Author(s): Puay How Tion; Siti Rohaya Jokefli; Nor Azazi Zakaria
Linked Author(s): How Tion Puay, Nor Azazi Zakaria
Keywords: Grassed swale; Aging process
Abstract: The ecological drainage systems are broadly used in a new development in Malaysia as one of the sustainable stormwater management infrastructures. However, the performance of the ecological drainage system deteriorates when subjected to the aging process. Without proper and scheduled maintenance, it may fail to perform under the design rainfall intensity thus causing overflow and temporary inundation to the surrounding area. The grassed swale system is one of the components of the Bio-Ecological Drainage System (BIOECODS) which was implemented in USM Engineering Campus in the year 2001. This system was designed to combine infiltration, delayed flow, storage and purification as pre-treatment of storm water before discharging into constructed wetlands. The grassed swale was designed to reduce the on-site peak discharge by increasing the time of concentration through infiltration process as well as mild channel slope. In this study, the on-site saturated hydraulic conductivity of the swale was used as a parameter to assess the performance of a 17-year old swale. On-site permeability tests were carried out by using the Guelph Permeameter at several locations. The result shows that some sections of the swale clearly show sign of aging as the soil condition changed from well-graded sand to sandy clay loam and the infiltration rate has significantly reduced from the intended design infiltration rate.
Year: 2018