URBAN CATCHMENT RESPONSE TO STORM WATER RE-ROUTING

Like most urban watersheds, Pittsburgh’s urban streams experience increased storm water volume and flow during storm events. During wet weather conditions, the benefits of natural infiltration through soil substrate are bypassed. Instead, storm water nutrients and metals are routed through macro-pore networks of pipes and drains directly into receiving water. Panther Hollow watershed is 315 hectares, encompassing Schenley Park and two densely urban neighborhoods in Pittsburgh, Pennsylvania. This watershed contains two of the six remaining open stream channels in the City of Pittsburgh, Panther Hollow Run and Phipps Run. The Pittsburgh Parks Conservancy received support from the R.K. Mellon Foundation to begin the restoration of Panther Hollow by implementing pilot green infrastructure projects to restore more natural hydrologic cycling and attenuate flashy in-stream storm flows. Successful implementation of these projects to reap multiple bottom line benefits depends on water rerouting to reestablish natural attenuation processes. This research examines catchment-scale green infrastructural effectiveness using modeling approaches. Potential water quality and quantity outcomes from various combinations and arrangements of green infrastructure projects are characterized. In particular, Soil and Water Assessment Tool (SWAT) models are adapted to urban conditions and used to predict water fluxes and simulate the impacts of various land management decisions (e.g., implementation of green infrastructure) in the catchment. This work will guide project planning and provide a conceptual framework for evaluating potential green infrastructure projects.