Final TMDL Approved by EPA: Other West Chesapeake Bay Watershed

​The Other West Chesapeake Bay watershed is part of the Lower Western Shore tributary basin. The Lower Western Shore tributary basin drains approximately 270 square miles of land, including portions of Anne Arundel and Calvert Counties located on the Western Shore of the Chesapeake Bay. Large water bodies in the tributary basin include the Magothy, Severn, South, West and Rhode Rivers. The Other West Chesapeake Bay Drainage basin is located in the lower part of this tributary basin and has no major rivers. The watershed is entirely located within the Coastal Plains physiographic region. Coastal Plains is one of the three distinct eco-regions identified in the MDDNR MBSS Index of Biological Integrity (IBI) metrics.  According to the Chesapeake Bay Program’s Phase 5.3.2 watershed model, the total drainage area of the Maryland 8-digit watershed is approximately 51,170 acres, not including water/wetlands. Approximately 505 acres of the watershed area is covered by water. The total population in the Other West Chesapeake watershed is approximately 38,750. There are no “high quality,” or Tier II, stream segments (BIBI and FIBI aquatic life assessment scores > 4 [scale 1-5]) located within the Other West Chesapeake watershed. Tier II segments would require the implementation of Maryland’s anti-degradation policy. 

The Maryland Department of the Environment (MDE) identified the waters of the Other West Chesapeake watershed on the State’s 2014 Integrated Report as impaired by multiple pollutants. The Other West Chesapeake watershed is associated with two assessment units in Maryland’s Integrated Report: a non-tidal 8-digit watershed (02131005) and an estuary portion (Chesapeake Bay segment: Middle Chesapeake Bay Mesohaline – CB4MH).  A data solicitation for TSS/sediment was conducted by MDE in November 2016, and all readily available data have been considered.

The TMDL, available below, will ensure that watershed sediment loads are at a level to support the designated uses for the Other West Chesapeake Bay watershed, and more specifically, at a level to support aquatic life. 

Total Maximum Daily Load of Sediment in the Non-tidal Other West Chesapeake Watershed, Anne Arundel and Calvert Counties, MD

(Approved on February 9, 2018)

EPA's Decision Letter EPA's Decision Letter (9156KB)
​Fact Sheet West_Chesapeake_Sed_TMDL_FactSheet.pdf (236KB)
Main Report

West_Chesapeake_Sed_TMDL_final.pdf (1322KB)

Point Source Technical Memorandum West_Chesapeake_Sed_TMDL_PS_TechMemo.pdf (46KB)
Nonpoint Source Technical Memorandum West_Chesapeake_Sed_TMDL_NPS_TechMemo.pdf (33KB)
Comment Response Document West_Chesapeake_Sed_TMDL_CRD.pdf (35KB)

Additional Supporting Information

Biological Stressor Identification Other West Chesapeake Watershed Report (466KB)

Biological Stressor Identification Methodology (459KB)

Nontidal Sediment TMDL Methodology Report (361KB)

Addendum to the Nontidal Sediment TMDL Methodology Report (23KB)


Contact Information

Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.