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. 

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 details associated with costs of the the original BMPs and the more recently added BMPs are provided in the downloadable files below. The costs are also available by logging in to CAST and going to the Cost Profiles. There is a profile for each state. CAST users may edit costs to their liking and determine the cost for any scenario.

2010 Chesapeake Bay TMDL