Retrofit of a Pervious Pavement System to Improve Storage Control in a Combined Sanitary Sewershed

The City of Omaha Public Works Department is concerned about the effectiveness of pervious pavement to improve water quality and mitigate peak flow rates in developed watersheds. Pervious pavement can be designed with various components including detention storage volume, an underdrain, and an overflow. The effectiveness of a pervious pavement system for volume control may be limited based on lack of understanding with these design components. The City of Omaha built a 3480 m2 parking lot of which 1497 m2 was pervious pavement as a demonstration project at a local police precinct. While the City of Omaha was well intentioned by building green infrastructure components into their stormwater runoff management, these early implementations provided filtration of runoff but offered little in the way of rate or volume control for the combined sewer system. Consequently, a retrofit was planned to integrate real-time controlled release valves on outlets that would respond to current weather and sewer system conditions. It is estimated that this level of control will increase on site performance to greater than 90% management of annual runoff rate and volume. This effort is part of the Water Environment Research Foundation (WERF) Pilot Site Testing Initiative for High Performance Green Infrastructure Targeted Collaborative Research Project.