Urban Stormwater Runoff Management Using Low-Impact Development: Case Study of Portland

The adaptation of cities to recent climate change is crucial. One challenge is stormwater runoff management, which can affect urban environment and transportation. Low-impact development is a policy that emphasizes fast, cost-effective, and environmentally friendly solutions. This study aims to design a commercial complex that incorporates low-impact development strategies for stormwater runoff reduction in Portland, a high-rainfall city. The research methodology consists of three stages. Firstly, standard rainfall data is analyzed using SWMM software. Secondly, an urban plan is developed, which includes the design of a commercial complex that incorporates rainwater management and the reduction of stormwater runoff based on low-impact development policies. Finally, the simulated data generated by the proposed design is re-analyzed using SWMM software, and the final results are compared. The research findings indicate that all three sub catchments in the studied site have a high potential for runoff. Furthermore, the results demonstrate that the implementation of low-impact development strategies, such as roof gardens, permeable pavement, and biological preservation materials, can reduce runoff by 35%, and save or reuse 40% of the rainwater. These findings provide valuable insights for private and public stakeholders, encouraging them to incorporate low-impact development policies into urban plans, particularly in Portland, to enhance runoff management and water conservation.