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IWSS Hosts Seminar by USGS Watershed Modeler

The West Virginia University (WVU) Institute of Water Security and Science (IWSS) hosted U.S. Geological Survey (USGS) Watershed Modeler Gary Shenk for a September 7 seminar that provided information about efforts to revise the Chesapeake Bay Program’s Watershed Model. The revised model, known as the Phase 6 Watershed Model, will be used to guide management actions between 2018 and 2025 designed to achieve the nutrient and sediment total maximum daily loads (TMDLs) needed to meet restoration goals.

USGS Watershed Modeler Gary Shenk

According to Shenk, a cross-disciplinary modeling team of federal, academic, and contractor scientists at the Chesapeake Bay Program Office is revising the watershed model with extensive input from approximately a dozen stakeholder groups within the CBP Partnership. These groups have varied representation including federal, state, and local governments; academic institutions; trade organizations; and non-government organizations, all of which helped determine the three main themes for watershed model development that are applied in phase 6 including improving input data; utilizing multiple models and lines of evidence; and employing a simplified modeling approach.

“In all, hundreds of participants from dozens of organizations collectively have direct control over modeling approaches,” said Shenk. “This stakeholder-driven process of development will result in a model that is more accurate in representing new scientific findings, more accessible to users, and more accepted by the community.”

Shenk is located in the Environmental Protection Agency’s (EPA’s) Chesapeake Bay Program Office in Annapolis, MD, and focuses on the development of environmental models and the application of models and monitoring analysis to management questions. He leads a multi-disciplinary team responsible for the development and operations for the CBP Partnership’s watershed modeling effort. Over the past 20 years, he has overseen a substantial growth in watershed modeling complexity and scale, responding to the growth in the specificity of management questions. His work in Chesapeake modeling and monitoring informed a number of technical aspect of the Chesapeake Bay TMDL.


Gary Shenk is a watershed modeler with the USGS at the EPA’s Chesapeake Bay Program Office in Annapolis Maryland. In this position he focuses on the development of environmental models and the application of models and monitoring analysis to management questions. He leads a multi-disciplinary team responsible for the development and operations for the CBP Partnership’s watershed modeling effort. Over the past 2 decades in this position, he has overseen a substantial growth in watershed modeling complexity and scale, responding to the growth in the specificity of management questions. His work in Chesapeake modeling and monitoring informed a number of technical aspect of the Chesapeake Bay TMDL. As a participant in many of the ongoing CBP technical groups, Gary has the opportunity to forge collaborations with federal, state, academic, and other non-governmental organizations. Gary holds a B.A. in economics and an M.S. in Civil Engineering, both from the University of Virginia.

This seminar was partially supported by the National Science Foundation under Award No. OIA-1458952.