THE recent flash floods in Shah Alam, which turned roads into streams and submerged parked vehicles in muddy water, took precedence at the Shah Alam City Council (MBSA) full board meeting on Wednesday (Oct 27).
In his speech, Shah Alam mayor Datuk Zamani Ahmad Mansor (pic) said the council viewed the matter seriously for the considerable damage that it can cause in terms of work downtime and property loss.
“In the latest flood incident which took place on Oct 20 for example, post-clean up works took three days where 590.57 tonnes of rubbish had to be removed from affected areas,” he said.
He explained that one of the causes behind the flash floods was the inability of the city’s current pump systems to deal with the discharge of stormwater into the river whenever there is an occurrence of extraordinary heavy rainfall.
In the recent floods, which had come about after a five-hour rainfall, the Drainage and Irrigation Department (DID) measured the downpour at 148mm and the heaviness of its flow had a reading of 34 ARI (average recurrence interval).
The city’s existing pump systems can only accommodate a capacity of up to 20 ARI. For the record, all pumps were functioning properly and the council contractor who maintained the pumps was on site at the time of the incident.
“As such the council has allocated close to RM4mil to provide 12 temporary pumps to be installed at Sections 13, 25 and U1. This allocation will also include the building of temporary retention ponds in Section 34,” said Zamani.
As an immediate measure, eight additional support pumps will be rented first to increase the capacity of the existing ones in Sections 4, 10 and 13 for the rainy season. Their retention ponds will also be checked to ensure they are functioning properly and rubbish in the drains removed so as not to obstruct water flow.
For the long-term, the Engineering Department will design and build a dual function pool in Section 6 to fulfill flood management requirements as well as be used for recreational purposes. In Section 4, a bypass channel to divert water flow will be built and the existing drains and flap gates repaired.
In addition to flood monitoring systems to be installed at identified hotspots, a sustainable drainage master plan will also be carried out for Sungai Renggam. The study will involve internal and external drain systems as well as flap gates.
For Section 34, upgrades will be carried out on existing land drains at Jalan Stereng 34/6 and Jalan Hon 34/10 in Taman Perindustrian Bukit Kemuning.
A flood study is being carried out by consultants in Sections 13, 25, 32, 36 and U1 to find out what maintenance and upgrades will be required for better flood management. One identified requirement is the use of sirens to warn of impending floods at hotspots. MBSA will work with DID for the installation of sirens.
On whether MBSA has considered upgrading its drainage and retention pond systems or that specifications for infrastructure in future developments must meet with weather challenges such as the tidal phenomenon which has increased in frequency of late, Zamani said that the expense of such an exercise will ultimately fall back on the taypaying public.
“This is why we are pushing towards sustainable development goals in cities to reduce carbon emissions which has led to global warming and extreme weather change in the first place,” said Zamani.
He also wanted to point out that the cause of floods was also due to the presence of rubbish which had hampered stormwater drain off in the city’s waterways.
“On this point, the public can help lessen the occurrence of flash floods by simply not littering,” he said.