Dr Kala Vairavamoorthy on Efficient Water Usage, Urban Planning to Mitigate Climate Change

by Jeremy Torr in Singapore

26 December 2008. “The problem in many Asian cities is not that they don’t have water, but that the supplies are very erratic,” says Dr Kala Vairavamoorthy from the University of Birmingham, UK. Kala was in Singapore recently to give one of the regular Distinguished Visitors Lectures sponsored by the British High Commissioner. His talk addressed an issue that is becoming almost as frequent a headline as oil prices or CO2 emissions.

In most cases, argues Kala, who holds the Chair in Water Engineering at his university and heads the SWITCH project researching water planning worldwide in conjunction with UNESCO, the problem is simply down to inefficient usage. Cities such as Colombo in Sri Lanka and Delhi lose as much as 50% of their original water supplies.

“Most of the water systems in the major cities work OK right now, so people don’t want to change even though they know there are impending problems. But if we take a realistic look at the way our cities are developing, it’s easy to see that the systems are completely unsustainable,” he says. “It’s a time bomb.”

But if the water supply systems in cities around the globe are reason for concern, then the sewage systems should have us collectively running for the city exits. According to Kala’s figures, up to 85% of all sewage water – both city and rural - is untreated, and is allowed to simply run off to nobody knows where. Compound these facts with the indisputable effects of climate change - major floods, droughts leading to low water flows and sewage stagnation - and the recipe for what Kala calls extreme events is almost fully baked and ready to serve.

“The problems we see already, like cracking water pipes and sewers through old age and lack of maintenance, will get worse,” he says. “The fact that we are having greater temperature swings than before speeds up the deterioration of the physical infrastructure.”

“One of the biggest issues we see in sustainable water management is in asset management, not the supply of water itself,” says Kala.

But it’s not all doom and gloom. One of the chinks of light that Kala sees is that the majority of urban growth in the next few years will be in smaller and less developed cities – not in megacities like London, Mumbai, or Tokyo. “This,” he says, “gives us the opportunity to start to manage (water) sensibly.”

That means more than an upgrade of our metropolitan water supply and sewage facilities. It means integrated planning. In some studies he and his team have done in Brazil, they noted that local flooding had increased due to a dramatic increase in paving, that temperatures had risen due to significantly reduced transpiration from natural or vegetation-covered surfaces, and that an ‘urban microclimate’ had been established that was much less comfortable than the natural state.

Because these are happening in still-developing urban areas, it gives us the opportunity to manage sensibly when it comes to water usage, he says. “And we have to accept that we will have to do it.Many city planners already know they have problems but are too scared to make any major changes.”

The changes he advocates are not major engineering works and hi-tech gadget-driven solutions; they are much simpler than that. They are changes to communication.

“We need to get all the people involved to sit down together and talk about what they are doing. We need to get the flood engineers talking to the drainage planners, and the drainage guys talking to the urban planning guys. At the moment there is a universal lack of integrated planning; it’s very fragmented. We need to help all the interested parties get together to create Learning Alliances so they can all participate in a more flexible design approach,” he asserts.

Kala’s flexible design approach ranges across everything from green roofs, sustainable drainage, re-configurable water supplies and effective re-use of water supplies downstream of the primary use. In concert, not as discrete, unrelated efforts.

“We can look at using rivers to help clean water with bank filtration, wetlands to help remove pollutants, and conventional water treatment plants to back those up,” he says.

“But the key issue is not technical – it is an attitude issue. We have to get planners working together and harmonised in what they are doing. A good example is Singapore; here there is 100% access to good water, and a mere 4-5% wastage.” London’s Thames Water, in comparison, wastes a staggering 34% of its water supplies. “They know they have problems and they have regular pipe breaks – but they are scared of change. They need to invest time in getting the right inputs (from people), in where they are using their energy, and in planning,” says Kala.

And time is against us, so Kala’s SWITCH team is working fast. “Last year was the first time ever where there were more people living in urban areas than in rural areas. This will only increase, and we have to plan for that, even though we don’t know exactly what to plan for,” he admits.

The solution, he says, is to plan for flexibility. “In Australia they are taking radical measures already because their backs are to the wall and they have no choice,” he says. “We should be doing the same.”

What can I do?

  • ·Reuse all washing up water to clean the car, flush the toilet
  • ·Put a brick in the toilet cistern to use less water per flush
  • ·Fit low-flow shower heads
  • ·Make sure all taps are turned off and don’t drip; fit a thimble to control surge
  • ·Never use running water to wash anything
  • ·Reuse water used to wash vegetables to water the plants with
  • ·Save laundry and washing up for a really big load at one go
  • ·Don’t put solids down the toilet

Contact Dr Kala Vairavamoorthy at k.vairavamoorthy@bham.ac.uk.