Using the Hydrologic Footprint Residence to Evaluate Low Impact Development in Urban Areas

Abstract

Urbanization adversely impacts the health of a watershed and the receiving water body, as increased runoff volumes, velocities, and peak flows cause erosion, flooding, and degradation of ecosystem habitats. Low Impact Development (LID) strategies are used to mitigate the impacts of urbanization by reducing the runoff at the source and restoring the natural hydrologic flow regime. Rainwater harvesting, permeable pavements and green roofs may be placed in urban areas to mitigate the runoff generated from rooftops and parking lots. This study simulates and evaluates the placement of these LID strategies for an urban watershed on the Texas A&M University campus. A conventional metric, the peak flow, is used to evaluate the hydrologic performance of LID, in addition to the Hydrologic Footprint Residence (HFR), which is a new metric that captures the inundated areas and duration of floods in downstream reaches. The results indicate that HFR can be used to evaluate the hydrologic performance of LID as it captures both changes in runoff volumes and the duration of flooding to represent the impacts of urbanization.