The Virginia Assessment and Scenario Tool (VAST) allows users to rapidly develop scenarios with varying best management practices.

Output includes nitrogen, phosphorus, and sediment loads from all sectors and sources and the acres of each BMP for any area in the Chesapeake Bay Watershed. These loads are consistent with the Chesapeake Bay Program’s Watershed Model. VAST also provides inputs to the Chesapeake Bay Program computer models.

Users can compare among scenarios to select the practices that reduce the most pollution and target these practices to the highest impact areas. Scenarios can be used for TMDL Watershed Implementation Plans, Milestones, or for local planning purposes.