Occoquan Watershed Modeling Study

Case Study Under:  Environmental Solutions         Location:  Virginia
The Case Study

Occoquan Watershed Modeling Study

The Situation

The Occoquan reservoir serves as the water supply to over 1 million people in the Virginia suburbs of Washington, DC. Protecting this water source is a human health and economic development necessity for over a dozen local municipalities and water suppliers.

The Northern Virginia Regional Commission (NVRC), in association with the group of stakeholders, selected GKY to develop a modeling system that could be used to predict the impact of future land development on the region’s source water quality.

The Solution

GKY developed a linked watershed and reservoir water quality modeling system to provide a predictive model. We used systems proven in watersheds across the US: the Hydrologic Simulation Program – FORTRAN (HSPF) to model watershed hydrology and runoff water quality, and the 2D model CE-QUAL-W2 to simulate vertically-stratified hydrodynamics and water quality within the reservoir.

NVRC and its client municipalities now have an accurate, user-friendly tool to quantify the impact of proposed land development on the Occoquan reservoir.