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Environmental Modeling Community of Practice

Managing Watersheds with WMOST

Managing Watersheds with WMOST (Watershed Management Optimization Support Tool)

The Watershed Management Optimization Support Tool (WMOST) allows water-resource managers and planners to screen a wide range of practices for cost-effectiveness in achieving watershed or water utilities management goals, such as meeting projected water demand and minimum and maximum in-stream ecological flow targets.

Presented by Dr. Naomi Detenbeck

Naomi Detenbeck earned a Master’s and Ph.D. in ecology from the University of Minnesota-Minneapolis. Dr. Detenbeck currently works in EPA’s Office of Research and Development, Atlantic Ecology Division, overseeing projects to evaluate the effectiveness of green infrastructure stormwater BMPs at the small watershed scale, focusing on stream habitat and biological endpoints. She is also project lead for e-Estuary and oversees the development of WMOST.

Managing Watersheds with WMOST Webinar(55 pp, 19 MB, January 22, 2014, 267481)


Detenbeck, N. Managing Watersheds with WMOST (Watershed Management Optimization Support Tool). Presented at Safe and Sustainable Water Resources (SSWR) Webinar Series (#1), Narragansett, RI, January 22, 2014.


EPA’s Green Infrastructure research program and EPA Region 1 recently released a new public-domain software application, WMOST, which supports community applications of Integrated Water Resources Management (IWRM) principles. See WMOST User Manual and Theoretical Guide records. The application was created with a user-friendly Excel-based interface for data entry and presentation of results in tabular and graphical form. The Watershed Management Optimization Support Tool (WMOST) allows water resource managers and planners to screen a wide range of practices for cost-effectiveness in achieving watershed or water utilities management goals such as meeting projected water demand and minimum and maximum in-stream ecological flow targets. WMOST optimizes within a watershed system context, accounting for the direct and indirect cost and performance of each practice. WMOST can be used to (1) identify the most cost-effective mix of management practices to meet projected human demand and in-stream flow standards, (2) understand trade-offs between meeting management goals (e.g., human demand or in-stream flow) and total annual costs, (3) characterize the sensitivity of the solution to input data and parameters (e.g., effects of climate change and resulting changes in runoff and recharge rates on the mix of least-cost practices, the robustness of the recommended mix of practices to a range of cost assumptions). WMOST allows evaluation of over twenty potential management practices and goals related to water supply (demand management practices, surface and groundwater pumping, surface water storage, water treatment plant, potable distribution system leak repair), wastewater (septic systems, wastewater treatment plant, infiltration repair in wastewater collection system), nonpotable water reuse (wastewater reuse facility, nonpotable distribution system), aquifer storage and recharge, interbasin transfer of water and wastewater, land conservation and up to fifteen stormwater management practices including traditional, green infrastructure and LID practices, minimum human demand, and minimum and maximum in-stream flow targets. WMOST calculates the optimal solution based on user inputs of watershed characteristics, human water system characteristics, management practices, and management goals. WMOST was developed in collaboration with US EPA Region 1. The application was refined following input from a Technical Advisory Group composed of watershed modelers, water resource managers, and agency staff. The tool was tested through two case studies, one for the upper Ipswich River watershed in Massachusetts, and the second for the Danvers/Middleton, MA communities. The example paralleled the development of a case study for Massachusetts's Sustainable Water Management Initiative (SWMI) process. Results of the case studies were presented in a workshop with stakeholders at EPA Region 1’s Chelmsford Laboratory, which introduced the concepts of integrated water management, and solicited feedback from potential users on tool usefulness and desirability of features to be added in the future.


This is the first in a series of webinars for EPA ORD's Safe and Sustainable Water Resources (SSWR) Program. An overview of the Watershed Optimization Support Tool (WMOST) is presented. WMOST is part of a new generation of tools ORD is producing, like the Triple Value Model being created for Narragansett Bay, that enable stakeholders to simultaneously consider ecological, economic, and human benefits in developing sustainable solutions. It integrates existing tools into a decision support system that allows communities to determine costs and benefits of various stormwater management options, including current and projected future land-use, current and proposed stormwater best management practices (both green and gray), options for repairing leaks in the system, interbasin transfers of drinking water or wastewater with neighboring communities, aquifer storage and recharge systems, water conservation strategies, current and future water demand, etc. The system accounts for both capital and O&M costs for different management options. Communities can evaluate a range of options, examining for optimal solutions.



Record Details:

Completion Date: 01/27/2014
Record Last Revised: 01/27/2014
Record Created: 01/27/2014
Record Released: 01/27/2014
OMB Category: Other
Record ID:  267481




green infrastructure, watershed, decision support, integrated planning, integrated water resources management, ORD-007245