Science Inventory

Watershed Management Optimization Support Tool (WMOST) v1: User Manual and Case Study Examples


U.S. EPA. Watershed Management Optimization Support Tool (WMOST) v1: User Manual and Case Study Examples. U.S. EPA Office of Research and Development, Washington, DC, EPA/600/R-13/174, 2013.


The U.S. Environmental Protection Agency (US EPA) has endorsed the concept of IWRM, focusing on coordinated implementation of stormwater and wastewater management[1], and several states and river basin commissions have already started to implement IWRM[2] (including drinking water management as well). 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 protection6. 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 (Zoltay et al. 2010). 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 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. WMOST is implemented with a user-friendly interface in Excel for data input and output display, supported by VBA coding with linear optimization accomplished through linkage to LP-solver. Development of the WMOST tool was overseen by an EPA Planning Team. Priorities for update and refinement of the original model 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 are presented in the user guide. 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. [1]Nancy Stoner memo: [2] AWRA. 2012. Case Studies in Integrated Water Resources Management: From Local Stewardship to National Vision. American Water Resources Association Policy Committee, Middleburg, VA.


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).1 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).

Record Details:

Product Published Date:11/08/2013
Record Last Revised:12/30/2013
OMB Category:Other
Record ID: 262280