Integrating Green Infrastructure into a Combined Sewer Service Area Model

Abstract

The Kansas City demonstration project on the use of green infrastructure to minimize combined sewer overflows (funded by the US EPA and supported by a wide range of national and local agencies) will use a variety of integrated practices and modeling approaches. This extensive project will collect data before, during, and after implementation of a variety of control practices in a 100 acre test watershed, and in a parallel control site. The reduction of discharges to the drainage system during wet weather will be calculated using models and verified through field monitoring. The continuous models will determine the decreased amount of stormwater discharged for each event as the storage and infiltration facilities dynamically fill and drain over an extended period of time. Introduction The US EPA’s Office of Research and Development’s National Risk Management Research Laboratory has funded this research element in support of its Water Supply and Water Resources Division’s AWI Research Program. “This project will evaluate, at full-scale, the integration of green infrastructure technology (e.g., engineered bioretention, rain gardens) with conventional CSO control (gray infrastructure) to gain a better understanding and develop guidance on planning, design, costs and implementation.” The intent of this project is to evaluate the water quality and quantity improvement benefits of a large-scale application of green infrastructure control practice retrofits in an entire monitored subcatchment. These green infrastructure controls have been shown to, when implemented and maintained properly, increase retention at the runoff source. This decreases the runoff volume entering the drainage system and the demand on a drainage system. Both developed stormwater and combined sewersheds can benefit from the added storage from areas retrofitted with bioretention cells or rain gardens and other management practices, e.g., inlet retrofits or curbcuts with tree plantings. This project will document an effort by the ORD to demonstrate the efficacy of implementing integrated, green infrastructure-based solutions to support control of wet-weather flow pollution problems in an urban core neighborhood within a combined sewer system. This pilot project is part of a larger adaptive management approach to incorporate Green Solutions into the Kansas City, MO CSO long-term control plan. The project involves local and regional efforts to provide the “basis-for-success” of the implementation of Green Solution infrastructure and stormwater management at the neighborhood, watershed, and regional