Water Quality Analyses (WQA) with EPA Concurrence of MDE's Findings: Lower Gunpowder River

The Lower Gunpowder Falls Watershed is located in the central eastern portion of Baltimore County, Maryland.  The Loch Raven Dam divides the Loch Raven Watershed from the Lower Gunpowder Falls Watershed.  The watershed begins at the Loch Raven Reservoir Dam and flows generally towards the east.  Where it meets the tidal portions of Gunpowder River, it becomes the Gunpowder River watershed.  The watershed is approximately 46 square miles.  

The Lower Gunpowder Falls Watershed (basin code 02130802), located in Baltimore County, was identified on the 2010 Integrated Report as impaired by nutrients (1996 listings); and impacts to biological communities—1st through 4th order streams (2006 listing). 

The report available below provides an analysis of recent monitoring data to address whether or not the watershed is still impaired by nutrients. The study demonstrates that both applicable criteria for nutrients and the designated uses supported by this criteria are being met in the Lower Gunpowder Falls 8-digit basin; therefore, a nutrient TMDL is not required.

Although the waters of the Lower Gunpowder Falls do not display signs of eutrophication, the State reserves the right to require future controls in the Lower Gunpowder Falls watershed if evidence suggests nutrients from the basin are contributing to downstream water quality problems. Other substances not addressed at this time, but identified on Maryland’s 303(d) list as impairing the Lower Gunpowder Falls 8-digit basin, will be addressed in the future. 

WQA of Eutrophication for the Lower Gunpowder Falls watershed, Baltimore County, Maryland

(EPA Concurrence: May 18, 2012)

EPA's Decision Letter EPA's Decision Letter

Main Report 

Lower_Gunpowder_NutWQA_final_12-15-2011 (1700KB)

Comment Response Document

Lower_Gunpowder_NutWQA_CRD_12-15-2011 (40KB)

Contact Information

Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.