This page provides links to online maps and GIS downloads to assist in implementing TMDLs. The resources below include maps of every approved TMDL (categorized by pollutant) as well as shapefiles relating to the implementation process. Two separate TMDL maps are provided for nitrogen, phosphorus and sediment; one map for those TMDLs that were developed by the state, and one map for those TMDLs which are part of the 2010 Chesapeake Bay TMDLs. All downloads are provided as zipped shapefiles.
TMDL Maps by Pollutant
TMDL Data Center Updates
Additional geographic resources for TMDL implementation
Other mapping resources