Prince George's County

Watersheds and Total Maximum Daily Load (TMDL) within Prince George’s County

Prince George’s County (the County) has multiple watersheds. Environmental scientists classify watersheds by geographic levels. For instance, The Chesapeake Bay watershed covers multiple states. The Lower Beaverdam Creek watershed (part of the Anacostia River watershed) is a small part of the Chesapeake Bay watershed. The state of Maryland has identified 12 watersheds that are entirely in or part of the County (map to left). The Chesapeake Bay Program model categorizes the County’s watersheds differently into 11 watersheds (map to right). Maryland developed local total maximum daily loads (TMDLs) using both categorizations, in addition to finer-scaled subwatersheds, especially in the Anacostia River watershed.

Watersheds in Prince George's County

Map of Maryland watersheds within the County
Map of Maryland watersheds within the County
Map of Chesapeake Bay Program watersheds within the County
Map of Chesapeake Bay Program watersheds within the County

TMDL Factsheets

The Maryland Department of the Environment (MDE) provides a list of Maryland waters with TMDLs, including the basin name, approved TMDL documents and implementation plans, DNR 8-digit basin number, and the impairment (e.g., nutrients, sediment, and bacteria).

The following factsheets summarize each U.S. Environmental Protection Agency (EPA)-approved TMDL in the County (see Introduction for definition of TMDL). Click on the name of the pollutant below to view the TMDL factsheet. Complete TMDL reports may be obtained from the MDE TMDL website.

Anacostia River

Chesapeake Bay Watershed

Middle Patuxent River

Lower Patuxent River

Mattawoman Creek

Patuxent River

Piscataway Creek

Rocky Gorge Reservoir

Potomac River

  • PCBs (Tidal Anacostia River and Potomac River)

Upper Patuxent River

Western Branch

TMDL Stormwater Implementation Resources

The County’s MS4 requires the County to develop watershed implementation plans (WIPs) within one year of EPA approving the TMDL. MDE developed guidance documents and tools to aid local governments municipalities in developing their WIPs.

MDE TMDL Implementation Guidance

In 2022, MDE’s Water and Science Administration released technical guidance documents to help local Maryland jurisdictions develop their watershed implementation plans.

  • Accounting for Stormwater Wasteload Allocations and Impervious Acres Treated: Guidance for National Pollutant Discharge Elimination System Stormwater Permits (November 2021)
  • General Guidance for Local TMDL (Total Maximum Daily Load) Stormwater Wasteload Allocation (SW-WLA) Watershed Implementation Plans (WIPs) (February 2022)
  • Guidance for Developing Local Nutrient and Sediment TMDL (Total Maximum Daily Load) Stormwater Wasteload Allocation (SW-WLA) Watershed Implementation Plans (WIPs) (March 2022)
  • TMDL Implementation Progress and Planning (TIPP) Tool (Original version: June 2021, Most recent version: April 2022)
  • Guidance for Developing Bacteria Total Maximum Daily Load Stormwater Wasteload Allocation Watershed Implementation Plans (February 2022)
  • Guidance for Developing Local PCB TMDL (Total Maximum Daily Load) Stormwater Wasteload Allocation (SW-WLA) Watershed Implementation Plans (WIPs) (August 2022)

TMDL Implementation Toolkit

Local jurisdictions can use several available implementation tools to support TMDL implementation.