Map Tools


Files are available for download as GIS layers and KMZ files. The GIS layers were simplified to produce the KMZ files. The KMZ layers are suitable for web mapping, but not for area or boundary calculations. Boundaries could be shifted by up to 10 meters with the simplification to remove polygon vertices. For most accurate layers, download the shapefiles.

  • Segmentation GIS  KMZ
  • Combined Sewer Overflow GIS  KMZ
  • Municipal Separate Storm Sewer System (MS4) GIS  KMZ
  • Federal Lands GIS  KMZ
  • Maryland Regulated Area GIS  KMZ
  • Direct Loads GIS  KMZ (Direct Loads Include Waste Water, Rapid Infiltration Basins, Large Monitored Septic Systems, and Developed Land Spray Irrigation)

BMP Reports

Each BMP is developed following a Protocol that was approved by the Chesapeake Bay Program Partnership. The Protocol and detailed reports for each BMP are available at the links below. 

  • Protocol for the Development, Review, and Approval of Loading and Effectiveness Estimates for Nutrient and Sediment Controls in the Chesapeake Bay Watershed Model.
  • Expert Panel reports. Click on the publications tab for published reports. 
  • Simpson Weammert-Lane 2009 Report with detailed documentation of many BMPs.

BMP Names

A crosswalk of commonly-used BMP names to the CAST BMP name may be helpful in selecting the CAST BMP that best represents your management action. The NRCS practice codes and names are also available in the NRCS-CAST file.

Cost of BMPs

BMP costs are developed by contractors to the EPA and are in 2010 dollars. The original costs were reviewed with the states who provided input. Additional BMPs were approved by the Chesapeake Bay Program Partnership since the original TMDL costs were determined. The costs are available by going to the Public Reports drop down in the top menu bar and selecting Cost Profiles. You can also log in to CAST and edit the costs by creating your own Cost Profile. CAST provides costs associated with each scenario using the cost profile you select. The data available in the Cost Profiles is summarized to include only the capital, operations and maintenance and opportunity costs, without the research notes that are included in the files below.

2010 Chesapeake Bay TMDL