Tapping free flows

Cisterns need not be big, black and ugly, as this American homeowner shows. -- MCT

Harnessing the rain is now mandatory for new homes in some states.

WHEN it pours, out come the pails. On roofs, rainwater gushes down into gutters and pipes that flow into storage tanks. And mothers order their kids to go bathe in the rain. Such scenes were the norm in Malaysia 40 years ago. Of course, everyone was frugal then and it made complete sense to harness water that is perfectly usable, and free.

How odd that now, we need to have a law to make rainwater recycling compulsory. An amendment to the Uniform Building By-Laws 1984 requires newly built detached buildings as well as bungalows and semi-detached bungalows with a roof area of 100sqm and above, to be equipped with a system that captures rainwater for reuse.

So the next time you see an advertisement for a housing project that touts that the homes come with a rainwater harvesting system, don’t think that the developer is being generous or green.

They have to do this under the law. And if they do not, well, they are breaking it.

The legal requirement was finally introduced last year after years of feasibility studies and talks (the housing industry had protested when the ruling was mooted in the early 2000s), and makes Malaysia one of the few countries in the world to legislate rainwater harvesting.

Most countries need only offer incentives to encourage the practice. Germany, for instance, uses a carrot and stick approach: it rewards those who tap rainwater and penalises those who allow runoffs to enter sewerage systems. In countries where water tariffs are high, consumers need little nudging to reuse rainwater. In fact, in such countries it makes sense to collect rainwater for non-potable uses.

In Malaysia, however, the low water tariff means that the precious resource is often squandered. The most wasteful practice here is using water that is good enough to drink to flush the toilet, wash the car, water the garden, and for general cleaning.

The law on rainwater harvesting is meant to curb such wastage. Tapping rainwater not only reduces your monthly water bills but also lessens the demand and dependency on the public water supply and, ultimately, the need to expand water supply infrastructure. Equally important is that holding back rainwater will reduce land erosion and flooding caused by rapid runoffs whenever it pours.

The states of Johor, Kelantan, Malacca, Perak, and Selangor gazetted the Uniform Building (Amendment) By-Laws 2012 early last year, paving the way for mandatory rainwater harvesting in new buildings.

The Federal Territory of Kuala Lumpur is not governed by the legislation but frequent flash floods have prompted it to become an early adopter of the green system – City Hall made it mandatory for all residential houses in 2008 and commercial buildings in 2010. Between 2010 and 2012, rainwater harvesting systems were installed in 1,050 terrace houses, 483 bungalows and semi-detached bungalows, and 148 commercial buildings and schemes in the capital.

“All development must comply with the condition to install rainwater harvesting systems within their development before the certificate of completion compliance is issued,” says Sabudin Mohd Salleh, deputy director at the infrastructure planning department in City Hall. “City Hall has not carried out a survey on the benefits of the system but as long as you hold back rainwater, you’re helping to reduce flooding downstream.”

Also taking a bold green step is the Petaling Jaya City Council, which enforced the rule for all new buildings in 2010. The growing interest in green buildings – plus the marketing edge it gives them – saw some developers offering rainwater capturing systems in their projects even before the onset of the regulation. Examples include the Mah Sing Group (in its Garden Residence project in Cyberjaya) and Sime Darby Property (in USJ Heights, Subang Jaya).

Still, there are other developers that are ignoring this legal requirement. In one recently launched project in Puchong, Selangor, under the Sepang Municipal Council, the semi-detached home priced at over RM1.3mil does not come with a rainwater harvesting system.

Generally, however, there has been higher acceptance of the ruling in urban areas, according to Dr Chee Chung Yee, technical director of Bacfree, a provider of rainwater harvesting systems.

“We are finally seeing a big jump in inquiries and orders. We have installed the system at 3,500 residences and 20 commercial buildings, mostly in the Klang Valley, over the past two years.”

It is a different story on the outskirts, where there is still resistance from both developers and local authorities. “There is a lack of interest from small- and medium-scale developers because of a lack of knowledge and awareness as well as cost constraints,” says Dr Chee.

Having to deal with various local authorities, he notes a difference in the pace of enforcement of the new ruling. “Some councils are not ready to implement it. They have no idea how to do it, so they take a slower pace. Some councils still allow exemptions from the ruling. This is for practical reasons because in some semi-rural areas, house prices are low (for instance, a bungalow costing below RM500,000), so it would be difficult for developers to incorporate rainwater harvesting systems.”

He says the price of the system ranges from RM1,500 to RM10,000, depending on the intended usage. For irrigating the garden, one needs only a simple system. For use in the toilet, the system requires extra filtration and piping. He often gets asked about the return of investment but that, he reckons, should not be a consideration since it can take as long as 20 to 30 years before users see savings because of Malaysia’s low water tariff.

City Hall’s Sabudin readily agrees. “Developers should not talk about return of investment. Water is cheap, it’s negligible. Water is not the cost but flooding is.”

He says City Hall has received complaints about the extra expenses of installing rainwater harvesting systems. An analysis shows that they cost between RM12,000 and RM25,000 for semi-detached and detached bungalows, and between RM100,000 and RM500,000 for a multi-storey building or mixed development – “This works out to only about 1% of the total cost of construction of the house or building,” Sabudin points out.

He adds that City Hall does receive appeals from consultants, house owners and developers for exemptions but so far, all such requests have been rejected.

These are early days yet for the ruling and teething problems persist. Complicating matters is the vagueness of the law and insufficient system specifications.

“There is a lack of common standards and guidelines on design, materials, pumps, filtration systems, storage systems, tank sizing, maintenance schedule, and water quality,” says Dr Chee.

“A specification on water quality is important because bacteria will grow in rainwater. If the water is aerosolised for the garden, you might be spreading bacteria-contaminated water. For such uses, we usually suggest adding a filter and disinfectant in the system to prevent bacterial growth.”

The placement of the water storage tank is equally important and is among the many factors that need to be considered to ensure successful rainwater harvesting, lest one ends up like the Selangor State Development Corporation (PKNS) project in Kota Damansara, Selangor. In the 2009 scheme, rainwater harvesting systems were installed in linkhouses. However, the storage tank was placed in the backyard, which not only took up space but was an eyesore. A survey showed that up to 60% of the tanks were subsequently removed.

“You have to work with the architect and developer to identify a suitable location for the water storage tank. Usually, this is on the air-conditioner ledge, inside the roof or on a flat roof. It has to be aesthetically acceptable and accessible for maintenance,” asserts Dr Chee.

He advocates cleaning the system every four to five months to remove trapped material. He also prefers to install tanks above the ground so gravity will channel the water down. “This is a green project, so it makes sense to have a green system rather than use electricity to pump the water.”

Also, he says town planners and council enforcement officers must be trained on the legal requirements and accepted designs for rainwater harvesting systems, and the Housing and Local Government Ministry has to take the lead here at a federal level.

The ruling’s minimum roof size of 10sqm essentially excludes linkhouses but that has not stopped some developers from providing rainwater collection systems for such homes. Sime Darby made the provision for its linkhouses in Bukit Raja, Klang; and Ken Holdings for its homes in Ken Rimba, Shah Alam.

Dr Chee, however, does not support the idea of imposing the ruling on linkhouses at this point as it will be a burden to small developers. Also, “Linkhouses have only a small roof area, and the effectiveness of small systems is questionable. It is pointless to go through so much effort to collect so little.”

There are also design constraints in terms of available space for tanks and downpipes. Dr Chee explains that as linkhouses usually have pitched roofs at the front and back, it would be difficult to combine flows from both areas into a single collection system; and two systems would be unwieldy.

City Hall got around this hurdle by giving some leeway: it allows rainwater to be captured from just half of the roof area of a linkhouse.

“The guidelines are still evolving. They were drawn up by various experts looking at different aspects. Some see it from the green perspective, others from the city planning and drainage side, so they fail to see the problems that we have on the ground,” says Dr Chee.

Nevertheless, he is glad that at least there is now a legal document on rainwater harvesting in place to encourage the green habit of using rainwater.

Related story:

Recycling rainwater

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