Final TMDL Approved by EPA: West River Watershed

The West River watershed is located on the lower western shore of Maryland in Anne Arundel County. The West River watershed is comprised of two major tributaries, the West and Rhode Rivers. According to the Chesapeake Bay Program’s Phase 5.3.2 watershed model the drainage area of the Maryland 8-digit watershed is approximately 16,300 acres. The Maryland 8-digit watershed boundary also includes approximately 3,550 acres of tidal water. The watershed is located in the Coastal Plain region, one of three distinct eco-regions identified in the Maryland Dept. of Natural Resources-Maryland Biological Stream Survey (MDDNR MBSS) Index of Biological Integrity (IBI) metrics. The total population in the West River watershed is approximately 10,000. There are no “high quality,” or Tier II, stream segments (Benthic-IBI and Fish-IBI aquatic life assessment scores > 4 [scale 1-5]) located within the West River watershed. Tier II segments would require the implementation of Maryland’s anti-degradation policy.
The West River watershed is associated with three assessment units in Maryland’s Integrated Report: a non-tidal 8-digit watershed (02131004) and two estuarine portions [West River Mesohaline (WSTMH) and Rhode River Mesohaline (RHDMH)]. Sediment TMDLs for the WSTMH and RHDMH were established as part of the Chesapeake Bay TMDLs in 2010. Background information on the tidal portion of the watershed is presented for informational purposes only. A data solicitation for TSS was conducted by MDE in March 2018, 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 non-tidal West River watershed, and more specifically, at a level to support aquatic life. 

Total Maximum Daily Load of Sediment in the Non-tidal West River Watershed, Anne Arundel County, Maryland

(Approved on April 24, 2019)

EPA's Decision Letter EPA's Decision Letter (5093KB)
​Fact Sheet West_River_Sed_TMDL_FactSheet.pdf (343KB)
Main Report

West_River_Sed_TMDL_final.pdf (1686KB)

Point Source Technical Memorandum West_River_Sed_TMDL_PS_TechMemo.pdf (230KB)
Nonpoint Source Technical Memorandum West_River_Sed_TMDL_NPS_TechMemo.pdf (217KB)
Comment Response Document West_River_Sed_TMDL_CRD.pdf (201KB)

Additional Supporting Information

Biological Stressor Identification West River Watershed Report (452KB)

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.