Final TMDL Approved by EPA: Upper Chester River Watershed

The Upper Chester River and its tributaries are part of the Chester River basin that drains to the Chesapeake Bay. The Upper Chester River watershed covers 178 square miles in Maryland and Delaware. About 137 square miles of the Upper Chester River watershed are in Maryland, which includes 82 square miles in Queen Anne’s County and 55 square miles in Kent County. Upper Chester River is approximately 16.9 kilometers (10.5 miles) in length and extends from the headwaters in Delaware downstream to the confluence with Foreman Branch, and the Middle Chester watershed extends from that point downstream to the confluence with Southeast Creek. The upper region of the Upper Chester River Watershed, near the Maryland and Delaware border, consists of uninhabited forests and wetlands, which are part of the Millington Wildlife Management Area. This is an area of approximately 3,800 acres, which drains into Cypress Branch, northeast of Millington. The Upper Chester River watershed is agriculturally diverse and high in the production of corn, wheat and soybean. The watershed area is located in the Coastal region of three distinct eco-regions identified in the Maryland Biological Stream Survey (MBSS) 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 86,500 acres, not including water/wetlands. Approximately 300 acres of the watershed area is covered by water. The total population in the Upper Chester River watershed is approximately 7,200.
There are eight “high quality,” or Tier II, stream segments located within the Upper Chester 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 Upper Chester River watershed is associated with two assessment units in Maryland’s Integrated Report: a non-tidal 8-digit watershed (02130510) and an estuary portion [Upper Chester River Tidal Fresh (CHSTF)]. This TMDL only addresses sediment loads in the non-tidal portion of the watershed. Upstream loads from the non-tidal Delaware Chester River discharge into the non-tidal 8-digit watershed and are included in this TMDL. A sediment TMDL for the CHSTF was 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. Only a baseline load and load allocation have been calculated for the Delaware Chester River.
The TMDL, available below, only addresses the non-tidal portion of the watershed. Sediment TMDLs for the tidal estuaries were established as part of the Chesapeake Bay TMDLs in 2010. 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 Upper Chester River watershed, and more specifically, at a level to support aquatic life. 

Total Maximum Daily Load of Sediment in the Non-tidal Upper Chester River Watershed, Kent and Queen Anne's Counties, Maryland

(Approved on April 8, 2019)

EPA's Decision Letter EPA's Decision Letter (5000KB)
​Fact Sheet Upper_Chester_Sed_TMDL_FactSheet.pdf (357KB)
Main Report

Upper_Chester_Sed_TMDL_final.pdf (2000KB)

Point Source Technical Memorandum Upper_Chester_Sed_TMDL_PS_TechMemo.pdf (232KB)
Nonpoint Source Technical Memorandum Upper_Chester_Sed_TMDL_NPS_TechMemo.pdf (218KB)
Comment Response Document Upper_Chester_Sed_TMDL_CRD.pdf (207KB)

Additional Supporting Information

Biological Stressor Identification Upper Chester River Watershed Report (KB)

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.