The Patapsco River Mesohaline (PATMH) Tidal Chesapeake Bay Segment is a tidal estuary, or embayment, located on the western shore of the Chesapeake Bay. The total watershed draining to PATMH covers 1,514 square kilometers (km2) (374,040 acres) and spans Baltimore City, Carroll, Howard, Anne Arundel, and Baltimore Counties. Only two specific segments within the PATMH are listed as impaired for trash – the Middle Branch and the Northwest Branch. More specifically, the “Middle Branch from the mouth (Ferry Bar Park to Harbor Hospital Center) extending westward and the Northwest Branch from the Hull Street Pier to Canton Waterfront Park.” This impaired shoreline receives drainage from three distinct Maryland 8-digit watersheds: Baltimore Harbor, Gwynns Falls, and Jones Falls, all within Baltimore City and Baltimore County. Approximately 5,700 acres of the MD 8-digit Baltimore Harbor watershed drain to the impaired shoreline. The entire Gwynns Falls watershed (approx 42,000 acres) drains to the Middle Branch impairment and the entire Jones Falls watershed (approx 37,000 acres) drains to the Northwest Branch impairment. All three contributing watersheds are highly urbanized, with mainly residential and commercial areas, especially within Baltimore City. The northern portions of both the Gwynns Falls and Jones Falls in Baltimore County include more forest land use as well as small amounts of crop land. The combined population of the three watersheds is approximately 725,000.
The document, available below, approved by the U.S. Environmental Protection Agency (EPA), establishes a Total Maximum Daily Load (TMDL) for trash and debris in the Northwest Branch and Middle Branch portions of the PATMH Tidal Chesapeake Bay Segment (Middle Branch/Northwest Branch) (2012 Integrated Report of Surface Water Quality in Maryland Assessment Unit ID: MD-PATMH-MiddleBranch_NorthwestBranch). More specifically, the listing is limited to the shoreline of the “Middle Branch from the mouth (Ferry Bar Park to Harbor Hospital Center) extending westward and the Northwest Branch from the Hull Street Pier to Canton Waterfront Park.”
Total Maximum Daily Loads of Trash and Debris for the Middle Branch and Northwest Branch Portions of the Patapsco River Mesohaline Tidal Chesapeake Bay Segment, Baltimore City and County, Maryland
Approved on January 5, 2015
EPA's Decision Letter (9764KB)
Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.
1800 Washington Boulevard, Baltimore, MD 21230