Due to the growing development in urban areas, the percentage of impermeable ground surface is being increased substantially. The greater runoff rate and volume caused by increased impermeable surface can lower the effectiveness of rainwater sewerage system. Thus green building and water retention methods are proposed to reduce runoff in the urban areas. This study applied various water retention methods to evaluate the effectiveness of flood mitigation in urban areas. Study area was chosen as Shi-Mei watershed at San-Chong district, New Taipei City. Proposed water retention methods were applied comprehensively in National San-Chong Senior High School in the watershed to demonstrate the process and results of the flood mitigation and economic benefits. Analytical results reveal that increasing the shallow retention basin is the best way to flood mitigation in the study area, and the underground flood detention pond ranks the second. Moreover, this study conducted the cost-effective analysis and revealed the advantage of the water retention method over the traditional structural method in flood mitigation. The traditional structural method by increasing rainwater sewerage and pumping station capacity costs 355 million to increase the return period of flood protection from three years to five years in the study area. However, using the water retention methods proposed by this study costs only 66.9 million, and the water retention method is easier to be implemented than the traditional structural method is. Finally, this study proposes the use of water retention methods as a feasible and efficient approach to reducing the floods in well developed urban areas.
|Number of pages||14|
|Journal||Taiwan Water Conservancy|
|Publication status||Published - 2012 Mar|
All Science Journal Classification (ASJC) codes
- Environmental Engineering
- Water Science and Technology