Analysis on the integrated effects of stormwater management and economic benefits in an urban area using low impact development techniques

The application of low impact development (LID) techniques preserves the predevelopment hydrologic environment and minimizes the effects of urbanization by reducing impervious areas and increasing green areas. The LID method also utilizes decentralized stormwater management approaches that attempt to manage stormwater at the location where rainfall occurs. The purpose of this study is to demonstrate the integrated effects of the LID technique for stormwater management such as flood control, improvement of water balance, and reduction of nonpoint source pollution by comparing it with conventional development methods. The economic efficiency of the LID method was also analyzed. These analyses were conducted for the Songsan Green City in the Republic of Korea, which is the construction site for a new urban area. The results show that flood peak flow and runoff volume were decreased by 4.81% and 8.37%, respectively, by applying the LID technique. Evapotranspiration and infiltration with the LID method were increased by 1.1% and 2.6%, respectively, compared with the conventional development method. The removal efficiency for nonpoint source pollution with the LID method was also 14.6% higher than with the conventional development method. Furthermore, the construction cost of the LID method was 9% lower than the cost of the conventional development method. These results show that the LID method is superior to the conventional development method in terms of stormwater management and can also reduce construction costs.