Township and was manufactured to form "Darby Creek scythe stones" in the 1860s. Darby Creek tends to be a fast stream with some riffles. There is also whitewater in places. The creek is a "radically intermittent storm drain" in its upper reaches and a tidal estuary in its lower reaches. It passes through the only substantial tidal wetlands in Pennsylvania. There used to be three small dams on Darby Creek. Going downstream, their heights were , , and . However, they were removed in late 2012 because they were contributing to flooding in the area and blocking fish passage. During several measurements in the 2000s, the water temperature of Darby Creek at Foxcroft ranged from . The air temperature in the area ranged from . The barometric pressures range from 759 to 762 mm Hg. The average annual rate of precipitation in the watershed of Darby Creek is between . Soil Three soil associations exist in the Darby Creek watershed. The Neshaminy-Lehigh-Glenlg soil association is prevalent in the northwest part of the watershed. It consists of silty, well drained, gravelly, and deep soil that rests on gabbro and granodiorite bedrock. The Chester-Glenlg-Manor soil association is prevalent throughout the watershed except in its lower reaches. It consists of silty, channery, and shallow to deep soil that rests on brown schist and gneiss bedrock. The Urban Land-Wetbrook-Pitts soil association is prevalent in the southern part of the watershed. It consists of silty, sandy, and deep soil that rests on coastal sediments. Roughly 53% of the land in the Darby Creek watershed is classified as having slightly erodible soil. Watershed The watershed of Darby Creek has an area of . A total of are in Chester County, are in Montgomery County, are in Delaware County, and are in Philadelphia. Darby Creek's watershed is often referred to as the "Darby-Cobbs watershed" since its largest tributary, Cobbs Creek, drains a total area of , or approximately one third of the Darby Creek watershed. The watershed is part of the Lower Delaware drainage basin. Neighboring major watersheds are Crum Creek to the west and the Schuylkill River to the east. The creek serves as the county line between Delaware County and Philadelphia County for a reach of . The creek's mouth is in the United States Geological Survey quadrangle of Bridgeport. However, its source is in the quadrangle of Valley Forge. The creek also passes through