Final TMDLs Approved by EPA: South River

​The South River watershed is located entirely within central Anne Arundel County, Maryland. The watershed is located in the Coastal Plain eco-region, identified in the Maryland Department of Natural Resources (MDDNR) Maryland Biological Stream Survey (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 36,200 acres, not including water/wetlands. Approximately 300 acres of the watershed area is covered by water. The total population in the South River watershed is approximately 75,800.  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 South River 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
South River watershed on the State’s 2014 Integrated Report as impaired by multiple pollutants. The South River is associated with two assessment units in Maryland’s Integrated Report: a non-tidal 8-digit watershed (02131003) and an estuary portion (Chesapeake Bay segment South River Mesohaline). A data solicitation for TSS/sediment was conducted by MDE in August 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 South River watershed, and more specifically, at a level to support aquatic life. The TMDL, however, will not completely resolve the impairment to biological communities within the watershed. Since the BSID watershed analysis identifies other possible stressors impacting the biological conditions (e.g. chlorides), an additional TMDL or TMDLs may be needed to fully address the impacts to biological communities. 

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

(Approved on September 28, 2017)

EPA's Decision Letter EPA's Decision Letter (991KB)
​Fact Sheet South_River_Sed_TMDL_FactSheet.pdf (391KB)
Main Report

South_River_Sed_TMDL_final.pdf (1904KB)

Point Source Technical Memorandum South_River_Sed_TMDL_PS_TechMemo.pdf (34KB)
Nonpoint Source Technical Memorandum South_River_Sed_TMDL_NPS_TechMemo.pdf (26KB)
Comment Response Document South_River_Sed_TMDL_CRD.pdf (29KB)

Additional Supporting Information

Biological Stressor Identification South River Watershed Report (589KB)

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.