Chrtiers Creek is 52.4 miles long with its source in Washington County. It drains a watershed area of 277 square miles. The ALCOSAN sewer system has 42 Combined Sewer Overflows and 17 Sanitary Sewer Overflows within the shed. Chartiers Creek is the largest stream, with the most opportunity for shallow water paddling, feeding the Three Rivers within the boundaries of the City of Pittsburgh.
The municipalities of Allegheny County have an additional 27 CSOs and 16 SSOs. In a typical year, the combined sewer overflows contributes 1,034 million gallons and the sanitary sewer overflows contribute 158 million gallons of sewage tainted water into the Creek.
Many of the municipalities in the Allegheny County portion of the sewershed have formed the Chartiers Watershed Municipal Alliance to tackle stormwater problems. In addition, the Lower Chartiers Watershed Association formed in 2018 "to conserve, beautify, and improve the quality of the Lower Chartiers Creek and its surrounding watershed."
As it approaches the Ohio River, Chartiers Creek creates the border between the City of Pittsburgh and McKees Rocks Borough. Sheradan Park is a major greenspace along the Creek at this border. The City of Pittsburgh recently completed a Sheradan Park Master Plan that enhances the stormwater functionality of Sheradan Creek and provides improved people-scale connections across to McKees Rocks.