Abstracts of presentations given in Session 2 of the 2009 UCOWR conference


In response to water quality concerns in the Jordan Lake Reservoir and state and federal mandates, several cities in North Carolina are being required for the first time to reduce nutrient loads in stormwater from previously developed lands; that is, install retrofits. It is anticipated that similar requirements will become necessary for other urban areas as North Carolina. The goal of this study is to evaluate the feasibility of alternative approaches to stormwater management for existing developments within North Carolina cities. Evaluated alternatives include retrofitting onsite best management practices, off-stream treatment along mainstems of the urban drainage network, stream restoration, and alteration of stream corridors as urban greenways, among others. Geographic coverage of the study includes seven cities of the WRRI Urban Water Consortium Stormwater Group. Stormwater drainage networks at the citywide/watershed scale will be related to existing land use, land use plans, and zoning classes. Feasibility of alternatives will be measured by the cost-effectiveness of alternative practices in reducing peak flows and pollutant loads (nutrients and sediment) and the potential for ecological restoration. Two spatial scales will be used for feasibility analysis: One will focus on tributary watersheds at a scale of 260-520 hectares (1-2mi2), and one watershed from each of the cities will be selected with priority given to watersheds draining to impaired water bodies. The feasibility of retrofitting onsite BMPs within these watersheds will be evaluated. The second scale will focus on mainstems of drainage networks in one selected watershed to determine the feasibility of using larger off-stream management practices and improving stream corridor management.