Logging in to CAST allows users to rapidly develop scenarios for reducing nitrogen, phosphorus and sediment with varying best management practices to streamline environmental planning. Costs are provided so users may select the most cost-effective practices to reduce pollutant loads.

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Frequently requested data and information associated with water quality monitoring and modeling.

Model Documentation

Find additional information about the Phase 6 model, its documentation and links to model review webinars and files.

Developing Plans

Get answers to your questions about how to use CAST to develop a plan.

Source Data

Download data tables including information on load sources and agencies, BMPs, animals, geographic references and delivery factors.

Calibration Inputs

Find graphs and maps of inputs to the Phase 6 Watershed Model Calibration for all versions.

BMPs, Models & Geography

View additional information on BMPs, CBP Partnership Models, Shapefiles and Geographical Information.

TMDL Tracking

Information on how to submit progress data via NEIEN and view implemenation data on meeting the Chesapeake Bay TMDL.


Resources to determine cost effectiveness of BMPs in units of dollars per pound reduced.

River Trends

Scientists calculate flow-adjusted trends in nitrogen, phosphorus and sediment levels to better determine whether pollution has changed over time.

Planning Goals

Download tables of local area planning goals for each state. These will help with planning for the Phase 3 Watershed Implementation Plans.