The Black Watershed (HUC 07040007) covers approximately 3,800 square miles in southeastern Pennsylvania and northern Maryland. The region's hydrology is influenced by steep terrain and high annual precipitation, which can cause flash flooding. The watershed is home to several large reservoirs, including the Conowingo Reservoir, which is known for its high sediment and nutrient loads. The area is also prone to severe snowpack, with an average of 30 inches of snowfall per year. Surface water quality has been impacted by agricultural runoff and urban development. Climate change has caused an increase in extreme weather events in the region, including more frequent and intense storms. This has led to more frequent flooding and erosion in the Black Watershed. Additionally, warming temperatures have led to a decline in snowpack, which is a critical component of water supply in the region. Efforts to improve water quality and reduce pollution in the watershed are ongoing.