Study Of Urban Stormwater Runoff BMPs Planning With Support Of SUSTAIN System

Urbanization process brought various urban runoff problems such as increasing runoff volume, increasing peak flow, and runoff pollution, which attract more and more concerns and attentions. Traditional discharge system would no longer satisfy the sustainable urban runoff management requirements, and recently, urban runoff best management practices and low impact development with the core concept of"nature and multi-function"become more and more popular. Obviously, our country needs to learn from advanced concept and practical experiences abroad and to ameliorate our own urban runoff control and management planning system with practical case study. This study mainly focus on 2 key technical aspects under the existing urban storm water runoff control and management planning frame: establishment of urban storm water runoff Best Management Practices (BMPs) assessment criteria system and the application of storm water runoff management decision support system SUSTAIN. A college under construction in Nanhai discrict, Foshan, Guangdong province was chosen as the case study for urban storm water runoff BMP control and planning.First, based on the research of urban storm water runoff BMP study and practices both in China and abroad, the technical and economic characteristics of commonly used BMPs were analyzed and synthesized. Then an assessment system was established with criteria selected for BMPs site suitability, performance evaluation, and cost & maintenance to serve as a first screen and selection reference for the BMP planning. The latest decision support system SUSTAIN developed by USEPA was taken as the aiding tool in the planning process. The possible application and input data requirements of SUSTAIN in each stage of urban storm water runoff management planning was identified. The packed parameters with western units were also modified and localized.The new campus of Guangdong vocational and technical college on envoironmental protection which is now under construction was picked as the target test area. Based on site-visit and data collection, several BMPs suitable for the site were selected using the BMPs assessment criteria system. Then, under the frame of ArcGIS and using the BMPs Siting Tool, 3 management scenarios were designed and arranged, including a basic scenario after development, an economic BMPs scenario and a maximized performance BMPs scenario. With the actually hourly rainfull data of 2008 as input precipitation, the impact on the site and the control effects of urban storm water runoff under each scenario were calculated, analyzed and compared. In the end, according to the local control target, the planning scenario was optimized to find the most cost-effective scheme for urban storm water runoff BMP planning.