Final TMDL Approved by EPA: Upper Choptank River Watershed

The Upper Choptank watershed is approximately 256 square miles and is part of the 6-digit Choptank River basin. The Upper Choptank extends through three Maryland counties and also into Delaware. The majority of the Maryland 8-digit watershed is located in Talbot and Caroline Counties, with only 3 square miles within Queen Anne’s County. The headwaters originate in Delaware and flow in a southwesterly direction into Maryland east of the town of Goldsboro. Once in Maryland it flows predominately in a southerly direction through the towns of Greensboro and Denton. The Upper Choptank River is tidal throughout its navigable reach, which extends from its boundary with the Lower Choptank River watershed for approximately 35 miles upstream to an area north of the Town of Greensboro.
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 159,000 acres, not including water/wetlands. Approximately 700 acres of the watershed area is covered by water. The total population in the Upper Choptank River watershed is approximately 7,200. There are eight “high quality,” or Tier II, stream segments located within the Upper Choptank River watershed. Tier II segments are designated using MBSS data, and both the FIBI and BIBI values must be greater than 4.00 (on a scale of 1 – 5). Tier II segments require the implementation of Maryland’s anti-degradation policy which is designed to prevent degradation of high quality waters. The policy requires a review of all permitted activities upstream of Tier II stream segments.
The Maryland Department of the Environment (MDE) identified the waters of the
Upper Choptank River watershed and associated assessment units on the State’s 2018 Integrated Report as impaired by multiple pollutants inlcuding sediment. The upstream Delaware Choptank River is not listed by Delaware as impaired by sediment, but is prescribed sediment reductions in this TMDL at the State boundary in order to meet the Maryland TMDL.  A data solicitation for sediment was conducted by MDE in March 2018, and all readily available data has been considered.
The TMDL, available below, will ensure that watershed sediment loads are at a level to support the designated uses for the Upper Choptank River Watershed, and more specifically, at a level to support aquatic life. 

Total Maximum Daily Load of Sediment in the Non-Tidal Upper Choptank River Watershed, Caroline, Talbot and Queen Anne's Counties, MD

(Approved on October 31, 2019)

EPA's Decision Letter EPA's Decision Letter (4789KB)
Fact Sheet Upper_Choptank_River_TMDL_FactSheet.pdf (334KB)
Main Report

Upper_Choptank_River_Sed_TMDL_final.pdf (1810KB)

Point Source Technical Memorandum Upper_Choptank_River_Sed_TMDL_PS_TechMemo.pdf (240KB)
Nonpoint Source Technical Memorandum Upper_Choptank_River_Sed_TMDL_NPS_TechMemo.pdf (220KB)
Comment Response Document Upper_Choptank_River_Sed_TMDL_CRD.pdf (241KB)

Additional Supporting Information

Biological Stressor Identification Upper Choptank River Watershed Report (374KB)

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.