Water Resources Research Act Program

Details for Project ID 2018DC202B

Runoff Control Performance Evaluation and Development of Design Guideline for Green Roof Systems for District of Columbia

Institute: District of Columbia
Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $9,980 Total Non-Federal Funds: $4,790

Principal Investigators: Pradeep Behera

Project Summary: Urban stormwater management has been a very critical issue for most of the metropolitan cities in the United States. The older metropolitan cities which are serviced by both combined and separate sewer systems face severe stormwater quantity problems (i.e., flooding, overflows, sewer back up, stream bank erosion) and water quality problems (i.e., CSOs and stormwater discharges, water pollution and receiving water quality problems). The severity of the problem has been continuously emphasized due to climate change, aging drainage infrastructure and high impervious areas. The high impervious cover resulting in higher runoff volume and with faster velocities to local receiving waters through CSOs and polluted stormwater discharges. Similar to many older cities in the nation, the sewer system in the District of Columbia is comprised of both combined and separate sewer systems. It has been recognized that these systems contribute significant pollution to the Anacostia and Potomac Rivers and Rock Creek through Combined Sewer Overflows (CSOs) and Storm Sewer discharges during wet-weather (i.e., rainfall and snowmelt) events [1-3]. These overflows and associated pollutant loads can adversely impact the quality of the receiving waters. Anacostia River was determined to be one of the most polluted water bodies in the nation mainly due to the combined stormwater and municipal wastewater discharged to it during peak runoff [4]. A cost effective and sustainable way to reduce the impacts of stormwater quantity and quality has been implementation of best management practices such as low impact developments, rain barrels, green roofs, bio-retention ponds and structural runoff control etc. However due to the high cost of land in dense urban areas such as the District of Columbia it is highly desirable to minimize the land occupied by these facilities by optimizing their performance. In last few years, District has been emphasizing not only implementation of green roofs as means of runoff quantity control but also utilization of availability of number of flat roofs. The goal of the proposed research is to design and built two mobile green roof systems that will demonstrate the visualization of efficient stormwater runoff control from impervious roof surface and pervious green roof surfaces. The project will plan, design and build two benches with each having 50 square feet of roofs which will be placed at the central quadrangle within the Van-Ness campus of University of the District of Columbia. One roof will be comprising of traditional shingles depicting the impervious surface of roofs and associated runoff generation and other roof will be comprising of the green roof system depicting the conversion of impervious to pervious surface for volumetric runoff control. The systems will be equipped with runoff collection systems to visualize and understand the green roof systems. The proposed mobile green roof systems will be used for academic demonstration of stormwater runoff volume control for elementary to high school students, university students as well as public. The outcomes of this seed grant research include understanding of impact of green infrastructure such as green roof systems on the storm-water quantity and quality in the District of Columbia.