A large part of the watershed of Darby Creek is on developed land, and many suburbs of Philadelphia are in the watershed. The majority (61%) of the land use is considered residential, while 11% is undeveloped and 10% is open space. Of the remaining land, most of it is considered industrial, commercial, and institutional, with 2.45% classified as paved. Estimates for the population of the watershed range from 484,000 to 500,000. In general, the topography of the watershed consists of rolling land that is densely settled. A large undeveloped tract of land owned by the Delaware County Industrial Development Authority is located at the mouth of the creek.