Watershed Protection & Restoration

Storm Water Management Inventory and Watershed Implementation Plan

On December 29, 2010, the U.S. Environmental Protection Agency (EPA) established the Chesapeake Bay Total Maximum Daily Load (TMDL).  The TMDL is a historic and comprehensive "pollution diet" to restore clean water in the Chesapeake Bay and the region’s streams, creeks, and rivers (U.S. EPA).  In order to meet the US EPA Chesapeake Bay TMDLs, the Maryland Department of the Environment (MDE) is expected to issue a new Phase II National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) General Permit.  The Phase II General Permits are required for municipalities with populations between 1,000 and100,000.  This new Phase II General Permit will require the City of Annapolis (the City) to meet the Chesapeake Bay TMDLs for total nitrogen, total phosphorus, and total suspended solids.  This upcoming Phase II permit is also expected to require treatment of 20 percent of impervious surfaces in the City by 2025. 

This Stormwater Management Inventory, was developed to assess the City’s progress toward treating 20 percent of impervious surfaces based on previously implemented stormwater management features or best management practices (BMPs).  To determine the areas that are currently treated in the City, information was collected on previously implemented BMPs and input into the this GIS database.  As part of the City’s Watershed Improvement Plan (WIP), this inventory identified 741 existing stormwater BMPs. This mapping tool will allow you to view  existing BMPs throughout the City.

To view stormwater quality improvements throughout the City of Annapolis, visit our Stormwater GIS Map


Improvement Plan Documentation