Model My Watershed: A Web-Based BMP Planning Web Application for Automated Modeling and Decision Support

Date / Time:
Wednesday, Sep 16 11:30am to 12:00pm
Track / Session:
Track: Data Management, GIS / GIS Tools, and Modeling / Session 6

High-performance watershed models and modeling tools are complex mathematical frameworks that can require significant data requirements to establish an understanding of site-specific water quality. With the proliferation of stormwater LID and a focused attention on assuring pollutant reductions from planned stormwater practices, established and trusted models and tools are required. Unfortunately, many of these tools require substantial training and/or expensive software to use, limiting their broad adoption.


We will discuss Model My Watershed, a powerful, free and easy-to-use web-based watershed analysis, modeling, and decision support tool that can be used to develop an understanding of water quality impacts of stormwater management scenarios. Model My Watershed is a high-performance, widely applied, award-winning conservation decision support web application that provides powerful watershed modeling tools while streamlining data collection requirements.  As this web applications and data systems work anywhere in the continental USA, Pennsylvania’s Department of Environmental Protection (PaDEP) has begun to recommend and utilize them to meet their MS4 and TMDL requirements for EPA and Chesapeake Bay.


Model My Watershed ( is designed for users to (1) automatically delineate a watershed anywhere in the continental United States based on the national elevation model; (2) analyze national land use, soil,  and other geospatial data for that watershed; (3) parameterize the Generalized Watershed Loading Function Enhanced (GWLF-E) model and simulate 30-years of daily water balance and nitrogen, phosphorus and sediment loads for each NHD+ catchment; and (4) compare how different conservation or development scenarios could modify runoff and water quality. This entire workflow can be completed in under 60 seconds from a web browser. Such high performance is enabled by Apache Spark and the GeoTrellis high-performance geospatial analysis engine ( deployed on Amazon Web Services (AWS) cloud cyberinfrastructure. Model My Watershed and its components are fully open-source (


We will describe how we developed this system to meet the needs of conservation organizations and municipalities. We will explain why Pennsylvania and other jurisdictions and organizations are adopting these systems to meet their needs, and funding enhancements to automate integrations with EPA’s National Environmental Information Exchange Network (NEIEN) to account for existing BMP implementation when simulating pollutant loads. We will also present our current efforts to integrate these technologies into a real-time water quality and flood forecasting system, which automatically harvests real-time data from CUAHSI Water Data Services (including EnviroDIY), the USGS/EPA Water Quality Portal, and the National Water Model to drive a water quality and runoff model for decision support purposes.


We will share our vision to further develop these systems to harness the self-interests of conservation organizations to voluntarily contribute BMP data to automate the tracking, modeling and reporting of cumulative and future benefits of all BMPs within regional watersheds. We believe that such an approach has great potential to assist planning and management of watershed conservation in California.

Primary Speaker:
Steve Skripnik, LimnoTech

Steve Skripnik, PE, is an environmental engineer with expertise in stormwater runoff and watershed management issues, surface water hydrology, low-impact development, and complex environmental data management and analysis. Steve’s project experience has included the development and application of a variety of watershed hydrology, storm and sanitary sewer collection system, and receiving water models, and working with clients to develop plans that are resilient to a changing environment. Steve has experience in a wide range of open-source and proprietary modeling tools and data management frameworks to support the development and review of TMDLs, permits, planning documents, infrastructure design, and planning projects. 

Supporting Speaker 1:
Anthony Aufdenkampe, LimnoTech

Dr. Anthony Aufdenkampe has over 20 years of experiencesynthesizing watershed data and models. He co-founded the Model My Watershed, Monitor My Watershed and EnviroDIY projects while at the Stroud Water Research Center, and he continues to lead technical development on these projects since joining LimnoTech in 2016. Dr. Aufdenkampe is a Senior Environmental Scientist at LimnoTech’s Oakdale, MN office.