRUs and excluded for managed, urban HRUs (as well as other HRUs
such as agricultural or forest).
Defining the Study Area
Ideally, the study area is the entire land area draining to the stream reach of interest; however,
jurisdictional boundaries often cut across subbasins. This requires that the hydrology is modeled at
the subbasin or watershed level while management practices are limited to those areas within the
jurisdiction(s) cooperating in the management plan. The second case study of Danvers and Middleton,
MA shows the example of how to use the model in such circumstances. The first case study of the
Upper Ipswich River Basin assumes that the entire watershed is cooperating in the management
strategy such as in a water district and, therefore, management practices are specified to be available
for the entire watershed.19
Defining the Modeling Time Period
The model may be run on a daily or monthly time step. The user may choose the time step depending
on the temporal resolution of available input data, desired management practices and/or known
system behavior. For example, if stormwater management practices will be considered, a daily time
step is advised as storm events and their effects are observable on a time scale closer to a daily rather
than monthly time step. If the user desires to know the monthly or approximate water balance for
watershed or human system components, then a monthly time step would be sufficient.
The user should run the model for multiple years that cover dry, average and wet years of
precipitation. That is, time series that are input (e.g., RRRs, human demand, surface water inflow
from upstream) should include a range of potential conditions. Ensuring these specifications are met
will ensure that the management solution screened by the model will be sustainable over a range of
19 If the user wants to model multiple adjacent/downstream study areas, theoretically, the time series of surface water
outflow from the upstream study area may be used an input into the downstream study area. WMOST vl does not output
this time series in table form (only as a graph) but this functionality is listed for future development. In addition,
enhanced spatial modeling is identified as an area for future development so that all areas or reaches can be optimized
simultaneously rather than just consecutively from upstream to downstream reaches.
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WMOST v1 User Manual and Case Study Examples
potential future conditions. In addition, the user is advised to run not only a range of historical
conditions but future, projected conditions. This may be accomplished, for example, by adjusting
historical conditions for projected climate change. The EPA website "Climate Change Impacts and
Adapting to Change" describes projected changes by region.20 EPA's Climate Resilience Evaluation
and Awareness Tool provides projected changes in temperature and precipitation for climate stations
throughout the United States.21 These values may be used to adjust the detailed watershed simulation
model from which watershed time series data is obtained for WMOST (e.g., see Soil and Water
Assessment Tool climate change function) and to adjust the traditional methodology used for
projecting human demand.
Note that running WMOST with RRRs and other environmental data from a specific time period such
as 2005-2010 does not necessarily represent watershed conditions that only occurred during those
years but watershed conditions that would occur in a similar 5-year period of weather. Therefore,
these data can be adjusted for climate change or other uncertainties and re-run to determine the
sensitivity of the solution, that is, combination of management practices and costs, to potential future
deviations from historical conditions. In fact, the user is highly encouraged to perform sensitivity
analyses especially on input data with least certainty to determine the robustness of the
solution. Section 2.4 briefly describes the process for performing sensitivity analyses.
2.2 Setting Up and Running the Model
System Requirements
To open and run WMOST, you will need Microsoft Excel version 2010 installed on your computer.
The WMOST Excel file and the file for the solver, Ipsolve55.dll, must be placed in the same folder.
After opening WMOST, choose 'Enable content' or 'Enable macros' if these prompts are displayed.
When using WMOST, you may save various versions that are set up for different scenarios. You
cannot run multiple scenarios at the same time from the same folder. However, you may save a
different scenario along with the Ipsolve55.dll file in a different folder in order to run multiple
scenarios at once. Depending on your computer's specifications this may increase the run time for
each model.
If other Excel files are open while running WMOST, the Results table will have the correct values but
may not be formatted properly. Therefore, it is recommended that you do not have other Excel files
open and run model scenarios one at a time.
Finally, if you encounter software errors, please email Naomi Detenbeck at
detenbeck.naomi(g),epa.gov with the subject "WMOST bug". To register for notices of patches and
new releases, please email the same address with the subject line "WMOST register".
The User Interface-Step by Step
When you open WMOST you will see the familiar Excel interface with one worksheet called "Main".
You can navigate to input tables using the blue buttons and result table and figures using the green
buttons found on this screen. To begin entering data for your study area, start by completing input
fields on the "Main" worksheet. All input fields are blue boxes.
20 http://www.epa.gov/climatechange/impacts-adaptation/
21 http: //water, epa. go v/infrastructure/watersecuritv/climate/creat. cfm
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Case Study Examples
Please note that example screenshots and values displayed in them are from the Danvers-Middleton
case study and are not necessarily appropriate values for your study area. WMOST performs several
basic checks to ensure that input data requirements are met, for example, that price elasticies are
negative and minimum in-stream flow targets are smaller than maximum in-stream flow targets. If
these basic requirements are not met, the user is informed with a message box and asked to re-enter
the information. Section 6.1 in the Theoretical Documentation provides additional details on input
data checks and user support.
Step 1. HRUs, Areas, Runoff and Recharge. Enter the number of HRU types and HRU sets that
you intend to model. HRUs are areas of similar hydrology based on similar characteristics such as
land use, soil and/or slope. The number of HRUs will likely be determined by the diversity of these
land characteristics in your study area and your source of runoff and recharge rates. For example, a
detailed simulation model that may be available for your study area may have predefined HRUs.
INPUT DATA
1. Enter the number of HRU types kmgur study area and the number of land management options you will
| Number Of HRU Types: \\ llj [Number Of HRU Sets (baseline plus managed sets): 1 7
Step 2. Press the "Setup 1" button to automatically prepare input tables for land use, runoff and
recharge data based on your values from Step 1. The process creates blank input tables; therefore, do
not press this button again unless you have your input data saved elsewhere and want to change the
number of HRUs or HRU sets.
2. Press "Setup 1" button to prepare input tables for land use, runoff, and recharge data. Setup 1
Step 3. Here, the "Land Use", "Runoff and "Recharge" buttons will direct you to their respective
input tables:
D
Runoff
D
Recharge
Selecting the "Land Use" button directs you to the land-use input screen shown below.
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WMOST v1 User Manual and Case Study Examples
Baseline HRUs and Their Limits with Respect to Land Conservation
HRUID
HRU1B
HRU2B
HRU3B
HRU4B
HRU5B
HRU6B
HRU7B
HRUSB
HRU9B
HRU10B
HRU11B
HRU Name
Forest, sand & gravel
Open, sand & gravel
Low-resid, sand & gravel
High-resid, sand & gravel
Comm, sand & gravel
Forest, Till
Open, Till
Low-resid, Till
High-resid,Till
Forest, Fine deposition
Open, Fine deposition
Baseline
Area [acre]
1,681
437
3,099
1,274
1,255
6,660
519
7,005
1,616
110
153
Minimum
Area
[acre]
1,631
437
364
1,087
713
6,660
519
1,875
1,076
110
153
Maximum
Area [acre]
2,760
774
3,099
1,274
1,255
9,371
600
7,005
1,616
148
237
Initial Cost to
Conserve
[S/acre]
187,408
187,408
-9
-9
-9
187,408
187,408
-9
-9
187,408
187,408
O&M Cost
[$/acre/yr]
1,874
1,874
-9
-9
-9
1,874
1,874
-9
-9
1,874
1,874
In this table, you can enter data for baseline HRU conditions and costs associated with land
conservation by entering:
• names of the HRUs in your study area,
• acres of each HRU for baseline conditions,
o Note: "baseline" area can represent the existing conditions or the conditions of future
scenario that you would like to model. For example, if you intend to run the model to
prioritize management options in 2050, you would enter the projected area of each HRU
in 2050.
• "minimum" areas for each HRU - For urban HRUs this may be the existing area of urban HRUs
given that these area are not expected to be reforested or otherwise "undeveloped". For forest
lands, it may be the area of conserved/protected forest lands which must exist in the future due to
their protected status.
• "maximum" areas for each HRU - For urban HRUs, this may be the projected, build-out area or
maximum allowable area under zoning regulations. For forest lands, it may be the existing area of
forest land given that other HRU types will not be used to regrown forest for urban recreation or
start a forestry business.
• cost to conserve HRUs - For example, it may be beneficial to purchase and conserve forest or
wetlands. For these HRUs, enter the initial cost of purchasing the land (i.e., capital costs) and any
annual operations and maintenance (O&M) costs that may continue to be associated with the
purchase.
If land conservation is not possible or desirable for a HRU, then enter "-9" for initial and O&M costs.
In the above screenshot example, forest land is possible to conserve at an initial cost of $187,408 per
acre and $1,874 annual O&M costs.
Beneath the baseline HRU input table, you will see table(s) for managed HRU sets. Up to 15 sets of
"managed HRUs" may be specified with corresponding minimum and maximum areas and
associated management costs. Enter the name of the management practice in the blue box in the upper
right hand corner of the table. The rest of the table is similar to the baseline table. The following input
data are requested for each HRU:
10
-------
Case Study Examples
• minimum area on which the management practice may be implemented - For urban HRUs,
regulations may require that a specific stormwater management practice is implemented.
• maximum area on which the management practice may be implemented - For urban HRUs, some
of the HRU may already managed by the specified stormwater practice and is, therefore,
unavailable for that treatment.
• initial costs associated with the management practice - For example, design and construction of a
bioretention basin to retain one inch of runoff.
• O&M costs associated with the management practice - For example, annual clean out and other
upkeep of the bioretention basin to maintain performance.
If a management practice is not applicable or desirable for an HRU, enter "-9" for initial and O&M
costs.
< Input name of management practice
First Set of Managed Land Uses and Their Limits
HRU ID
HRU1M1
HRU2M1
HRU3M1
HRU4M1
HRU5M1
HRU6M1
HRU7M1
HRUSM1
HRU9M1
HRU10M1
HRU11M1
Land Use Name
Forest, sand &gravel
Open, sand & gravel
Low-resid, sand & gravel
High-resid, sand & gravel
Comm, sand & gravel
Forest, Till
Open, Till
Low-resid,Till
High-resid, Till
Forest, Fine deposition
Open, Fine deposition
Minimum
Area [acre]
0
0
0
0
0
0
0
0
0
0
0
Maximum
Area
[acre]
0
0
3,099
1,274
1,255
0
0
7,005
1,616
0
0
Bioretention basin, 0.6"
Initial Cost
to Manage
[S/acre]
-9
-9
3,333
5,685
12,589
-9
-9
3,S33
5,685
-9
-9
O&M Cost
[$/acre/yr]
-9
-9
38
57
126
-9
-9
38
57
-9
-9
In the above screenshot, all urban HRUs may receive bioretention management. There are no
minimum acres of HRU area that must managed but the maximum values are entered based on
projected build-out (therefore, same as maximum areas in the baseline table). In addition, as described
in the Theoretical Documentation, the maximum area of an HRU that can be managed with
bioretention is limited to the area of that HRU that exists considering land conservation decisions
(i.e., land area is conserved and no more can be treated than exists as decided is optimal by the
model). All specifications are "per acre of HRU"; therefore, the initial cost of $3,833 and O&M cost
of $38 for low density residential on sand and gravel surficial geology is the cost to treat one acre of
that HRU. The actual footprint of the bioretention basin will only be a small part of that acre of land.
If you have additional managed land use sets, repeat the same instructions for each set. Up to fifteen
stormwater management options, including traditional, green infrastructure or LID practices or other
land management practices that modify runoff and recharge may be specified. A managed set may
include multiple practices that achieve some standard such as retaining a one inch storm event using
rooftop disconnection, bioretention basins and swales.
Once this section is complete, navigate to the main screen by pressing "Return to Main":
Return to Main
11
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WMOST v1 User Manual and Case Study Examples
Check the checkbox next to "Land Use" to indicate that you have completed data entry for this
category of input. The button will become gray and help you track which input data are complete.
Next select the "Runoff button to enter time series data of runoff rates for each HRU:
Recharge
-^
Selecting "Runoff brings you
Date
(mm/dd/yyyy)
1/1/1983
1/2/1989
1/3/1989
1/4/1989
1/5/1989
1/6/1989
1/7/1989
1/S/19S9
1/9/1989
1/10/1989
1/11/1989
«* -^
to the following
Units: inches/time step
Baseline HRU Set
HRU1 HRU2
7.62E-06 1.39E-03
6.S6E-06 1.25E-03
6.19E-06 1.13E-03
5.5SE-06 1.02E-03
5.04E-06 9.15E-04
4.54E-06 S.23E-04
4.11E-06 7.41E-04
3.S9E-06 6.67E-04
3.36E-06 6.00E-04
3.01E-06 5.40E-04
2.73E-06 4.S6E-04
HRU3
6..54E-05
5.76E-05
5.07E-05
4.47E-05
3.93E-05
3.46E-05
3.05E-05
2.68E-05
2.36E-05
2.08E-05
1.83E-05
input table:
HRU4 HRU5
8.05E-05
6.93E-05
5.96E-05
5.12E-05
4.41E-05
3.80E-05
3.27E-05
2.81E-05
2.42E-05
2.08E-05
1.79E-05
2.91E-03
2.38E-03
1.95E-03
1.60E-03
1.31E-03
1.08E-03
8.84E-04
7.25E-04
5.94E-04
4.87E-04
4.00E-04
HRU6
1.7SE-03
1.60E-03
1.44E-03
1.29E-03
1.16E-03
1.05E-03
9.44E-04
S.49E-04
7.55E-04
6.BSE-Q4
6.19E-04
HRU7
1.19E-02
1.07E-02
9.65E-03
S.5SE-03
7.S1E-03
7.03E-03
6.35E-03
5.72E-03
5.15E-03
4.63E-03
4.17E-03
HRUS
7.29E-03
6.42E-03
5. 65 E- 03
4.97E-03
4.37E-03
3.85E-03
3.40E-03
3.00E-03
2.64E-03
2.32E-03
2.04E-03
HRU9
9.47E-03
8.15E-03
7.01E-03
6.03E-03
5.18E-03
4.46E-03
3.S6E-03
3.33E-03
2.86E-03
2.46E-03
2.12E-03
HRU10
1.43E-04
1.28E-04
1.15E-04
1.04E-04
9.35E-05
8.42E-05
7.58E-05
6.82E-05
6.14E-05
5.53E-05
4.98E-05
HRU11
4.26E-03
3.83E-03
3.45E-03
3.10E-03
2.79E-03
2.51E-03
2.26E-03
2.04E-03
1.84E-03
1.65E-03
1.49E-03
This table requires a time series of runoff rates for baseline and each managed land use set at the daily
or monthly time step. For a monthly time step, the day of the month does not matter. The dates
entered on sheet will populate the dates in all other input tables that require time series. Time series
data must be consecutive, that is, there must not be any missing dates. Refer to Defining Hydrologic
Response Units in Section 2.1, for discussion about data sources for runoff and recharge rates.
The time series are input vertically and HRUs and HRU sets horizontally.22 Therefore to the right of
the Baseline HRU set, you will see the continuation of the table shown below.
Managed HRU Set (HRUM1)
HRU1M1 HRU2M1 HRU3M1
7.62E-06
6.86E-06
6.19E-06
5.58E-06
5.04E-06
4.54E-06
4.11E-06
3.69E-06
3.36E-06
3.01E-06
2.73E-06
1.39E-03
1.25E-03
1.13E-03
1.02E-03
9.15E-04
8.23E-04
7.41E-04
6.67E-04
6.00E-04
5.40E-04
4.86E-G4
6.38E-05
5.61E-05
4.94E-05
4.35E-05
3.S4E-05
3.38E-05
2.97E-05
2.61E-Q5
2.30E-05
2.03 E-05
1.79E-05
HRU4M1
6.93E-05
5.96E-05
5.12E-05
4.41E-05
3. 79 E-05
3.26E-05
2.81E-05
2.42E-05
2.08E-05
1.79E-05
1.54E-05
HRU5M1 HRU6M1
1.
8,
7,
5,
4,
3,
3.
2,
2,
1.
.07E-03
,81E-04
.23E-04
,93E-04
.86E-04
,99E-04
.27E-04
,6SE-04
,20E-04
,SOE-04
1.48E-04
1.7SE-03
1.60E-03
1.44E-03
1.29E-03
1.16E-03
1.05E-03
9.44E-04
8.49E-04
7.65E-04
6.8SE-04
6.19E-04
HRU7M1
1.19E-02
1.07E-02
9.65E-03
8.6SE-03
7.81E-03
7.03E-03
6.35E-03
5.72E-03
5.15E-03
4.63E-03
4.17E-03
HRUSM1
7.11E-03
6.26E-03
5.51E-03
4.85E-03
4.26E-03
3.75E-03
3.31E-03
2.92E-03
2.57E-03
2.26E-03
1.99E-03
HRU9M1
8.15E-03
7.01E-03
6.03 E-03
5.18E-03
4.46E-03
3. 83 E-03
3.32E-03
2.S6E-03
2.46E-03
2.12E-03
1.82E-03
HRU10M1 HRU11M1
1.43E-04
1.28E-04
1.15E-04
1.04E-04
9.35E-05
8.42E-05
7.58E-05
6.82E-05
6.14E-05
5.53E-05
4.9SE-05
4.26E-03
3.83E-03
3.45E-03
3.10E-03
2.79E-03
2.51E-03
2.26E-03
2.04E-03
1.84E-03
1.65E-03
1.49E-03
22 If an HRU is excluded from a "managed set" then the values specified are not consequential as the model will exclude
using those values.
12
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Case Study Examples
Once you have entered these data, select "Return to Main" and check the box indicating that this
section is complete.
Next select the "Recharge" button to enter time series data of recharge rates for each HRU:
Runoff D[ Recharge
Date Baseline HRU Set (HRU)
(mm/dd/yyyy) HRU1 HRU2 HRU3 HRU4 HRU5 HRU6 HRU7 HRUS HRU9 HRU10 HRU11
1/1/1989
1/2/19S9
1/3/19S9
1/4/19S9
1/5/1985
1/6/1989
1/7/19S9
1/8/19S9
1/9/1988
1/10/19S9
1/11/19S9
2.2E-02
2.2E-02
2.2E-02
2.1E-02
2.1E-02
2.1E-02
2.1E-02
2.1E-02
2.0E-02
2.0E-02
2.0E-02
5.2E-02
5.1E-02
5.0E-02
4.9E-02
4.8E-02
4.7E-02
4.6E-02
4.5E-02
4.5E-02
4.4E-02
4.3E-02
3.4E-02
3.4E-02
3.3E-02
3.2E-02
3.1E-02
3.1E-02
3.0E-02
3.0E-02
2.9E-02
2.9E-02
2.SE-02
3.4E-02
3.3E-02
3.2E-02
3.1E-02
3.0E-02
3.0E-02
2.9 E- 02
2.8E-02
2.8E-02
2.7E-02
2.7E-02
3.2E-02
3.1E-02
3.0E-02
2.9E-02
2.SE-02
2.7E-02
2.6E-02
2.6E-02
2.5E-02
2.4E-02
2.3E-02
1.2E-02
1.2E-02
1.2E-02
1.2E-02
1.2E-02
1.1E-02
1.1E-02
1.1E-02
1.1E-02
1.1E-02
1.1E-02
2.8E-02
2.SE-02
2.7E-02
2.7E-02
2.6E-02
2.6E-02
2.5E-02
2.5E-02
2.5E-02
2.4E-02
2.3E-02
2.1E-02
2.0E-02
2.0E-02
1.9E-02
1.9E-02
1.9E-02
1.8E-02
1.8E-02
l.SE-02
1.7E-02
1.7E-02
1.9E-02
1.8E-02
1.8E-02
1.8E-02
1.7E-02
1.7E-02
1.7E-02
1.6E-02
1.6E-02
1.6E-02
1.5E-02
1.6E-02
1.5E-02
1.5E-02
1.5E-02
1.4E-02
1.4E-02
1.4E-02
1.4E-02
1.3E-02
1.3E-02
1.3E-02
3.8E-02
3.6E-02
3.5E-02
3.4E-02
3.3E-02
3.2E-02
3.1E-02
3.1E-02
3.0E-02
2.9E-02
2.SE-02
Similar to the runoff input table, the recharge input table also requires a time series of recharge rates
for baseline and each managed land use set at the daily or monthly time step. Similarly, it should be
consecutive and complete.
Managed HRU Set (HRUM1)
HRU1M1 HRU2M1 HRU3M1 HRU4M1 HRU5M1 HRU6M1 HRU7M1 HRUSM1 HRU9M1 HRU10M1 HRU11M1
2.2E-02
2.2E-02
2.2E-02
2.1E-02
2.1E-02
2.1E-02
2.1E-02
2.1E-02
2.0E-02
2.0E-02
2.0E-02
5.2E-02
5.1E-02
5.0E-02
4.9E-02
4.8E-02
4.7E-02
4.6E-02
4.5E-02
4.5E-02
4.4E-02
4.3E-02
3.4E-02
3.3E-02
3.2E-02
3.1E-02
3.1E-02
3.0E-02
3.0E-02
2.9E-02
2.SE-02
2.8E-02
2.7E-02
2.9E-02
2.8E-02
2.7E-02
2.7E-02
2.6E-02
2.5E-02
2.8E-02
2.6E-02
2.4E-02
2.3E-02
2.3E-02
1.2E-02
1.2E-02
1.1E-02
1.1E-02
l.OE-02
l.OE-02
2.2E-02
1.7E-02
9.3E-03
S.9E-03
8.6E-03
1.2E-02
1.2E-02
1.2E-02
1.2E-02
1.2E-02
1.1E-02
1.1E-02
1.1E-02
1.1E-02
1.1E-02
1.1E-02
2.SE-02
2.8E-02
2.7E-02
2.7E-02
2.6E-02
2.6E-02
2.5E-02
2.5E-02
2.5 E- 02
2.4E-02
2.3E-02
2.0E-02
2.0E-02
1.9E-02
1.9E-02
1.8E-02
1.8E-02
l.SE-02
l.SE-02
1.7E-02
1.7E-02
1.7E-02
1.6E-02
1.6E-02
1.6E-02
1.5E-02
1.5E-02
1.5E-02
1.7E-02
1.6E-02
1.4E-02
1.4E-02
1.3E-02
1.6E-02
1.5E-02
1.5E-02
1.5E-02
1.4E-02
1.4E-02
1.4E-02
1.4E-02
1.3E-02
1.3E-02
1.3E-02
3.SE-02
3.6E-02
3.5E-02
3.4E-02
3.3E-02
3.2E-02
3.1E-02
3.1E-02
3.0E-02
2.9E-02
2.SE-02
Select "Return to Main" and check the box indicating that this section is complete.
Step 4. Water Users, Water Demand, Demand Management and Septic System Use. On the
Main page, enter the number of water user types. Do not include unaccounted-for-water as it is
automatically included in all relevant input tables.
Number of Water UserTypes:
Step 5. Press the "Setup 2" button to automatically prepare input tables for potable, nonpotable,
demand management, and septic components of your system. The process creates blank input tables;
13
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WMOST v1 User Manual and Case Study Examples
therefore, do not press this button again unless you have your input data saved elsewhere and want to
change the number of water user types.
5. Press "Setup 2" button to prepare input tables for potable and nonpotable demand and septic systems data
Setup 2
Step 6. The "Potable", "Nonpotable" and "Demand Management", and "Septic" buttons will direct
you to input tables relating to these input data categories:
n
Nonpotable
Demand
D
Demand
Management
n
Septic Systems
Selecting "Potable" will lead you to the following input table:
Date Total Water Demand [million gallons /time step]
(mm/dd/yyyy) Unaccounted Residential Commercial Agricultural Industrial Municipal
1/1/1989
1/2/1989
1/3/1989
1/4/1989
1/5/1989
1/6/1989
1/7/1989
1/8/1989
1/9/1989
1/10/1989
1/11/1989
0.199
0.199
0.199
0.199
0.199
0.199
0.199
0.199
0.199
0.199
0.199
1.937
1.937
1.937
1.937
1.937
1.937
1.937
1.937
1.937
1.937
1.937
0.882
O.S82
O.SS2
0.882
0.882
0.882
0.882
0.882
0.882
0.882
0.882
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.005
0.008
0.008
0.008
o.oos
0.008
0.008
0.008
0.008
0.008
0.008
0.008
0.333
0.333
0.333
0.333
0.333
0.333
0.333
0.333
0.333
0.333
0.333
This table requires a time-series of the potable water demand for all users entered in Step 4, plus
demand attributable to unaccounted-for-water. This time series should be 1) at the time step of your
model, that is, the same time step as runoff and recharge rates, 2) complete and consecutive and 3) the
exact same time period as the runoff and recharge rate data.
This section also includes an input table for the average percent consumptive water use by month.
These values can reflect any seasonal changes in consumptive use over the year, such as increased
outdoor watering in the summer, and among water user types.
Water withdrawal and demand and consumptive use data may be available from state or regional
sources. For example, in Massachusetts the Department of Environmental Protection receives such
data in the form of Annual Statistical Reports from water utilities.
14
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Case Study Examples
Average Percent Consumptive Water Use (%)
Month Residential Commerci Agricultural Industrial Municipal
January
February
March
April
May
June
July
August
September
October
November
December
4
4
4
6
20
26
29
25
20
4
4
4
4
4
4
6
20
26
29
25
20
4
4
4
99
99
99
99
99
99
99
99
99
99
99
99
4
4
4
6
20
26
29
25
20
4
4
4
4
4
4
6
20
26
29
25
20
4
4
4
Note: None of these columns or rows need to add to 100%. Each value is the
percent consumptive use for a user type for a month.
Select "Return to Main" and check the box next to the "Potable" button when this section is complete.
Clicking on the "Nonpotable" button will bring you to the following input tables where percent
nonpotable water use by user type and percent consumptive nonpotable water use can be filled in with
site-specific data. The percent nonpotable water is the maximum amount of potable use that may be
met using nonpotable water such as toilet flushing or outdoor irrigation.
The values in the columns or rows do not need to add to 100% for either table.
Maximum Potential Nonpotable Water Use (%)
Month Residential Commercial Agricultural Industrial Municipal
January
February
March
April
May
June
July
August
September
October
November
December
45
45
45
45
45
45
45
45
45
45
45
45
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
99
99
99
99
99
99
99
99
99
99
99
99
90
90
90
90
90
90
90
90
90
90
90
90
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WMOST v1 User Manual and Case Study Examples
Average Percent Consumptive Nonpotafole Water Use [%)
Month Residential Commercial Agricultural Industrial Municipal
January
February
March
April
May
June
July
August
September
October
November
December
1
1
1
3
17
23
26
22
17
1
1
1
1
1
1
3
17
23
26
22
17
1
1
1
99
99
99
99
99
99
99
99
99
99
99
99
4
4
4
6
20
26
29
25
20
4
4
4
1
1
1
3
17
23
26
22
17
1
1
1
Based on these nonpotable input data, the consumptive use percent of potable water is recalculated. It
is possible to enter values for Maximum Potential Nonpotable Water Use and Average Percent
Consumptive Nonpotable Water Use that result in Adjusted Consumptive Potable Water Use values
that are outside of the feasible range of 0-100%. To help the user confirm that nonpotable input data
do not create infeasible Adjusted Consumptive Potable Water Use values, a third table on the
"Nonpotable Demand" worksheet pre-calculates these adjusted values (see below). If any of the
values are outside of the feasible range, they are highlighted red. In addition, the model will not run
and the user is provided with an error message to change input values for Maximum Percent
Nonpotable Use and/or Average Percent Consumptive Nonpotable Water Use. Therefore, ensure that
values are not highlighted red in the table shown below before proceeding.
Adjusted Consumptive Potable Water Use (%)
Month Residential Commercial Agricultural Industrial Municipal
January
February
March
April
May
June
July
August
September
October
November
December
6
6
6
a
22
28
31
27
22
6
6
6
31
31
31
33
47
53
56
52
47
31
31
31
99
99
99
99
99
99
99
99
99
99
99
99
4
4
4
6
20
26
29
25
20
4
4
4
31
31
31
33
47
53
56
52
47
31
31
31
Select "Return to Main" and check the box next to the "Nonpotable" button when this section is
complete.
16
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Case Study Examples
Click on the "Demand Management" button to enter information about how changes in price and
other demand management practices may affect demand in your study area.
The first option is reducing demand by increasing the price of water services. Specify the price
elasticity - percent change in water use divided by percent change in price - for each type of water
user. Price elasticities should be negative given that an increase in price is expected to decrease water
use. Price elasticities may be found in the literature but will depend on existing pricing and other local
conditions.23 For example, if the consumer's purchase price of water is relatively high, price
elasticities will be smaller than if the existing pricing if relatively low. This reflects the fact that
increasing price indefinitely will not decrease demand indefinitely; therefore, it is not a linear effect.
The user may specify the maximum price change possible within the planning horizon which may be
used to limit price change over the range where the response is expected to be linear.24
Price Elasticities [% demand reduction / % price increase]
Residential Commercial Agricultural Industrial Municipal
-0.2
-0.2
-0.5
-0.1
-0.2
Initial cost
Q&M cost
Maximum price change
23,000
2,000
20
$
$/yr
%
Maximum percent increase in price of water services from existing price overthe duration of the planning horizon
The initial cost may reflect the cost of a study to determine effective pricing structure and values,
billing frequencies, changes in billing logistics, and consumer outreach to convey the importance of
efficient use of water resources and the planned change in pricing. O&M costs may reflect smaller
studies to re-evaluate pricing every year or five years; however, be sure to enter the expected annual
cost of such evaluations.
The second option is direct demand reductions which may be achieved using rebates for water
efficient appliances, changing building codes, educational outreach and other practices. Initial and
O&M costs may be specified for the aggregate cost of direct demand reduction practices. The
aggregate effect of these practices should be specified as a percent reduction is overall demand.
Initial cost
O&M cost
Total demand reduction
3,136,600
0
0.60
$
$/yr
MGD
Total demand reduction value should equal the MGD reduction in demand across all
usertypes achieved by all managemnet practices encompassed in the initial and
O&M cost.
EPA's WaterSense website provides a calculator that together with local or Census data (e.g., number
of households) can be used to determine the total potential reductions in water use with the
For example, http://www.hks.harvard.edu/fs/rstavins/Monographs_&_Reports/Pioneer_Olmstead_Stavins_Water.pdf
24 The effect of price on water is assumed to be linear with WMOST vl but nonlinear assumption may be implemented in
future version.
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WMOST v1 User Manual and Case Study Examples
installation of water efficient appliances.25 When acquiring input data for these practices, the user
must be aware of the potential reduction in the individual effectiveness of demand management
practices when multiple practices are implemented simultaneously.26
For any options that are not possible or desirable, enter -9 for costs.
Select "Return to Main" and check the box next to "Demand Management" when this section is
complete.
Click on the "Septic" button to enter information about the percent of customers with septic systems
inside and outside of your study area that are on public water. Customers that are not on public water
should be represented as private withdrawals and discharges on the Surface Water or Groundwater
input worksheets depending on their source and discharge of water (see Step 7 below for description
of these input worksheets).
For public water users, it is important to distinguish customers who are on septic systems but are
outside of the watershed of the study area being modeled. Such septic systems do not recharge the
groundwater and do not contribute to the baseflow of the stream in the study area's watershed.
Customers with Public Water &
Residential Commercial
9.4 9.4
Customers with Public Water a
Residential Commercial
Septic Systems
Agricultural
Recharging Inside Study Area (%)
Industrial
9.4
Septic Systems
Agricultural
Municipal
9.4 9.4
Recharging Outside Study Area (%)
Industrial
Municipal
00000
Select "Return to Main" and check the box next to "Septic" when this section is complete.
Step 7. Surface Water, Groundwater, Interbasin Transfer and Infrastructure. Here you will see
buttons which will bring you to the Surface Water, Groundwater, Interbasin Transfer, and
Infrastructure input tables:
D
Surface Water Q
81 In-Stream
Flow Targets
Groundwater
Interbasin
Transfer
I—I Infrastructure
Clicking on the "Surface Water" button will bring you to three input tables.
In Part 1 of this section, you can enter reservoir or surface storage properties and costs. Reservoir and
surface storage may represent reservoirs, lakes or ponds used for water supply and/or surface storage
tanks. Surface storage in wetlands may be modeled as surface storage or as a separate HRU. Initial
http://www.epa. gov/watersense/our_water/start_saving.html#tabs-3
26 For example, rebates for water low flow shower heads will reduce the gallons per minute used in showering. If an increase
in water rates is implemented at the same time, the anticipated water use reduction may not be as large with a low flow
shower head as with a high flow shower head even if the new water rates induce shorter shower times.
18
-------
Case Study Examples
volume is the volume at the start of modeling period. Minimum target volume may represent the
volume of water always maintained in storage for emergencies or inactive storage volume which is
inaccessible due to the height of the storage outlet. Existing maximum volume is the total volume of
existing storage. Initial costs should include the cost to plan, design and build additional surface
storage volume. O&M costs should include the annual cost for maintaining surface storage capacity
in operational condition.
Initial reservoir/surface storage volume
Minimum target reservoir/storage volume
Existing maximum reservoir/storage volume
Initial construction cost
O&M costs
533
0.0
710
1,542,790
0
[MG]
[MG]
[MG]
[$/MG]
[$/MG]
To exclude an increase reservoir/surface storage volume as a management option, enter -9 in the input
field shown below.
Exclude New/Additional - to exclude new and
additional capacity for a surface water storage, enter -9
In Part 2 you may enter information about private withdrawals and discharges of surface water such
as industrial users that are not on public water. These data may be available from state sources such as
the Department of Environmental Protection or regional sources such as regional EPA offices. In
addition, if the stream into which your study area drains receives inflow from an upstream reach,
enter a time series for the inflow of this surface water. These data should be available from the model
from which you may have obtained your RRRs. These time-series must be at the resolution of your
model (i.e., daily or monthly) and over the same time period as other time series. The dates will be
pre-filled for you based on data you entered in the Runoff tab. As with other time series data, they
must be complete and consecutive. For any of the three time series, if you do not have data or they do
not exist, enter zero for all dates. Note that upstream inflow is critical, especially if you will be
specifying any streamflow requirements.
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WMOST v1 User Manual and Case Study Examples
For withdrawals and discharges that do not exist, enter 0.
Private Sw Private Sw
Date Withdrawal Discharge External Sw
(mm/dd/yyyy} [MG/time step] [MG/time step] Inflow [cfs]
1/1/1989
1/2/1989
1/3/1989
1/4/1989
1/5/1989
1/6/1989
1/7/1989
1/8/1989
1/9/1989
1/10/1989
1/11/1989
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
19.91
18.60
17.80
17.09
16.23
15.53
14.92
14.42
13.92
13.31
12.60
In Part 3 you may provide management goals for minimum and/or maximum in-stream flow on a
monthly basis. In addition, any requirements for flow to a downstream reach may be specified.
Requirements or guidelines for minimum and/or maximum in-stream flow may be found at the state
or regional level. For example, in New England there are Stream Flow Recommendations27 and in
Massachusetts there is a Sustainable Water Management Initiative Framework.28 If any of these flow
requirements do not exist in your study area, enter "-9" for each month of that set.
27 http://www.fws.gov/newengland/pdfs/Flowpolicy.pdf
28 http://www.mass.gov/eea/docs/eea/water/swmi-framework-no v-2012.pdf
20
-------
Case Study Examples
For minimum and maximum values, enter -9 and the model will not apply the constraint
Month
Minimum In- Minimum Sw
Stream Flow Maximum In- Outflowto
[cfs] stream flow [cfs] External Sw [cfs]
January
February
March
April
May
June
July
August
September
October
November
December
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
-9
Select "Return to Main" and check the box next to "Surface Water" when this section is complete.
Clicking on the "Groundwater" button will direct you to three input tables.
As in the Surface Water section, the Groundwater input tables consist of three parts. The same state
and regional data sources are recommended as for surface water data. In Part 1, enter information
about groundwater storage characteristics will likely be derived from the same model that you obtain
the runoff and recharge rates. These data include:
• groundwater recession coefficient or baseflow coefficient - fraction of groundwater volume that
flows to the stream reach each time step,
• initial groundwater volume - volume of the active groundwater aquifer at the start of the
modeling period,
• minimum volume - this volume may be based on the depth of wells which are used for water
supply below which water is inaccessible and/or the volume at which the water table will be
below the stream bed and therefore no longer emptying to the stream, and
• maximum volume - this value represents the total storage capacity of the aquifer.
Groundwater recession coefficient
Initial groundwater volume
Minimum volume
Maximum volume
0.01
1,134
706
2,83S
[I/time step]
[MG]
[MG]
[MG]
In Part 2, similar to the Surface Water tab, you can enter time series data for private groundwater
withdrawals, discharges and inflow into the study area.
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WMOST v1 User Manual and Case Study Examples
For withdrawals and
discharges that do not exist, enter 0.
Private Gw Private Gw External Gw
Withdrawal Discharge Inflow
Date [MG/time [MG/time [MG/time
[rnm/dd/yyyy] step] step] step]
1/1/1989
1/2/1939
1/3/1989
1/4/1989
1/5/1989
1/6/1989
1/7/1989
1/8/1989
1/9/1989
1/10/1989
1/11/1989
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
In Part 3, similar to the Surface Water tab, you can enter requirements for groundwater flowing out of
the basin. In most cases this will not exist as the groundwater will drain to the stream reach; however,
this option provides flexibility in defining a study area or when groundwater and surface water
watersheds do not overlap.
For minimum and maximum values, enter -9 and the model will not apply the constraint
Month
January
February
March
April
May
June
July
August
September
October
November
December
Minimum External
Gw Outflow
[MG/time step]
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
Select Return to Main and check the box next to "Groundwater" when this section is complete.
Clicking the "Interbasin Transfer" (IBT) button will lead you to the two sets of input data.
22
-------
Case Study Examples
In Part 1, you can enter data for:
• costs to purchase water and wastewater from systems outside of your study area and
• initial costs for water and wastewater rights in addition to any existing agreements including costs
for any new infrastructure to utilize the additional rights.29
If you do not want IBT as a management option, enter-9 for costs AND Of or constraints.
Purchase cost for potable water
Purchase cost for wastewater
3,803
6,340
[S/MG]
[S/MG]
Initial cost for new/increased IBT potable water limit
Initial cost for new/increased IBT wastewater limit
29,500,000
0
[$/MGD]
[$/MGD]
In Part 2, enter any existing monthly limits for interbasin transfer of water and wastewater in the left
and daily or annual limits in the right table. Depending on the time step of your model, the daily,
monthly and/or annual limits are adjusted to specify appropriate constraints in the model.
Enter existing limits on IBT for daily, monthly and/or annual basis. If a constraint does not exist, enter -9.
Existing Limits on IBT [MG per month]
Month Water Wastewater
January
February
March
April
May
June
July
August
September
October
November
December
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9:00
-9.00
-9. '00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
-9.00
Existing Limits on IBT
Daily [MGD]
Annual [MG peryear]
Water
-9.00
-9.00
Wastewater
6.00
-9.00
Additional Capacity Limits
Daily [MGD]
Water
0.27
Wastewater
-9.00
The following guidelines for specifying limits and initial costs for increasing limits are
important to note:
• If you do not have interbasin transfer as an option, you must enter "0" for limits. Entering "•
9" will indicate no restriction, that is, unlimited interbasin transfer is available. As such if you
enter -9 for daily, monthly or annual limits, then you must specify the initial cost for
new/increased IBT.
• If additional water or wastewater services can be purchased with no additional initial costs or
entry fees, then enter the current agreement limit for services and specify $0 for initial cost
for a new/increased limit (i.e., do not enter -9 for the existing limit).
1 The second case study of Danvers and Middleton, MA provides costs associated with initial connection for water with the
Massachusetts Water Resources Authority, a large regional water and wastewater provider.
23
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WMOST v1 User Manual and Case Study Examples
• If your system provides water services to customers outside of the basin without a return flow via
the wastewater treatment plant or septic systems, you may specify these customers as a separate
water user type that entirely drains to septic outside of the study area. If your system provides out
of basin wastewater services that discharge in your basin, you may enter this flow as a private
discharge of surface water (or groundwater, depending on where the wastewater treatment plant
discharges). WMOST vl does not support routing out of basin wastewater to the wastewater
treatment plant. It may be added as functionality in future versions.
• If your system's wastewater is treated outside of the basin at a larger, central facility and you
want to model returning the treated wastewater for discharge locally, then you may enter a capital
cost for a wastewater treatment plant that represents the construction of infrastructure necessary
to return and discharge the treated wastewater. In addition, enter O&M costs that reflect the IBT
O&M cost and exclude the use of IBT for wastewater. This will effectively model the desired
scenario. If the returned wastewater will be discharged to groundwater rather than surface water,
follow the same procedure but apply it to the aquifer storage and recharge facility rather than the
wastewater treatment plant. See below under "Infrastructure" for input data tables related to
wastewater treatment plant and aquifer and storage recharge facility.
Select "Return to Main" and check the box next to "Interbasin Transfer" when this section is
complete.
Clicking "Infrastructure" will lead you to the next section, where you can add information about costs
and capacity limits for a range of water and wastewater facilities. This section consists of six parts.
In Part 1, you enter the planning horizon for large capital improvement projects and the interest rate
for loans for such projects. For any management option for which a project lifetime is not requested,
the planning horizon is used for the lifetime over which the initial cost is annualized. The specified
interest rate is used for the annualization of all initial and capital costs. For mathematical equations
describing the annualization of capital costs, please refer to Section 2.1.1 in the separate Theoretical
Documentation.
Planning horizon [years]
Interest rate [%]
20
5.00
In Part 2, you enter data related to providing water services including:
• Consumer's price for potable water - this may be specified as a monthly fixed fee and/or volume
based fee,
• Facility data for groundwater pumping, surface water pumping and water treatment plant
including
o Capital costs - cost for increasing capacity or cost for replacing existing capacity beyond
the remaining lifetime,
o O&M costs - cost for operating based on the size and flow through the facility,
o Existing maximum capacity of the facility,
o Lifetime remaining on existing infrastructure or the number of years expected to remain
before major capital rehabilitation or new facility must be built, and
24
-------
Case Study Examples
o Lifetime of new infrastructure - the expected lifetime of new construction before major
capital rehabilitation or new facility must be built,
• Potable distribution system data including
o Initial cost for surveying the distribution system for leaks and repairing to the maximum
percent feasible,
o O&M costs representing annual costs for maintaining repairs made to the distribution
system, and
o Maximum percent of distribution system leaks that can be fixed - this value may be less
than 100% due to practical limitations of many miles of pipes.
If no water treatment plant exists in your study area (i.e., all water is from interbasin transfer), then
enter "0" for maximum capacities and remaining lifetimes. However, still enter the price that is
charged for customers for water services. To exclude the option to increase facility capacity, enter -9
in the "Exclude New/Additional" for the appropriate facility.
Water services
Value
Units
Exclude New/Additional
Consumer's price for potable water: Fixed fee
Consumer's price for potable water: Variable, volume-based fee
0
5.03
S/month
S/HCF
Groundwater (Gw) Pumping
Capital cost for additional capacity
747,285
Operation & Maintenance (Q&M) costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
1.74
33
35
S/MGD
S/MG
MGD
yrs
yrs
Surface Water (Sw) Pumping
Capital cost for additional capacity
453,885
O&M costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
9.40
33
35
S/MGD
S/MG
MGD
yrs
yrs
Water Treatment Plant (WTP)
Capital cost for additional capacity
O&M costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
2,022,884
5,314
9.40
33
35
S/MGD
S/MG
MGD
yrs
yrs
Unaccounted-for-Water/ Potable water distribution system leak
Initial cost for survey & repair
O&M costs for maintaining reduction in UAW
Maximum percent UAW that can be fixed
774,368
77,437
99
S
S/yr
%
0
0
0
In Part 3, enter similar data for wastewater services as for water services including consumer's price,
capital and O&M costs, lifetime of new and existing infrastructure, and repair of infiltration into
collection system. Two additional data are requested:
• "Are wastewater fees charged based on metered water or wastewater?" -Most wastewater utilities
in the U.S. charge for wastewater services based on metered potable water delivered to a
customer. However, the option is provided to charge based on metered wastewater determine the
effect of separating metering.
• "Existing Gw infiltration into collection system" - Specify the percent of wastewater inflow to
the wastewater treatment plant that is groundwater infiltration.
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WMOST v1 User Manual and Case Study Examples
Wastewater treatment plant (WWTP)
Consumer's price for wastewater services: Fixed fee
Consumer's price for wastewater services: Variable, volume-based fee
Are wastewater fees charged based on metered water or wastewater?
Capital cost for additional capacity
O&M costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
Value Units Exclude New/Additional
0.00
6.12
water
15,788,674
7,925
0.00
0
40
S/month
S/HCF
water or wastewater
S/MGD
S/MG
MGD
years
years
Infiltration into wastewater collection system
Existing Gw infiltration into collection system
Initial cost for survey & repair
O&M costs for maintaining reduction in infiltration
Maximum percent of infiltration that can be fixed
0
214,846
21,485
0
% of WW Inflow
s
S/yr
%
0
To exclude the option to increase wastewater treatment plant capacity, enter -9 in the "Exclude
New/Additional" data field.
In Part 4, enter data for a water reuse facility (WRF) similar to water and wastewater facilities
including the ability to exclude new and additional capacity.
Water Reuse Facility (WRF) Value Units Exclude New/Additional
Capital cost for additional/ new capacity
O&M costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
10,402,467
2,850
0.00
0.00
35
S/MGD
S/MG
MGD
yrs
yrs
0
In Part 5, enter data for a nonpotable water distribution system which are similar to the other facilities
but in addition, specify the price that would be charged to customers for the provision of nonpotable
water. See case study appendices for potential data sources.
Nonpotable Water Distribution System
Value
Units
Exclude New/Additional
Consumer's pricefor nonpotable water: Fixed fee
Consumer's pricefor nonpotable water: Variable, volume-based fee
Capital cost for additional capacity
O&M costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
0
3.02
12,529,440
1,716
0.00
0
35
S/month
S/HCF
S/MGD
S/MG
MGD
yrs
yrs
0
In Part 6, enter data for an aquifer storage and recovery (ASR) facility similar to the other facilities.
Aquifer Storage and Recovery (ASR) Value Units Exclude New/Additional
Capital cost for additional/new capacity
O&M costs
Existing maximum capacity
Lifetime remaining on existing infrastructure
Lifetime of new construction
10,807,824
3,769
0
0
35
S/MGD
S/MG
MGD
yrs
yrs
0
Select "Return to Main" and check the box next to "Infrastructure" when this section is complete.
Step 8. Measured In-stream Flow. Click on the "Measured Flow" button to lead you to the next
input table. These data are used to create an output graph showing both measured and modeled in-
stream flow to assess the accuracy of the model in reproducing measured flows. These data may be
26
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Case Study Examples
acquired from the U.S. Geological Survey or from the model from which you may have obtained
RRRs.
Date (mm/dd/yyyy) Measured In-Stream Flow (cfs)
1/1/1989 25.66
1/2/1989 26.77
1/3/19S9 26.27
1/4/1989 25.06
1/5/1989 23.90
1/6/1989 22.79
1/7/1989 21.63
1/8/1989 20.72
1/9/1989 19.91
1/10/1989 19.06
1/11/1989 18.10
Select "Return to Main" and check the box next to "Measured Flow" when this section is complete.
Once all sections are complete, you may run the optimization model by clicking the red "Optimize"
button. This will initiate the optimization and processing of results.
RUN OPTIMIZATION
Optimize
Once the optimization is complete, the model will display the message below. Click "OK" and wait
for the model to process outputs and populate the Results tables. The Main page will display again
once the output processing is complete.
Optimization complete!
OK
2.3 Evaluating Results
After optimization, WMOST provides three outputs:
1. summary table of management practices and associated costs that met specified goals (e.g.,
minimum demand, minimum in-stream flow) at least cost,
2. graph of modeled in-stream flow and baseflow compared with user-specified measured in-stream
flow, and
3. modeled in-stream flow and baseflow and user-specified minimum and/or maximum in-stream
flow targets.
27
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WMOST v1 User Manual and Case Study Examples
Results represent estimated conditions at end of the planning horizon if all management practices
were implemented. For example, the modeled in-stream flow and baseflow are estimated to occur if
recommended management practices are implemented and human demand is at the projected rate
input by the user with the expected weather patterns (i.e., user input runoff and recharge rates). The
flows over the modeling period represent estimated flow over a variety of potential weather
conditions represented by the years in the modeling period. The length of the modeling period and the
variety of conditions it represents determines the robustness and sustainability of the solutions
recommended by the model. In addition, performing sensitivity analyses is highly recommended
especially for input data with least certainty to further determine the robustness of results. By varying
the input data, you can determine the robustness of results over a variety of potential conditions that
may occur by the end of planning period.
To view the summery table of results, select the "Results Table" button to display the management
decisions and associated costs. Capital and O&M costs are presented as one total annualized cost in
WMOST vl. This may lead to costs for an existing facility even if no additional capacity is selected
as a management practice. For example, an existing water treatment plant may be able to meet
projected demand without additional capacity but O&M costs are still incurred for operating the
facility for the required demand. Therefore, when "number of units" is zero but there is still a cost,
that cost represents O&M costs.
Results Table
An excerpt from the summary table of results is below:
RESULTS
Due to solver precision, there mav be neglible changes in HRU areas that round to zero displaved asO or (0).
Total Annual Cost
Water Revenue
Wastewater Revenue 310.3 million
:MANAGE:MEXT PRACTICES
Number of Units
Total Annual Sub-Costs (incl. O&M)
Demand Management
Consumer Rate Change a o
Direct Demand Reduction
MGD
Land Conservation
Forest, sand & gravel
Open, sand & gravel
Low-resid, sand & gravel
High-residj sand & gravel
Acie;
Acre;
Acre;
Acre;
Select the "Compare to Measured Flow" button to display a graph comparing measured in-stream
flow to modeled in-stream flow and baseline.
ME
Compare to
Measured Flow
Select the "Compare to Target Flow" button to display a graph comparing modeled flows to user-
specified in-stream flow constraints.
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Case Study Examples
Compare to
Target Flow
Results may be printed from the Excel interface with the same options as any Excel file or copied and
pasted into Word or another application.
2.4 User Tips
The following tips are provided for troubleshooting, interpreting results and modeling specific
situations or scenarios.
• If the results show "1E+30" for Total Annual Cost, the scenario run was infeasible. This means
that the specified management goals and/or continuity constraints could not be met with the user-
provided input data. Refer to the Theoretical Documentation for constraints that are defined in the
optimization model. You may need to adjust your management goals or identify erroneous input
data. Future versions of the model will support identifying constraints and data that contribute to
infeasible solutions.
• If you want to test the effect of a management option but the model is not selecting it, you can
enter 0 for cost. You can also adjust the cost of a management practice to see the cost at which
that practice is selecting by the model and, therefore, assessed as cost effective.
• To exclude replacement costs for existing infrastructure, set the remaining lifetime to be greater
than the planning period. This tells the model that the infrastructure does not need replacement
within the planning period and the model will not calculate replacement costs. It will only
calculate capital costs for new or additional capacity of infrastructure and O&M costs.
• As detailed in the Theoretical Documentation, a "sustainability" constraint forces the initial and
final groundwater and reservoir/surface water storage volumes to be equal. If only one year is
modeled, then the watershed should be a "within-year" watershed, that is, the groundwater and
reservoir volumes generally return to their initial levels each year. If multiple years are modeled,
this sustainability constraint "softens" and the model may be applied to multi-year watersheds as
well.
• A "simulation run" is advised before optimization runs to determine the accuracy of WMOST in
modeling in-stream flow relative to measured data or data from the detailed watershed simulation
model from which RRRs may have been acquired. Section 3.2.2 describes the process for
performing a "simulation run" with WMOST.
• Sensitivity analyses should be performed with the most uncertain input data. For example, if the
price elasticity for industrial water use is most uncertain, then the model should be run multiple
times over a range of potential values as follows:
1. Starting with the best estimated value, determine the range of potential values e.g., -0.5
with a potential range of-0.2 to -0.7.
2. Run the model with the same input data varying only the price elasticity for industrial
water use. For example, run the model five times with values of-0.2, -0.3, -0.5, -0.6, and
-0.7.
29
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WMOST v1 and
3. Save the results of each run, that is, either use the "save as" function in Excel to save a
different version of the file/model with each run or copy and paste the results tables into a
separate Excel file.
4. Determine the effect of the price elasticity on results. Does it change whether demand
management via pricing is implemented? Does it change the mix of other management
options? How does it change the total annual cost?
Ideally, change only one of the input data at a time at first so that you can determine the
individual effect of each variable. Once you know the individual effects and you have more than
one uncertain input data, you may want to run the model varying more than one data at a time to
determine their combined effects. You may consider "worst" and "best" case scenarios. For
example, vary all uncertain data in the direction of higher costs to determine the worst case
scenario for total cost if all uncertain data were to be truly in the higher cost direction. Or run the
highest cost for a specific management practice to determine the whether it is still a cost effective
practice that is chosen by the model and, therefore, a "no regrets" option. For more guidance,
please refer to EPA's "Sensitivity and Uncertainty Analyses" website.30
Trade-off analyses are similar to sensitivity analyses but with a different purpose. With trade-off
analyses the question may be "How does cost change with increasing in-stream flow? Is it linear?
Are there points at which the increasing investment in management practices (i.e., total cost)
results in less increase in in-stream flow than the first $X?" To answer these questions, follow the
same steps as for the sensitivity analysis. For the in-stream flow example, increase the minimum
in-stream flow requirement with each run and record the results. Then examine the effect of this
increase on the combination of management practices that are suggested and the total costs and
revenues. A trade-off curve may be created, as in Section 3.2.3, by plotting total cost versus
percent of in-stream flow requirement to create a visual understanding of the trade-off and results.
30 http://www.epa.gov/osa/crem/training/module8.htm
30
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Case Study Examples
3. Case Study Examples
3.1 Upper Ipswich River Basin
The Ipswich River Basin (IRB) in Massachusetts is used as a case study for the application of the
model. The upper IRB is the watershed of the South Middleton Gaging Station of the United States
Geological Survey (USGS) on the Ipswich River and experiences low and no flow events during
summer months (Exhibit 3). The model is applied to the upper IRB to evaluate a broad range of
management options for meeting these objectives. A detailed modeling study of the IRB watershed
system was conducted by Zarriello and Ries (2000)31 of the USGS. That study compiled extensive
information and data on the basin which were used here. Relevant background information is
summarized below and the reader is referred to the 2000 study for a detailed watershed description.
Exhibit 3. Map of the Upper Ipswich River Basin.
METHUEN
Ipswich River 835111
• Miles
I«
Reach and Model ID
Surface-Water Withdrawal
Ground-Water Withdrawal
Open Water
Reach
Suboasin Boundary
Town Boundary
The upper IRB covers approximately 44 square miles (-Hydrologic Unit Code (HUC)-12 sub-
watershed) out of the total IRB area of approximately 150 square miles (-HUC-10 watershed). Of
31
Zarriello, P. J. and Ries III, K. G. (2000). A Precipitation-Runoff Model for Analysis of the Effects of Water Withdrawals
on Streamflow, Ipswich River Basin, Massachusetts. United States Geological Survey Water-Resources Investigation
Report 00^029.
31
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WMOST v1 and
this land area, 77% is developed. It comprises 14 towns but only four of these towns, Reading, North
Reading, Wilmington and Lynnfield, utilize the upper IRB for their water supply. The town of Lynn
is not located in the upper IRB but obtains 16% of its water supply from it (Zarriello and Ries 2000).
Exhibit 4 below lists the percent of each town's area within the upper IRB, percent of water supply
obtained from the IRB and resources for water and wastewater withdrawal and discharge.
Exhibit 4. Upper IRB Water Supply and Wastewater Services
Town
Lynn
Lynnfield
North Reading
Reading
Wilmington
Area in upper
IRB
0%
32%
100%
48%
83%
Supply from
upper IRB
16%
100%
100%
100%
100%
Water Source
Sw
Gw
(April to Nov-Sw)
Gw
(summer-import
<1.5MGD)
Gw
Gw
Wastewater Discharge
Sewer
(discharges out of
basin)
Septic
Septic
Sewer
(discharges out of
basin)
84% Septic
(16% discharges
out of basin)
Groundwater is almost exclusively the source of water supply except for Lynn which also lies outside
of the basin. The majority of the wastewater is discharged outside of the basin. At first, it may appear
that the majority of the wastewater is recharged via septic systems; however, only North Reading is
entirely within the basin boundary. Therefore, even septic systems are discharging some wastewater
to other basins and are neither recharging the IRB nor augmenting the flow of the Ipswich River.
Extensive groundwater withdrawals, the export of wastewater, and increased human demand during
low precipitation and high evapotranspiration months have been recognized as the most significant
contributors to the low and no flow events in the late summer in the basin (see Exhibit 5, Zarriello and
Ries 2000). Exhibit 5 shows in bold the three most critical months in 1999 when the lowest percent of
target flows were met and human demand were also the highest all year.
32
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Case Study Examples
Exhibit 5. Hydrologic Conditions in 1999
Date
Janurary
February
March
April
May
June
July
August
September
October
November
December
Target Flow
(ftj/s)
44
44
111
111
66
22
22
22
22
22
44
44
Streamflow
(ftj/s)
106.2
135.0
128.9
49.1
30.6
4.7
0.9
0.2
19.1
32.7
46.1
48.3
(as % of Target)
240%
305%
116%
44%
46%
22%
4%
1%
88%
151%
104%
109%
Precipitation
(in/month)
6.9
4.5
4.0
0.9
3.3
0.1
4.7
1.5
9.3
4.9
2.4
2.3
Human Demand
(ftj/s)
8.4
8.2
8.1
8.9
10.3
11.1
11.6
10.9
10.3
9.0
8.3
9.8
Note: Bold rows highlight the most critical months in 1999 when the lowest percent of target flow were met and human
demand were highest (Data from Zarriello, 200232 and Zarriello and Ries, 2000)
Optimization Scenario
WMOST was configured for a monthly time step for one year of modeling. We compiled data from
the USGS model as well as local sources as documented in Zoltay (2007). The data were for the year
1999 because it was the latest of the years for which pumping data were based on measured data in
the USGS model. The following management practices were specified as available for meeting U.S.
Fish and Wildlife in-stream flow targets and 1999 human water demand:
• Increasing or building new capacity for surface water pumping, groundwater pumping, water
treatment plant, wastewater treatment plant, water reuse facility, aquifer storage and recharge
facility, and nonpotable distribution system,
• Repairing leaks in the potable water distribution system and infiltration and inflow in the
wastewater collection system,
• Demand management via changes in pricing of water services,
• Bioretention basin for all FIRUs except forest, and
• Land conservation of forest HRU.
Interbasin transfers were excluded for the example scenario documented in this User Guide.
Results
Exhibit 6 summarizes the management options recommended by the model, along with the sub-costs
and total cost. The solution includes wastewater treatment capacity because wastewater services were
32
Zarriello, P. J. (2002). Simulation of Reservoir Storage and Firm Yields of Three Surface-Water Supplies, Ipswich River
Basin, Massachusetts. United States Geological Survey Water-Resources Investigation Report 02-4278.
33
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WMOST v1 User Manual and Case Study Examples
previously outsourced. In addition, the model "used" additional surface water pumping and aquifer
storage and recharge to shift the timing of surface and groundwater withdrawals and the recharge to
the aquifer which, after a delay, discharges as baseflow to the stream. In addition, reduction in
demand was implemented by increasing the consumer's price for water and eliminating leakage from
the distribution system. Finally, wastewater treatment costs and the loss of groundwater were
minimized by reducing groundwater infiltration into the sewer collection system.
Exhibit 6. Results for Meeting Minimum In-Stream Flow and Human Demand
Total Annual Cost
Water Revenue
Wastewater Revenue
$31.7
$13.1
$3.4
million
million
million
MANAGEMENT PRACTICES
UNITS
Number
of Units
Total Annual Sub-
Costs (incl. O&M)
Consumer Rate Change %
Additional SW Pumping Capacity
Additional GW Pumping Capacity
Additional Surface Water Storage
Additional WTP Capacity
Potable Distribution System Repair
Additional WWTP Capacity
Infiltration Repair
Additional ASR Capacity
MGD
MGD
MGD
MGD
% of Leaks
MGD
% of Infiltration
MGD
50
165
0
0
0
100
57
100
281
$3,260
$1,925,580
$210,649
$1,064,000
$13,850,100
$70,423
$9,392,270
$154,777
$4,997,340
34
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Case Study Examples
Compared to measured flows for a monthly model, to in-stream flows appear reasonable for both
magnitude and behavior or pattern.
Measured and Modeled Flows
200
180
160
Measured Flow
In-stream flow
Baseflow
Comparing the modeled in-stream flow to the specified target flows (i.e., minimum in-stream flow), it
is clear where the target 'forced' the model to implement management options to increase in-stream
flow (i.e., where the modeled in-stream flow is adjacent to the target).
35
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WMOST v1 User Manual and Case Study Examples
Target and Modeled Flows
42
u
O
200
180
160
140
120
100
Minimum in-stream
flow target
In-stream flow
36
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Case Study Examples
3.2
Danvers and Middleton, Massachusetts
The towns of Danvers and Middleton, Massachusetts (MA) were selected as a case study because they are
a pilot project for the Massachusetts Sustainable Water Management Initiative (SWMI)33 and because
they are located in the Ipswich River Basin (1KB) which experiences low and no flow events in the late
summer. The Ipswich River is the primary source of water for these towns. The site-specific data used in
this case study are from the U.S. Geological Survey (USGS) Hydrological Simulation Program-Fortran
(HSPF) simulation model, SWMI Framework, state databases and websites, and the towns' websites.
Please see Appendix A for details on input data values, sources/references and assumptions. We have
excluded some detail for readability and to keep focus on effects of scenario specifications on changes in
management practices and costs.
Please note that we were unable to coordinate with Danvers Water Division to corroborate data,
assumptions and interpretation of the results. In addition, the SWMI Framework does not specify
quantitative, minimum in-stream flow criteria for the basin in which Danvers and Middleton are
located. In order to run the model, we used the first basin category in the SWMI Framework with
quantitative criteria (i.e., least stringent of the quantitative criteria) to allow a hypothetical case
study and to be analyzed to demonstrate the application of WMOST for municipalities rather than
an entire watershed.
The Ipswich River Basin is 155 square miles, approximately a HUC-10 watershed. The town of
Middleton is entirely within the IRB while only 28% of Danvers drains to the Ipswich River (Exhibit 7).
The populations of Danvers and Middleton were 26,493 and 8,987 respectively, in 2010.
Exhibit 7. Danvers and Middleton, MA in the IRB
Town Boundaries
^) lps»ich River Watershed
http://www.mass.gov/eea/air-water-climate-change/preserving-water-resources/sustainable-water-management/
37
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WMOST v1 User Manual and Case Study Examples
Danvers maintains the sole water treatment plant and manages the distribution of water to Danvers and
Middleton. Middleton purchases all of its water from Danvers. Three surface water sources and two
groundwater wells serve as the source of water supply. Middleton Pond serves as the primary supply and
is supplemented with water from Emerson Brook Reservoir in Middleton, and Swan Pond in North
Reading during months of high demand.
In Danvers, wastewater is 99% sewered and exported to the South Essex Sewer District which discharges
outside of the IRB. Middleton's wastewater primarily discharges to septic systems except for three
properties.
Total water demand for Danvers and Middleton system (DM) has decreased since the 1990s due to
demand and other management efforts. However, DM expects to need 0.27 MGD in their new withdrawal
permit beyond the SWMI baseline withdrawals. SWMI baseline withdrawals for DM pilot study in the
SWMI Phase I Report are calculated as 2005 demand plus a growth factor of 8%. Withdrawals beyond
this amount require various levels of minimization of withdrawals and/or mitigation of withdrawal
impacts. Depending on the basin, in-stream flow criteria may apply. While Danvers is in a basin that does
not have quantitative flow criteria, we used the first category of basins with flow criteria in order to run
the model. Therefore, with a need for additional water for human demand and specifying quantitative in-
stream flow targets, we expected that the management solution would require new management practices
and, therefore, provide an illustrative example of the application of WMOST.
3.2.1 Model Setup
Part of the challenge in jointly modeling human and natural systems is that they often do not overlap. DM
is part of 18 subbasins of the IRB, as illustrated in Exhibit 3. The USGS developed a detailed HSPF
model of the IRB (Zarriello and Ries, 2000 and Zarriello, 2002) and which we used to obtain the data
necessary to model the DM subbasins. These data include the area of hydrologic response units (HRUs)34
within subbasins, HRU runoff and recharges rates, pumping rates, groundwater storage volumes and other
(see Appendix A). As shown in Exhibit 8 below, DM is only part of many subbasins. We modeled all
subbasins that overlap with DM for the hydrology but limited management options such as stormwater
practices to land areas within DM boundaries. All but two of these subbasins drain to consecutive reaches
of the Ipswich River with a pour point in reach 37. Subbasins 45 and 46 drain further downstream with a
pour point in reach 46 which drains to the main stem of the Ipswich River at reach 47. Therefore, we
aggregated outflow from reach 37 and 46 to derive a synthetic time series to use as 'measured flow' and
compare against WMOST modeled flow.
34 HRUs are areas of similar hydrology due to similar characteristics such as land use, soil and/or slope.
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Case Study Examples
Exhibit 8. Subbasins and Reaches of the IRB and Danvers and Middleton Town
Boundaries
15 Reach ID
HSPF Reaches
^] HSPF Basins Included in Mode!
HSPF Basins Not Included in Model
Town Boundaries
Ipswich River Watershed
In the IRB HSPF model HRUs are defined as a combination of land use and surficial geology with a total
of 11 HRUs in the DM subbasins. It is important to note that in the HSPF model, wetlands were not
simulated as land use but rather as stream reaches that were "placed" between the runoff from the HRUs
and the actual stream reach. Because wetlands change in area over which they have standing water, the
hydrology of wetlands changes significantly over the simulation period. For example, during the spring
and early summer, there may be significant evapotranspiration from wetlands. As they become more dry
and shrink in area, the amount of evapotranspiration decreases. This change in area and hydrology was
simulated using reaches that could be programmed to change area based on depth of water and geometry
of the channel. Because wetlands were not modeled as HRUs, there are no runoff and recharge rates
available for them. As a result, we were not able to include wetlands in the WMOST model at this time
and would require consultation with USGS on the most appropriate way to translate their modeling of
wetlands into the WMOST modeling structure and/or develop new functionality in WMOST.
3.2.2 Simulation
The first modeling step was to determine the accuracy of using data from the IRB HSPF model in
WMOST. Therefore, we used the hydrology and pumping data from HSPF and compared WMOST
modeled in-stream flow with the HSPF synthetic gage flow. Comparing with the synthetic gage flow was
necessary due to subbasin with DM that did not drain to consecutive stream reaches. The time period of
simulation was limited to the available surface water and groundwater pumping data in the HSPF model
which covered the years from 1989 to 1993. The simulation run used the following data:
• Land areas, runoff rates and recharge rates for 11 HRUs for 1990
• Surface water:
39
-------
WMOST v1
• External inflow to the study area calculated as sum of inflow from upstream subbasins
• Reservoir/Surface water storage: three ponds with usable storage
• Groundwater minimum, maximum and initial storage as well as recession coefficient
• Surface water and groundwater pumping data from 1989 to 1993
• Human demand:
o Disaggregated HSPF pumping data based on MA Department of Environmental
Protection (DEP) Annual Statistical Report (ASR) data into five user types
o Consumptive use values for each user were based on literature data
• Wastewater:
o Assumed all of Danvers is sewered and exported to South Essex Sewer District (i.e.,
interbasin transfer)
o Assume all of Middleton is septic and since all of the town area is within the IRB, all
septic discharge was assumed to recharge groundwater
• Exclusion of all management options
• No in-stream flow targets
Although there are options to exclude the use of new management practices, currently there is no
capability to prevent the model from optimizing the use of existing infrastructure. For example, DM has
both surface water and groundwater sources and the model may select a different timing and amount of
withdrawals from each source than the HSPF model simulated. To ensure the same behavior in WMOST
as in the HSPF model, we input all human withdrawals and returns as private surface and groundwater
withdrawals and discharges under the surface water and groundwater input sheets as follows:
• Surface withdrawal: HSPF surface water withdrawals
• Groundwater withdrawal: HSPF groundwater withdrawals and loss of groundwater due to
infiltration to wastewater collection system
• Groundwater discharge: Unaccounted for water calculated as percentage of total pumping and
septic returns from Danvers adjusted for consumptive use
Using the above data in the specified configuration, WMOST reproduced HSPF daily in-stream flow over
the five years with a Nash-Sutcliffe Efficiency (NSE) of 0.93.35 This value is an overall assessment of
model fit for the entire time period (see Exhibit 9 below). In the exhibit, HSPF flows were used to
represent "measured" flows which are compared against WMOST modeled in-stream flows. WMOST
modeled summer low-flows higher than HSPF flows. Low flows are an important element for the DM
case study because of the low flow issues in the IRB. A potential source of difference is the
evapotranspiration from wetlands. As explained in the model setup, the IRB HSPF model did not model
wetlands as a land area and, therefore, could not be included in the WMOST model.
In future refinements of this case study,36 it would be beneficial to consult with USGS on the most
appropriate way to represent the effects of wetlands in WMOST and other factors that may be
contributing to higher than measured low-flows. For example, it may be necessary to have two
35 The NSE ranges from 0 to 1. A value of 0 indicates that the model estimates values only as well as the average of the measured
data. A value of 1 indicates a perfect match to the measured data.
36 We provide recommendations throughout the case study but all recommendations are summarized at the end of the case study
section.
40
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Case Study Examples
groundwater storage components in the model - one to represent interflow which discharges more quickly
in response to recharge from storm events and another to represent active groundwater flow which
discharges at a slower and steadier rate. Alternatively, or in addition, it may be necessary to re-calibrate
the groundwater recession coefficient from the HSPF value to a value more representative for the lumped
spatial characteristics of WMOST. However, with respect to this case study, the low flows modeled are
lower than the quantitative, minimum in-stream flow targets. Therefore, we increased the minimum flow
targets by the percent difference between HSPF and WMOST flows. We were able to proceed with
optimization runs given that the model will need to select management practices that will provide
additional in-stream flow. As such the case study will provide insight into which management practices
are most cost-effective for increasing in-stream flow while meeting anticipated increase in demand.
Exhibit 9. Comparison of In-Stream Flows
600
Measured Flow I
In-stream now
Baseflow
1/1/1990
1/1/1991
1/1/1992
1/1/1993
Note: In some cases baseflow is higher than modeled in-stream flow. In-stream flow receives baseflow but also
has withdrawals; therefore, final flow in the stream may be lower than baseflow.
3.2.3 Optimization
The optimization was run to simultaneously meet two management goals at least cost: 1) projected
increase in human demand for DM based on baseline SWMI demand plus additionally requested
withdrawals by DM37 and 2) quantitative, minimum in-stream flow targets. We assumed a 20-year
planning period based on water withdrawal permit lifetimes and projected build-out land use based on
multiple data sources (see Appendix A for input data sources and values).
The following management practices were available for meeting the goals:
1. Meeting human demand by:
37
Note that the projected demand of 3.72 MOD is lower than the 1993 pumping of 4.56 MOD in the HSPF model.
41
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WMOST v1
a. Increasing withdrawals from surface and/or ground sources,
b. Purchasing interbasin transfer of water from the Massachusetts Water Resources
Authority (MWRA),
c. Reducing demand via increased pricing of water services, and
d. Reducing demand by providing rebates for water efficient appliances.
2. Meeting minimum in-stream flow criteria by:
a. Changing the rate and timing of pumping from surface and ground sources to alleviate
summer low flows,
b. Reducing withdrawals by:
i. Meeting human demand using options Ib through Id,
ii. Constructing a water reuse facility and nonpotable distribution system to reuse
water,
c. Increasing recharge to groundwater and, therefore, potentially increasing late summer
baseflow38 by:
i. Implementing infiltration-based stormwater management practices by allocating
urban HRU areas to one of six "managed" HRU sets each representing a different
stormwater management practice (i.e., bioretention basins, infiltration basins, or
horizontal wetlands sized to manage a 0.6 inch storm event; bioretention basins,
infiltration basins, or horizontal wetlands sized to manage a 2 inch storm event),
ii. Constructing an aquifer storage and recharge (ASR) facility to recharge
groundwater during flows above the in-stream flow criteria or from
reservoirs/surface water storage,
iii. Conserving forest or undeveloped open land,
d. Increasing surface storage capacity (e.g., size of storage tank, reservoir, pond),
e. Constructing a wastewater treatment plant and discharging to the Ipswich River rather
than exporting out of the basin, and
f. Reducing the infiltration and inflow (I/I) of groundwater into the sewer collection system.
Currently, WMOST is configured such that III into the sewer system flows to wastewater treatment plant.
In DM, all sewered wastewater is exported via interbasin transfer. Therefore, specifying an III rate would
create flow to a wastewater treatment plant rather than to interbasin transfer. In some of the scenarios
(Scenario 3 and 4), constructing a wastewater treatment plant is selected. In these scenarios, the III rate is
specified and its repair is available as a management practice. The modeling capability to specify III for
interbasin transfer is noted as a desired enhancement in Section 3.2.4 where we summarize future
recommendations for case study input data and model capabilities.
The timing and amount of recharge reaching a stream as baseflow depends on site specific parameters such as whether the
groundwater beneath the recharge area flows to the stream, the distance between recharge area and stream, and whether
there are any withdrawal wells between the stream and recharge area.
42
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Case Study Examples
Scenario 1: Base
For the first optimization scenario, we set all of the above management practices to be available to meet
management goals of projected demand and minimum in-stream flow targets. Exhibit 10 shows the non-
zero values from the results table.
While the objective of this case study is to minimize costs to meet management goals, it is interesting to
note that the total annual cost is lower than the water and wastewater revenue. The O&M costs for water
and wastewater were derived from online town budgets for the water and wastewater departments. The
total cost shown by the model approximately matches the sum of costs specified in the budgets
(approximately $5 million for water and $5 million for wastewater for both towns). However, these costs
may not include all costs incurred by the towns. For example, the comprehensive costs of providing water
services may include operation of source pumps, treatment, operation of the distribution system, capital
improvement, source protection, and administrative costs such as billing customers. We could not
determine additional costs the towns may incur that are not presented in the water department budgets.
Therefore, future refinement of this case study would require collaboration with the towns to understand
their comprehensive costs.
With respect to minimizing costs to meet human and in-stream flow demand, the model selected to:
• Implement pricing change to the maximum extent allowed (20% increase over the 20-year
planning period),
• Provide rebates for water efficient appliances to reduce demand at the maximum available 0.6
MGD possible, and
• Repair leakage in the potable distribution system to the maximum extent possible (fixing 99% of
the leaks was set as practical limit).
The water treatment plant capacity is sufficient; therefore, no additional capacity is necessary. The only
costs for the water treatment plant are those associated with annual operations. For wastewater, interbasin
transfer continues to be the sole service provider.
Exhibit 10. Base Scenario Results
Total Annual Cost
Water Revenue
Wastewater Revenue
$13.4
$10.2
$10.3
million
million
million
MANAGEMENT PRACTICES
UNITS
Number of
Units
Total Annual Sub-
Costs (incl. O&M)
Consumer Rate Change %
Direct Demand Reduction
Additional WTP Capacity
Potable Distribution System Repair
Additional IBT - Wastewater
MGD
MGD
% of Leaks
MGD
20
0.60
0.00
99
0.00
$3,846
$255,701
$6,721,130
$138,179
$6,271,870
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These results suggest that the more cost effective management practices are demand reduction via pricing
changes, direct demand management through providing rebates, distribution system repair, and continuing
with local water withdrawal and interbasin transfer of wastewater.
Implementation of these selected management practices increases the modeled in-stream flows as shown
in Exhibit 11, below. The modeled flows are greater than the specified streamflow criteria for all days in
the five-year modeling period as shown in Exhibit 12.
Exhibit 11. Base Scenario - Modeled and Measured In-Stream Flows
1,200
1,000
800
Measured Flow
In-stream flow
Baseflow
o
600
400
200
1/1/1990
1/1/1991
1/1/1992
1/1/1993
Note: Baseflow may be higher than modeled in-stream flow. In-stream flow receives baseflow but
also has withdrawals; therefore, final flow in the stream may be lower than baseflow.
Exhibit 12. Base Scenario - Modeled and Target In-Stream Flows
1,200
1,000
800
Minimum in-stream flow target
In-stream flow
Baseflow
42
u
1
600
400
200
1/1/1990
1/1/1991
1/1/1992
1/1/1993
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Case Study Examples
Scenario 2: Drought Resistant Landscaping and Reduced Summer Water Use
In-stream flow criteria are primarily exceeded in the late summer after a season of reduced precipitation,
increased evapotranspiration and increased human use (see Exhibit 5 in Section 3.1). A significant portion
of human use during the growing season (approximately May to September) is attributable to outdoor
watering. The efficiency of outdoor watering may be increased via moisture sensors and installation of
low water need/drought resistant landscaping. In addition, streamflow-triggered watering limits or bans
can reduce outdoor watering. Although the towns already have efforts underway to reduce outdoor
watering, we wanted to examine the effect of investing in additional practices as mentioned above. In this
scenario, we calculated a reduced summer outdoor water use as follows:
1. Calculate the average daily demand for the summer months (May through September) when
outdoor watering is expected and for the winter months (December through February) when
outdoor watering is not expected,
2. Determine the difference between the two daily rates and assume it represents outdoor water use,
3. Take 50% of the difference, thereby assuming that outdoor watering use could be reduced by 50%,
4. Subtract this amount from daily summer demand.
We also calculated new consumptive use percentages assuming that all reduction in demand is 100
percent consumptive.
Rerunning the model with these specifications reduced the total annual management cost, as may be
expected. The same management practices were selected as in the Base Scenario but with less demand
less water was provided and total cost decreased. It is important to note that both water and wastewater
revenue decreased. Most towns charge wastewater services based on metered water flow as is the case in
DM and in the model. While outdoor watering does not discharge wastewater, most towns' wastewater
services may be dependent on the total annual revenue according to current practices of charging
customers. Therefore, water conservation programs must prepare both the water and wastewater
departments for reduced revenues and potential need for rate increases that reflect the cost of services
provided and received flow, respectively. Since many towns are making allowance for separate outdoor
water meters and/or adjustment of summer wastewater charges based on winter water flow rates and
water conservation is a cost effective management practice as also shown in the Base Scenario, issues of
sustainable water and wastewater rates may be important to address.
Exhibit 13. Reduced Summer Water Use Scenario Results
Total Cost
Water Revenue
Wastewater Revenue
$12.8
$9.5
$9.6
million
million
million
MANAGEMENT PRACTICES
UNITS
Number of
Units
Total Annual Sub-
Costs (incl. O&M)
Consumer Rate Change %
Direct Demand Reduction
Additional WTP Capacity
Potable Distribution System Repair
Additional IBT - Wastewater
MGD
MGD
% of Leaks
MGD
20
0.60
0.00
99
0.00
$3,846
$255,701
$6,239,750
$138,179
$6,198,780
45
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WMOST v1 User Manual and Case Study Examples
For model enhancements, we recommend adding a management practice that reduces summer demand
based on a user specified streamflow threshold. This modeling capability would represent programs some
towns implement in the summer to limit outdoor watering during low flows. In addition, adding a direct
demand management practice that allows for reductions in specific months would also provide additional
flexibility for modeling outdoor water use management practices.
Scenario 3: Trade-off Curve-ln-Stream Flow and Costs
To evaluate trade-offs between in-stream flows and costs, we ran the case study five times with the base
scenario while increasing the in-stream flow criteria each time. We chose to increase the base criteria by
25, 50, 75 and 100 percent (i.e., set the minimum in-stream flows to 125%, 150%, 175%, and 200% of
base values). These percent increases translate to the flow criteria shown in Exhibit 14.
This series of runs provides insight into the: 1) trade-off between total cost and increasing in-stream flows
beyond the minimum criteria, 2) the relative cost effectiveness of practices that were not selected in
previous scenarios, and 3) additional information about potential management practices that may be
necessary to meet minimum in-stream flow once the model is better able to reproduce low-flows. The
results of these runs are shown below in Exhibit 15 and the trade-off curve between total cost and in-
stream flow is shown in Exhibit 16.
Exhibit 14. In-Stream Flow Criteria
January
February
March
April
May
June
July
August
September
October
November
December
In-Stream Flow (cfs)
Base
(100%)
16.56
19.10
17.28
19.46
15.98
18.51
18.46
18.76
18.85
17.52
17.52
17.09
125%
20.69
23.88
21.59
24.33
19.98
23.13
23.07
23.44
23.56
21.89
21.89
21.36
150%
24.83
28.65
25.91
29.19
23.97
27.76
27.68
28.13
28.28
26.27
26.27
25.63
175%
28.97
33.43
30.23
34.06
27.97
32.38
32.30
32.82
32.99
30.65
30.65
29.90
200%
33.11
38.20
34.55
38.92
31.96
37.01
36.91
37.51
37.70
35.03
35.03
34.17
Average
HSPFFlow
(1989-1993)
59.95
80.32
90.23
132.82
66.01
42.06
9.41
19.92
14.85
37.37
54.15
64.77
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Case Study Examples
Exhibit 15.
Results for Increasing In-Stream Flow Criteria
MANAGEMENT
PRACTICES
Consumer Rate
Change
Direct Demand
Reduction
Additional WTP
Capacity
Potable Distribution
System Repair
Additional IBT -
Wastewater
Infiltration basin,
0.6"
Additional WWTP
Capacity
Additional ASR
Capacity
Additional WRF
Capacity
Total Cost
Water Revenue
Wastewater Revenue
UNITS
%
MGD
MGD
%of
Leaks
MGD
Acres
MGD
MGD
MGD
millions
millions
millions
In-stream Flow Criteria
125%
Number
of Units
20
0.60
0.00
99
0.00
Total Annual
Sub-Costs
(incl. O&M)
$3,846
$255,701
$6,721,130
$138,179
$6,271,870
$13.4
$10.2
$10.3
150%
Number
of Units
20
0.60
0.00
99
0.00
1,255
0.75
0.71
0.06
Total Annual
Sub-Costs
(incl. O&M)
$3,846
$255,701
$6,721,130
$138,179
$6,255,920
$570,206
$706,592
$534,736
$44,680
$15.2
$10.2
$10.3
175%
Number
of Units
20
0.60
0.00
99
0.00
1,255
0.75
5.04
0.01
Total Annual
Sub-Costs
(incl. O&M)
$3,846
$255,701
$6,721,130
$138,179
$6,259,650
$570,206
$701,921
$3,815,700
$8,871
$18.5
$10.2
$10.3
200%
Number
of Units
20
0.60
0.00
99
0.00
1,255
0.75
9.49
0.20
Total Annual
Sub-Costs
(incl. O&M)
$3,846
$255,701
$6,721,130
$138,179
$6,208,070
$570,206
$766,399
$7,853,070
$140,575
$22.7
$10.2
$10.3
47
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The 25 percent increase in in-stream flow criteria produced the same result as the base scenario. This
result suggests that the base scenario was not entirely limited by in-stream flow and flexibility remained
in the system to meet a higher in-stream flow with the same set of management practices..
Achieving a 50 percent increase in minimum in-stream flows, however, requires, additional management
practices, including:
• stormwater management using infiltration basins sized for 0.6-inch storm event on commercial
land use with sand and gravel surficial geology,
• local wastewater treatment plant,
• water reuse facility (WRF) to supply the ASR facility (see below) with additionally treated
wastewater from the local wastewater treatment plant, and
• aquifer storage and recharge (ASR) facility that utilizes water from the surface water, reservoir
and WRF.
Exhibit 16. Trade-off Curve Between Increasing In-stream Flow and Total Cost
Percent of Base Scenario's Minimum In-Stream Flow Criteria
100%
125%
150%
175%
200%
Interestingly, the wastewater treatment plant is constructed to a maximum capacity of 0.75 MGD
but used variably among the scenarios as reflected in the total cost which includes costs for
O&M for the plant. Interbasin transfer of wastewater is relatively less expensive than local
wastewater treatment similar to the interbasin transfer of water because of economies of scale for
the larger system from which these services are bought. Therefore, although the model selects to
build a wastewater treatment plant, it only uses it during critical times when additional discharge
is necessary to meet in-stream flow. This suggests that not only is there a need to reduce demand
and withdrawals but also a need to increase discharge and recharge in the basin and river.
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Case Study Examples
However, treatment plants must have a predictable flow, and therefore, this solution would not
be practical. As a result, we ran another scenario where interbasin transfer of wastewater was
excluded and in-stream flow criteria were set at 200% of the base scenario (see Scenario 5
below).
• In continuing to examine the results of increasing in-stream flow criteria, we also note that ASR
is selected at an increasing capacity. Such high recharge capacities may not be feasible within the
land area and aquifer storage of DM. Therefore, it would be necessary to determine the
feasibility of the maximum amount of ASR and limit this management option to the feasible
capacity.
• Finally, we note the use of infiltration basins for a 0.6-inch design storm on 1,255 acres of
commercial land on sand and gravel. Commercial land has the highest percent impervious cover
while sand and gravel had the highest infiltration rate. These characteristics likely resulted in this
HRU being the most cost effective for stormwater management. No other HRUs were selected
for stormwater management.
• Given that infiltration basins and ASR system both recharge groundwater, it is interesting to note
that both management practices were selected. It is likely that infiltration basins on commercial
land over sand and gravel are more cost effective than ASR but the same does not hold true for
other HRUs. With future refinements, if a feasibility limit is set for ASR, stormwater
management for other HRUs may become relatively more cost effective.
Scenario 4: Exclusion of Interbasin Transfer of Wastewater and Double In-Stream Flow Criteria
Both interbasin transfer of wastewater and local wastewater treatment were selected as management
options in the high in-stream flow criteria scenarios. To evaluate the sensitivity of the selected practices to
the availability of certain practices, we re-ran the scenario requiring double the base scenario in-stream
flow but excluding interbasin transfer of wastewater. As may be expected, total costs increased but
otherwise the selection of management decisions were the same with slight differences in the maximum
capacity of ASR and WRF. It is possible that a town may elect to construct a treatment plant for the
minimum expected need for meeting in-stream flow and continue with interbasin transfer for additional
wastewater needs. In such a case, an additional scenario could be run where interbasin transfer is limited
to the total need minus the 0.75 MOD of local wastewater capacity selected in earlier scenarios. With the
inclusion of a wastewater treatment plant as in Scenario 3, I/I could be specified and the model selected to
repair III to the maximum extent possible. This result suggests that repair of groundwater flow into sewer
collection system is less expensive than treating a larger volume of wastewater and/or helps retain
groundwater in the aquifer for baseflow and is cost effective for meeting in-stream flow criteria.
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WMOST v1 User Manual and Case Study Examples
Exhibit 17. Results for Scenario with Exclusion of Interbasin Transfer of Wastewater with
Double In-Stream Flow Criteria
Total Cost
Water Revenue
Wastewater Revenue
$28.2
$10.2
$10.3
million
million
million
MANAGEMENT PRACTICES
UNITS
Number of
Units
Total Annual Sub-
Costs (incl. O&M)
Consumer Rate Change %
Direct Demand Reduction
Additional WTP Capacity
Potable Distribution System Repair
Additional IBT - Wastewater
Additional WWTP Capacity
Infiltration Repair
Infiltration basin, 0.6"
Additional ASR Capacity
Additional WRF Capacity
MGD
MGD
% of Leaks
MGD
MGD
% of Leaks
Acres
MGD
MGD
20
0.60
0.00
99
NA
5.52
99
1,255
9.27
0.44
$3,846
$255,701
$6,721,130
$138,179
NA
$12,938,300
$38,337
$570,206
$7,231,130
$344,822
Scenario 5: Sensitivity of Solutions to the Capital Cost of Interbasin Transfer of Water
The purchase of MWRA water was not selected as a management practice in any of the previous
scenarios. The source of the capital cost for purchasing MWRA water cited the value as an order-of-
magnitude estimate. To determine the sensitivity of suggested management practices to the capital cost of
purchasing MWRA water, we ran multiple scenarios decreasing this capital cost. The purchase of MWRA
water was not selected until the capital cost was reduced to less than 25% of the initial estimate. Exhibit
18 below shows results for capital costs that are 20% of the initial estimate.
In varying this capital cost, MWRA water was always either selected at full availability of 0.27 MGD or
not at all. This suggests that once the capital cost is reduced enough to make the practice cost effective,
the O&M or purchase cost of incremental volumes of water is less than that of the local water treatment
plant. This is further confirmed by the fact that the solutions for the other management practices do not
change except for a decrease in the amount of water withdrawn and provided by the local water treatment
plant as reflected in the lower cost for the water treatment plant. Similar to wastewater treatment,
economies of scale result in lower O&M costs for MWRA than the smaller local water treatment plant
($3,803/MG for MWRA compared to $5,314/MG for town produced water).
Although these solutions suggest that MWRA water connection is not cost effective until the capital cost
is reduced by more than 75%, this conclusion is based on scenarios that include a potentially infeasible
quantity of ASR. Therefore, once the maximum feasible ASR quantity is determined and limited, this
sensitivity analysis for the capital cost of MWRA water may be repeated to determine the capital cost at
which the management practice may be cost effective. Finally, it may be possible to finance or amortize
the MWRA capital cost over a longer time period than the planning horizon of 20 years. A longer
amortization period would lead to a lower annual payment or cost.
50
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Case Study Examples
These sensitivity runs demonstrate the importance of accurate input data. In addition, if the uncertainty or
range of values for an input is known, it provides an approach to determine whether that management
practice and the overall solution will remain constant over that range of values.
Exhibit 18. Results for Reducing the Capital Cost of Interbasin Transfer of Water
Total Cost
Water Revenue
Wastewater Revenue
$22.6
$10.2
$10.3
million
million
million
MANAGEMENT PRACTICES
UNITS
Number of
Units
Total Annual Sub-
Costs (incl. O&M)
Consumer Rate Change %
Direct Demand Reduction
Additional WTP Capacity
Potable Distribution System Repair
Infiltration basin, 0.6"
Additional WWTP Capacity
Additional IBT - Potable
Additional IBT - Wastewater
Additional ASR Capacity
Additional WRF Capacity
MGD
MGD
% of Leaks
Acres
MGD
MGD
MGD
MGD
MGD
20
0.60
0.00
99
1,255
0.75
0.27
0.00
9.49
0.20
$3,846
$255,701
$6,197,090
$138,179
$570,206
$766,399
$502,869
$6,208,070
$7,853,070
$140,575
Conclusions
Over all scenario runs, WMOST suggests several of the same management practices for meeting human
demand and in-stream flow criteria. These management practices are likely to be most cost effective, and
include:
• Demand management through pricing changes,
• Direct demand reduction via rebates,
• Repair of leakage from the potable distribution system, and
• Repair of infiltration into the sewer collection system.
Several management practices - local wastewater treatment and discharge, stormwater management,
ASR, and WRF - were selected as in-stream flow criteria were increased. Some practices such as ASR
were selected at capacities that are likely not feasible. Therefore, further input data based on a feasibility
study39 and additional modeling capabilities are necessary to limit some options to remain within realistic
limits (e.g., maximum limit on addition ASR capacity).
39 ASR is practiced in the Western and Southeast U.S. However, we did not find any ASR wells nor feasibility studies for ASR in
the Northeast (http://water.usgs.gov/ogw/artificial recharge.html,
http: //water. epa. go v/tvpe/groundwater/uic/aquiferrecharge. cfm# inventory).
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The DM case study example shows that, by running various scenarios, it is possible to identify the most
promising and cost effective management options for meeting management goals, and to assess the extent
to which these options remain cost effective under different sets of assumptions. However, the case study
also illustrates the importance of the input data and understanding the system dynamics to appropriately
interpret results and to conduct additional scenario runs, as needed, to ensure that relationships between
costs and the effect of management practices are accurately determined.
3.2.4 Refinements for Input Data and WMOST Capabilities
Based on this case study, the following enhancements would be useful in future versions of WMOST and
refinements of the DM case study:
• Module to help calibrate simulation for a few, key parameters that may be least accessible such as
initial, maximum, and minimum groundwater storage and the groundwater recession coefficient.
• Module specifically formulated for simulation such that all decisions are excluded from
optimization. Currently the use cannot exclude the optimization of existing infrastructure
operations (e.g., the amount of surface water versus groundwater that is used to meet demand).
• More options for interbasin transfer. For example, I/I could not be represented when only
interbasin transfer was used for wastewater services. However, the collection system in a town
may still have I/I into pipes that connect to the service provider outside of the basin. Therefore, an
option to have I/I and its repair represented even when all wastewater is transferred out of basin
would make the model more flexible and able to accurately represent more systems.
• For revenue calculations, additional input data would be needed but would make the calculation
more accurate if the user had the ability to specify fixed- and flow-based rates per water user type
(e.g., different rates for commercial and residential).
• In-stream flow triggered reduction in demand to represent outdoor water limits or bans that may
be implemented based on in-stream flow. For example, specify the reduction in demand when in-
stream flow falls below a user-specified threshold.
• Direct demand management practice for which reduction in demand can be specified by month.
• Sensitivity module to determine the point at which different management practices may be
selected. This is especially important for costs. For example, a feature that would allow user-
selected or all costs to be varied by +/-10% to determine effects on the selected combination of
management practices.
• Maximum feasibility determination for ASR capacity for DM.
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Case Study Examples
4. Appendix A. Danvers Middleton Case Study Input Data
Description Value Used in Model Original Values Data Source
LAND USE
Numberof land use sets (HRUs)
Stormwater Management Sets
Case study area
Scenario land area
Minimum area foreach land use
Maximum area foreach land use
Capital cost to conserve land use
O&M cost to conserve land use
Stormwater Management
Capital installation cost
O&M cost
RUNOFF AND RECHARGE
Recharge rates foreach original or "baseline" land
use
Runoff rates foreach original or "baseline" land use
Recharge rates foreach "managed" land use
Runoff rates foreach "managed" land use
WATER DEMAND
Demand foreach user foreach day
Unaccounted-for-water (i.e., leakage from potable
water distribution system)
Percent consumptive use foreach water user for
each month
Nonpotable water
Maximum percent demand that can be met by
nonpotable waterforeach user
Percent consumptive use for nonpotable water for
each userforeach month
11
6
23,810 acres
see model for individual
values
see model for individual
values
see model for individual
values
$187,408/acre
$1874.08/acre
see case study model for
individual costs
see case study model for
individual costs
in/day
in/day
in/day
in/day
see case study model for
individual values
6%
see case study model for
individual values
see case study model for
individual values
see case study model for
individual values
11
6
HSPF subbasins that overlap with DM
See User guide for LU calculations
See User guide for LU calculations
See User guide for LU calculations
Average of 2 forested lots: Mis #:
71204964, Mis #: 71156281
1% of capital costs
Cost per Acre for each BMP
Cost per Acre for each BMP
see case study model for individual
values
see case study model for individual
values
see case study model for individual
values
see case study model for individual
values
see case study model for individual
values
6%
see case study model for individual
values
see case study model for individual
values
see case study model for individual
values
HSPF
6BMPs: Bioretention, infiltration basin and horizontal wetland designed forthe
0.6" and 2.0" storm; Original HSPF runoff and recharge rates were modified based
on EPA Region 1 Stormwater DSS model forthese BMPs
HSPF subbasin shapefile
HSPF shape files, MassGIStown, protected openspace, zoning, 2005 land use
layers
HSPF shape files, MassGIStown, protected openspace, zoning, 2005 land use
layers
HSPF shape files, MassGIStown, protected openspace, zoning, 2005 land use
layers
http://www.verani.com/real-estate/Middleton/MA/land
BPJ
Charles RiverWatershed Association/Horsely-Witten Group
Charles RiverWatershed Association/Horsely-Witten Group
HSPF - interflow plus recharge
HSPF -runoff
6 BMPs: Bioretention, infiltration basin and horizontal wetland designed forthe
0.6" and 2.0" storm; Original HSPF runoff and recharge rates were modified based
on EPA Region 1 Stormwater DSS model forthese BMPs
6 BMPs: Bioretention, infiltration basin and horizontal wetland designed forthe
0.6" and 2.0" storm; Original HSPF runoff and recharge rates were modified based
on EPA Region 1 Stormwater DSS model forthese BMPs
Optimization: SWMI 2005 baseline +8% growth factor + additionally requested
withdrawal by Danvers (SWMI Phase 1 Report). Usertypes: Average over 2010-
2012 from DEP ASRs: 6% UAW, 58% Residential, 26% Commercial, <1% Agricultural,
<1% Industrial, 10% Municipal
MA DEP ASRs 2010-2012
Based on data from Amy Vickers (2002) Handbook of Water Use and Conservation
Based on data from Amy Vickers (2002) Handbook of Water Use and Conservation
Based on data from Amy Vickers (2002) Handbook of Water Use and Conservation
53
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WMOST v1 User Manual and Case Study Examples
Description Value Used in Model Original Values Data Source
Demand Management
Price elasticity for each user
Capital cost to implement price increase
O&M cost to administer price increase (e.g.,
resurvey for appropriate price etc.)
Maximum price change over planning horizon
Initial cost by providing rebates
O&M cost of providing rebates
Maximum demand reduction
SEPTIC
Percent septic use for each user
SURFACE WATER
Reservoir Storage
Initial reservoir volume
Minimum reservoir volume
Current maximum reservoir volume
Capital construction cost
O&M costs
Stream/low
Inflow from external surface water
In-stream flow standards
Maximum flow standard
Private withdrawals of surface water
Private discharge of surface water
see case study model for
individual values
$23,OOO
$2,OOO/yr
20%
$3,186,600
$0
0.6MGD
9.4%
533 MG
0
710 MG
$1,542,790/MG ($2013)
$15,428/MG ($2013)
cfs; See model for inidividual
values
cfs; See model for monthly
values
NA
0
0
see case study model for individual
values
$23,OOO
$2,OOO/yr
20%
Total cost for high-efficiency
appliances; Ideally, the usershould
determine the anticipated annual
rate of use of rebates by households
in order estimate annual cost rather
than total maximum use and one
initial cost.
None
Total reduction in daily demand
from high efficiency appliances
99% Danvers is sewered, ~2,155on-
site septics in Middleton (SWMI Phi)
* 2.68 ppl per HH - 64.3% of pop on
septics (total pop is 8987). Middleton
accounts for 14% of water. So 64% of
14% is 9.4% on septic.
75% of active volume
0
710 MG active volume
$1,542,790/MG ($2013)
1%
Sum of RIV_FLOW from Reaches: 16,
17, 23, 32
Seasonal streamflow criteria for FL3
applied to August median
unaffected flow adjusted for
difference between WMOST and
HSPF flows
NA
Not available
Not available
Based on Beecher 1994- reviewed over 1OO price elasticity of demand studies:
residential: -0.2to -0.4; industrial:-0.5to -0.8
(Town of Breckenridge ~ 24,OOO people served/day) Rogers, G. H. (2O04). "Water
Conservation Plan, Town of Breckenridge." Accessed
April 20, 2O05. http://www.townofbreckenridge.com/documents/page
/Water%20Efficiency%20Plan%202O04.pdf
(Town of Breckenridge ~ 24,OOO people served/day) Rogers, G. H. (2O04). "Water
Conservation Plan, Town of Breckenridge." Accessed
April 20, 2O05. http://www.townofbreckenridge.com/documents/page
/Water%20Efficiency%20Plan%202O04.pdf
BPJ based on existing tie red pricing structure and demand management practices
Total Households in 1990-9382+1240-10622
Rebates $10O/de vice-dish washer, washing machine, high efficiency toil et-
$300/household
$300x10622-3, 186,600
BPJ
Washers = 80OOgal/hh/yr
Dishwashers = 2150gal/hh/yr
Toilets- 1058gal/hh/yr
Total Households - 10622
MA DEP ASRs 20OO-2012, Personal communication with Derek Fullerton/Director
of Public Health/Middleton
BPJ
Since active volume specified in report, assume that volume is max and min is
zero (http://pubs.usgs.gov/sir/20O6/5044/pdf/SIR2O06- 5044.pdf
page 12)
see above
Avg of EPA 2O03 and Reading MA on finished water above ground storage
BPJ; did not see line item in town budgets so set at a minimum value
HSPFRIV FLOW parameter
SWMI Phase 1 Report
None known
None known
54
-------
Case Study Examples
Description Value Used in Model Original Values Data Source
GROUNDWATER
Groundwater recession coefficient
Initial groundwater volume
Minimum volume
Maximum volume
Flow from external groundwater
Private withdrawals of groundwater
Private discharge of groundwater
INTERBASIN TRANSFER
Purchase price for IBT potable water
Purchase price forlBTwastewater
Initial cost for new/additional IBT potable water
Initial cost for new/additional IBTwastewater
Daily limit for wastewater
INFRASTRUCTURE
Planning horizon
Interest rate
0.01
1134 MG
706 MG
2838 MG
0
0
0
$3,803/MG
$6,340/ MG
$29,500,000/MGD
0
6MGD
20 years
5%
1 minus area weighted average of
AGWRC for HRUs in study area
Sum AGWS across all HRUs for Day 1
of simulation (HSPF output in inches,
mult by blended areas IMPL & PERL
to get volume)
Sum AGWS across all HRUs (HSPF
output in inches, mult by blended
areas IMPL & PERL to get volume),
take min MGD over simulation
period and add 10%
Sum AGWS across all HRUs (HSPF
output in inches, mult by blended
areas IMPL & PERL to get volume),
take max MGD over simulation
period and add 10%
0
Not available
Not available
$3,032/MG+$771/MG
$5,930,789/935 MG
Waterdemand is 0.27 mgd (4.07-
3.72) 3.72 mgd is WMA authorized
withdrawal volume. 4.07is20-yr
demand from DCR
MWRA connection cost: $8 mil for
0.27 MGD inclusive of joining fee and
construction costs
Already exists
6 MGD
20 years
5%
HSPF
HSPF parameter AGWS
HSPF parameter AGWS
HSPF parameter AGWS
No uppersubbasins with groundwater draining to study area
None known
None known
MWRAwatercost (http://www.mwra. state. ma. us/finance/intro. htm): $3,032/MG
plus cost for operating distribution system and administrative functions $771
(based on Middleton water budget divided by MG since Middleton only buys from
Danvers and distributes)
Based on Danvers wastewater division annual budget divided by estimated 2012
MG wastewater flow
http://www.wickedlocal.com/weston/news/x8S8522107/At-MWRA-water-use-
drops-but-expenses-dont
$5mil/mgtojoin
About $250/lf to build water line (Smiles)
($5mil/mgd*.27mgd)+$250/lf*5miles*5280ft/mile=$7.95
$7.95 mil/0.27mgd=$29,500,000/MGD
Assume additional flow would not require capital contribution
Based on estimated existing use of SESD
SWMI permitting horizon
EPA Community Water System Survey 2000
55
-------
WMOST v1 User Manual and Case Study Examples
Description Value Used in Model Original Values Data Source
Water Treatment Plant
Customer's price for potable water
Gw pumping -Capital construction cost
Gw pumping -O&M costs
Gw pumping -Current max capacity
Gw pumping lifetime -remaining on existing
construction
Gw Pumping lifetime- new construction
Sw pumping -Capital construction cost
Sw pumping -O&M costs
Sw pumping -Current max capacity
Sw pumping lifetime -remaining on existing
construction
Sw Pumping lifetime- new construction
Wtp- Capital construction cost
Wtp -O&M costs
Wtp lifetime -remaining on existing construction
Wtp lifetime- new construction
Wtp-Current max capacity
Capital cost of survey & repair
O&M costs for continued leak repair
Maximum percent of leaks that can be fixed
$5.03/HCF
$747,285/MGD($2013)
$0/MG
1.74 MGD
33 years
35 years
$453,885/MGD ($2013)
$0/MG
10.42 MGD
33 years
35 years
$2, 022,884/ MGD
$5,314/MG
33 years
35 years
9.4 MGD
$774,368
$77437/yr
99%
Residential: $5.03/hcf(0- 20 hcf), 5.50
(20-24), 7.26 (over 24 hcf); Base fee
per quarter: $10.50/HCF -> base fee
was not included, unknown number
of connections
$747285/MGD ($2013)
0
Max daily over timeperiod +10% =
1.74 MGD
33 years
35 years
$453,885/MGD ($2013)
0
Max daily over timeperiod +10% =
10.42 MGD
33 years
35 years
$17.7 million in 2011$, CCI 2011 to
2013 = 1.0743
$5,754,928/ 1083 MG
Built in 1976, bid for renovations in
2011, 24 mo construction (33 years)
35 years
9.4 MGD
$774,368
10% of capital
99%
MA DEP RGPCD Ave: 56.2, Ave Danvers HH =2.42ppl, Ave HCF/HH/mo =5.45 HCF
(1st tier), Town of Danvers website:
http://www.danvers.govoff ice. com/index. asp?Type=B_BASIC&SEC=%7BC6DlF088
6DOB-470A-A159-5734F9D4C585%7D
EPA Water need survey 2003, CCI data to update costs
Based on town budgets, included in WTP O&M
MA DEP ASRs 2000-2012
Assume same as WTP, no other data source identified
Assume same as WTP, no other data source identified
EPA Water need survey 2003, CCI data to update costs
Based on town budgets, included in WTP O&M
MA DEP ASRs 2000-2012
Assume same as WTP, no other data source identified
Assume same as WTP, no other data source identified
CCI data, and: http://www.wickedlocal.com/danvers/news/xl852609581/Danvers
water-treatment-plant-receives-17-million-bidSaxzz2OsOZSAmf
Based on town budgets' water division annual budget divided by 2012 MG
demand
http://www.wickedlocal.com/danvers/news/xl852609581/Danvers-water-
treatment-plant-receives-17-million-bidSaxzz2OsOZSAmf
http://www.wickedlocal.com/danvers/news/xl852609581/Danvers-water-
treatment-plant-receives-17-million-bid#axzz2OsOZSAmf
MA DEP ASRs 2000-2012
Based on MWRA project in Lynnfield, MA scaled to miles of pipe in Danvers and
Middleton (0.62% of pipes need fixing, $145/ft (in$2004) detection and repair)
BPJ
BPJ
56
-------
Case Study Examples
Description Value Used in Model Original Values Data Source
Water reuse facility
Capital construction cost
O&M costs
Lifetime remaining on existing construction
Lifetime of new construction
Current maximum capacity
Nonpotable water distribution system
Consumer cost for nonpo table water
Capital construction cost for nonpotable
distribution system
O&M cost for nonpotable distribution system
Aquifer Storage and Recovery
Capital construction cost
O&M costs
Lifetime remaining on existing construction
Lifetime of new construction
Current maximum capacity
$10,402,467/MGD
$2,850/MG
Oyrs
35 years
OMGD
$3.02/HCF
$12,529,440/MGD
$1,716/MG
$10,807,824/MGD
$3,769/MG
Oyrs
35 years
OMGD
$6 million/ MGD ($1996)
10% of capital, convert to MG
No existing WRF
35 years
No existing WRF
60% of potable price
$80, 188,416 for all pipes; assume no
more than half of demand met by
nonpotable
5%
No existing ASR
35 years
No existing ASR
Asano 1998; since small towns assume plant size between 1-5 MGD; assume
upgrade from secondary to tertiary treatment that meets nonpotable reuse and
ASR standards
BPJ
BPJ
http://www.irwd.com/customer-care/understanding-your-bill/recycled-water-
rates.html
EPA 2003 average cost per foot of distribution main: $93.16 (2003$) = 135.60
($2013). SWMI Phase 1- 112 miles of pipe; Max Np use is ~6.4 MGD
Assume since new pipes, less O&M than usual 10%
EPA Water need survey 2003 for injection well costs and Asano 1998 for treatment
cost to meet gw recharge standards
EPA Water need survey 2003 for injection well costs and Asano 1998 for treatment
cost to meet gw recharge standards
BPJ
MEASURED FLOW
Measured flow
cfs; See model for inidividual
values
Sum of RIV_F LOW from Reaches: 37
and 46
HSPF RIV_FLOW parameter
57
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United States
Environmental Protection
Agency
Office of Research and Development
National Health and Environmental
Effects Research Laboratory
Atlantic Ecology Division
Narragansett, Rl 02882
Official Business
Penalty for Private Use
$300
Recycled/Recyclable
Printed with vegetable-based ink on paper that
contains a minimum of 50% post-consumer fiber
and is processed chlorine free.
iSORTED STANDAR
POSTAGE & FEES PAI[
EPA
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