Examining the impacts of individual lot stormwater detention in a housing estate

• Published in: Asia-Pacific Journal of Science and Technology
• Main Author: Mah D.Y.S.; Ngu J.O.K.; Caroline P.D.; Malek M.A.
• Format: Article
• Language: English
• Published: Khon Kaen University,Research and Technology Transfer Affairs Division 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124769180&doi=10.14456%2fapst.2022.14&partnerID=40&md5=becfd1cd0d24c22b417a8665c859aa40

This paper describes the Storm Water Management Model (SWMM) simulations of three individual lot stormwater detention systems under the car porches of houses. These three systems consist of ready-made modular units presumably fitted under 49 m2 car porches of 204 double-story terrace houses. The 37,032 m2 housing estate is calculated to have 75% of land covered with houses, 25% with roads and other infrastructures. The housing estate was subjected to 5-minute, 10-year Average Recurrent Interval (ARI) short-duration design rainfall. The model predicted that all three systems could reduce the peak runoff at outfall from 2.79 to 0.38 m3/s. It indicated that any of the system could cause 86% reduction of the runoff for the whole housing estate. In order to differentiate the performance of the three systems, the housing lot was further investigated. When Type 1 system (1.15 m high with 49 m3 per lot) was analysed by the SWMM model, only 8% of its storage volume was filled that highlights an over design. Type 2 system (0.3 m high with 6 m3 per lot) modelled at 84% while Type 3 system (0.3 m high with 9 m3 per lot), at 54%. The difference in heights between the systems explained the low percentage of filling for the Type 1 system. Comparing Type 2 and Type 3, concrete structure within Type 3 had only half of its volume filled. In this light, the Type 2 system made of polyethylene pieces was found the most efficient in lowering post-development peak runoff. © 2022, Khon Kaen University,Research and Technology Transfer Affairs Division. All rights reserved.