Abide by DID’s stormwater manual, developers urged


PETALING JAYA: The Institution of Engineers, Malaysia (IEM) has urged developers to comply with the government’s Urban Stormwater Management Manual for Malaysia (MSMA) following severe floods that hit Penang and Kedah over the weekend.

Its president, Tan Yean Chin, said increasing flood run-off from urban development projects could be reduced by having flood detention ponds or equivalent systems.

He said the MSMA, which are guidelines published by the Department of Irrigation and Drainage (DID) in 2000, also emphasised on soil embankment erosion and sediment control during the construction period.

“If the control measures are not effective, large amounts of soil can be eroded and washed away from the worksites into the river systems,” he said.

“This can lower the flood-carrying capacity due to reduction of the river flow section by sedimentation,” he said in a statement today.

Tan also said climate change should also be considered in all the development and flood mitigation measures by assessing its impact and the country’s resilience in facing the changes.

He said the National Hydraulic Research Institute Malaysia’s (Nahrim) “Technical Guide on Estimation of Future Design Rainstorm under the Climate Change Scenario in Peninsular Malaysia” was a good reference in this regard.

He said many locations in Penang and Kedah had exceeded the 100-year Average Recurrence Interval (ARI), which measures the likely occurrence of a flood event.

He said two previous prominent events to also exceed the 100-year ARI were the flooding in Johor at the end of 2006 and beginning of 2007, as well as the floods in Kelantan and Pahang at the end of 2014.

“IEM would like to propose that the government implement a comprehensive and integrated flood mitigation master plan to cater for the development planning in the affected states,” he said.

“The master plan should include the flood mitigation and prevention action plans for current and future developments.”

Seven people were reported to have died in the rainstorm in Penang that began on Saturday evening and lasted till the pre-dawn hours of Sunday, resulting in floods, landslides and uprooted trees.

Earlier today, Natural Resources and Environment Minister Wan Junaidi Tuanku Jaafar said RM1.04 billion had been spent on flood mitigation projects in Penang under the 9th to the 11th Malaysia Plans.

He said the DID would review the level of protection involved in designing flood mitigation projects. This will be included in subsequent Malaysian five-year development plans.

“We also need to build sea walls and flood retention ponds, if there is available land, to reduce the flood problem,” he said.