雨水貯集滯洪設施政策始於國外都市治水方法,並於2013年納入「建築技術規則」實施,但未就臺灣特性及需要進行探討。對於暴雨源頭控制的蓄洪、滯洪特性,利用SWMM(Storm Water Management Model)進行分析,並以桃園市中路重劃區為案例。研究探討三種大小的設施及四種放流規範,以回歸週期5~200年、延時0.25~24小時的降雨進行分析,發現設施越大削減效果越好,設施體積若低於總降雨體積的0.3倍時,將無法發揮效果;當滯洪設施未達滿水位時,放流係數越小消減效果越佳;採蓄洪設施政策時,下游區域減作可與全區施作有相近的效果,可有效節省建設經費。
The implementation of stormwater source control facilities has been widely accepted in Taiwan and officially included by "Building Technical Regulations". Due to the difference in hydrological conditions, the strategy of this kind of facilities should be modified according to the local characteristics. For this concern, this study utilized Storm Water Management Model (SWMM) to analyze the Chung-Lu rezoning area, Taoyuan, Taiwan. This study considers three different storages and four discharge capacities of the source control facilities under various rainfall conditions. The results indicate that the larger volume of the storage facility comes with a better effect of flood peak reduction. If the storage volume is less than 0.3 times of the total rainfall volume, the retention facilities could be evidently ineffective. While the flood detention facility is not full, more flood peak reduction is expected with less discharge releasing. This study also examines the effect of regional allocation of stormwater source control facilities. It suggests that implementation of the exemptions in the downstream area could still has a similar effect as the application in the entire watershed. Appropriate consideration with spatial allocation in policy could make the implication more economical and effective.