Mitigating the perennial flood problem
Joseph Wong &  

OF late, news coverage has mostly shown grim images of flood-damaged homes, cars and properties which devastated Penang, and to a lesser extent, Kedah and Negri Sembilan among others.

The inevitable finger-pointing has already started as to who is responsible. Of course, the easiest is to blame Mother Nature for the excessive rainfall.

However, state governments, local authorities or errant developers and contractors are also often blamed.

While there is much overlap in terms of where responsibility lies, it can broadly be said that flood mitigation planning is within the scope of town planners, developers and architects, while implementation is within the domain of contractors.

“Flooding is a major concern for us as it can bring all work on a project site to a standstill.

“It can also cause additional logistical and safety issues as materials and site elements such as scaffoldings need to be reinspected," says Master Builders Association Malaysia president Foo Chek Lee.

He says in terms of mitigation, contractors usually build temporary drainage channels which direct excess water to retention ponds. From there, it is filtered before being safely discharged.

However, poor maintenance may leave drainage channels clogged. This problem was highlighted in reports as contributing to the flash floods on Oct 30, along the Federal Highway off Bangsar South.


No excuses

Gamuda Land Sdn Bhd chief operating officer Ngan Chee Meng tells FocusM that there is no excuse for developers denying they are unaware of which areas are prone to flooding.

“Local councils provide developers with a 100-year record of floods. So unless the event is something that falls outside of the 100-year time frame, due to an adverse change in climate or non-seasonal rainfall, developers have no excuse,” he says.

For development projects, the regulation pertaining to flood mitigation measures is the Urban Stormwater Management Manual for Malaysia (MSMA) by the Department of Irrigation and Drainage. It serves to control surface runoffs from a development site.

During construction activities, a stormwater Erosion and Sediment Control Plan (ESCP) is enforced as part of the development order issued by the local authority.

The ESCP is a plan that details temporary measures implemented during construction activities to minimise the adverse effects of sediment transport from on-site to off-site areas.

Ngan says there could be some developers who will attempt to avoid building sufficient drainage to save cost. But he points out that local councils would be quick to “come down hard on them”.

On the flipside, sometimes developers go the extra mile or come up with innovative ideas for flood mitigation, he says.

However, such measures inadvertently increase the construction costs and raise property prices.


Types of floods

Malaysian Institute of Planners president Ihsan Zainal Moktar says there are two categories of floods. The first being seasonal floods brought about by large amounts of precipitation.

However, flash floods can occur during periods of normal rainfall due to factors such as obstructions in the drainage channels.

Floods can be either seasonal or flash floods caused by excess surface runoff, says Ihsan

He says development in urban and suburban areas has led to increased surface runoff – excess flowing water from storms and other sources – due to water-impermeable materials and surfaces used in construction and infrastructure, such as tarmac.

New townships can be sustainably planned to minimise rampant urbanisation and suburbanisation while encouraging the use of water-permeable materials.

Ihsan says: “In terms of mitigating flood concerns in existing cities and townships, multi-usage can be applied to spaces such as football fields, parks and carparks.

“Under normal circumstances, they would be used for recreational purposes, events and so on. But during heavy rainfall, these spaces can function as retention ponds.

“This has already been implemented in Copenhagen, Denmark, and has been piloted in Malaysia in Precinct 12, Putrajaya.”

‘Sponge’ buildings can be used to mitigate flood concerns in urban areas, says Alif

Veritas Design Group associate architect Alif Arif says garbage-clogged drains, high tides, insufficient outlets leading to retention ponds, small culverts and shallow streams unable to cope with a large volume of water contribute to floods.

“One of the easiest ways all of us can contribute is by not throwing our garbage or waste into the drains. Clogged drains are one of the major causes of flash floods as it reduces drainage capacity.

“Another is to focus on recycling our waste as it is environmentally friendly and at the same time prevents drains clogging,” he says.

Other ways to reduce flash floods include controlling surface runoffs at the source, minimising or regulating hillslope developments more strictly to prevent soil erosions and surface runoffs and increasing the drainage capacity.

Drainage capacity should also be designed in compliance with the MSMA.


Community investment

Real Estate and Housing Developers’ Association Malaysia immediate past president Datuk Seri Michael Yam notes that guidelines regulating open spaces have been in place for some time.

“As far back as I can remember, projects must include a minimum 10% of open spaces, including greenery and retention ponds. If these rules are adhered to, they would mitigate flooding concerns,” he says.

On the part of developers, a responsible approach to the geographical context surrounding their projects can prevent flooding or even address existing issues.

Eco World Development Group Bhd’s efforts in its Eco Grandeur township in Puncak Alam, Selangor, is a case study of how far-sighted developers can add value to the communities in which they operate.

“When we venture into a new area, we elevate the standards of existing infrastructure in the vicinity, with permanent infrastructure expansion going into full swing later in the development cycle,” says Eco World Development Group Bhd divisional general manager Ho Kwee Hong.

Kwee Hong’s background in civil engineering and hydrology paid off in dividends while addressing flood-prone sites in Puncak Alam

“We also resolve local issues such as the flash floods in the vicinity of Eco Grandeur wherever we find them, as a showcase of our commitment to the community.”

Here, Ho’s background in civil engineering with a major in water resources has paid dividends.

Specialising in flood forecasting, she leveraged her experience as a hydrology engineer during initial surveys of the area surrounding the Eco Grandeur site.

Coming across reports of persistent flooding in two specific locations in the vicinity, which saw the evacuation of 144 residents from 60 homes as recently as November 2015, Ho dispatched her team to the affected sites.

There, they traced the floods to blockages in earth drains caused by maintenance issues. These were addressed through extensive dredging and drainage works, and to date, there have been no recurring reports of rising water levels in Puncak Alam following EcoWorld’s entry into the area.


Innovative concepts

Closer to the city centre, initiatives such as the Kuala Lumpur Flood Mitigation Flood project and Stormwater Management and Road Tunnel (SMART Tunnel) have prevented the recurrence of major incidents such as the 1926 and 1971 floods (see sidebar).

In the city, the best design to mitigate potential flooding is to create a “sponge” building. This is one that can detain, clean and drain water in an ecological manner, says Alif.

Compulsory building features that are being incorporated at the moment are On-Site Detention Tanks (OSD) and Rainwater Harvesting Tanks (RWH), he says.

“The OSD tanks work by detaining the rainwater for a limited time before it is released to the main drains. The tanks should remain empty, except during a period of rainfall and shortly after that.

“RWH works by capturing the rainwater in the development’s catchment area and recycling it for irrigation uses.

“Depending on the system used, the water from the RWH tanks can be used for car washing and to flush toilets.

“Both the OSD and RWH tanks mitigate potential floods by reducing the surface runoff at the buildings area,” he says.

Other approaches to creating a “sponge building” is to have more green roofs or roof gardens in the design, says Alif.

“The roofs will be covered by vegetation and absorb rainwater, while roof gardens will mitigate floods and remove nitrogen pollution from it [rainwater].

“They will also inject much-needed vegetation to the increasingly concrete jungles of Kuala Lumpur and Penang. Besides, roof gardens look great and create a very healthy living environment.

“Also, another feature is to have permeable pavements, sidewalks and gardens such as half-open pavements with grass or using Grasscrete pavements,” he says.

Ho Chin Soon Research Sdn Bhd CEO Ishmael Ho says proactive planning is necessary to address environmental disasters before they happen.

“As development moves outwards from the city, a lot more high-rises are coming up
along the mountain ranges to the east of the city, such as Bukit Ampang and particularly Wangsa Maju.

“Instead of just focusing on floods as the flavour of the month, we need to look at how the slopes can be buttressed and reinforced to address landslides before they happen, rather than responding after the fact,” Ishmael says.

Klang Valley also vulnerable to floods

WITH large-scale flooding in Penang, Kelantan and Terengganu in recent years, it’s easy to forget that Klang Valley has had its share of such disasters in the past due to its geographical profile.

Prominent among these were the major floods of 1926 and 1971, the latter of which claimed 61 lives and affected 180,000 residents in Kuala Lumpur, with an estimated economic impact of more than RM200 mil.

The Drainage and Irrigation Department (DID) reports it as the worst flood disaster in the country since the Great Flood of 1926, which affected the whole of Peninsular Malaysia.

Kuala Lumpur’s particular vulnerability to flooding is due to its location in a floodplain at the confluence of the Klang, Batu and Gombak Rivers, giving rise to its name which translates as “muddy confluence”.

This is exacerbated by seasonal variations in the El Nino Southern Oscillation, which can lead to protracted La Nina events with heavy monsoon rainfalls, according to a report published last year – The ‘Great Flood’ of 1926: environmental change and post-disaster management in British Malaya.

Sabah and Sarawak have seen major floods as well, such as the 1996 devastation caused by Tropical Storm Greg in Keningau.

The storm caused four rivers in the district capital to swell their banks, with more than 241 lives lost, 4,000 homes destroyed and an estimated US$97.8 mil (RM413.55 mil) in damages.

The impact of the 1971 floods led to positive changes, with the implementation of the DID’s RM1.27 bil Kuala Lumpur Flood Mitigation Project.

This project saw the raising of the Klang Gates gravity arch concrete dam by three metres in 1980, increasing its total capacity to 28.8 million cubic metres.

Other measures included the widening and deepening of 47.2km of river channels, and the construction of the RM20 mil Batu Dam and Reservoir, as well as the Batu Retention Pond and Gombak River Diversion. 


Floods can damage both the physical structure and contents of buildings, but only the former is commonly insured

Better safe than sorry

MALAYSIANS are used to the fact that floods are normal occurrences, especially during the monsoon season. But, many are still taken by surprise when a major one occurs.

Despite this, many remain uninsured, even those who are residing in flood-prone areas, according to Allianz General Insurance Company (Malaysia) Bhd.

“There is still a lack of awareness on buying insurance to protect vehicles and or properties against flooding as most adopt a wait-and-see attitude.

“They rather pay a minimum or basic premium and are reluctant to fork out that extra amount even though they know it is wise to do so. It is too late to act when tragedy strikes,” says its head of commercial business John Yep.

He says having one’s home damaged or destroyed in a natural disaster can be devastating and losses arising from such incidents can be a huge financial burden.

There are two basic types of policies pertaining to floods. “Flood is an insured peril under house owner insurance, which is the most common home insurance available to individuals to protect the physical building,” says Yep.

The other – a householder plan – covers house contents like household goods, personal effects and other moveable possessions, he says.

The second kind of policy is designed for tenants and renters who would be more concerned about the contents of their home rather than the house itself. The amount covered depends on the type of coverage chosen by the insured.

“Companies are more aware of flood exposure, but their issue is more to ensure adequacy and avoid being underinsured,” he says.

Unfortunately, there is no direct flood insurance for cars. The comprehensive car insurance does not protect the vehicle against damage caused by flooding.

Instead, most are bundled under a top-up package which will offer a small sum towards damage by floods. This comes under compassionate flood coverage, in many cases, amounting to RM1,500 only.

This article first appeared in Focus Malaysia Issue 259.