The Big Issue: The great leak

[dc]In February 2017, Cape Town’s dams were at 36% of their total capacity, down by nearly 7% from this time last year. When The Big Issue went to print on 17 March 2017, Cape Town’s dam levels were at an alarming 30%. By the time you read this article, the city may very well have less than 100 days’ water supply left. If the water level falls below 10% it can no longer be pumped out. It will take nothing short of a miracle to overturn this dire situation.[/dc]

Down the drain

In recent months, the water crisis has been defined by tougher water restrictions and naming-and-shaming tactics by the City of Cape Town. All the stops are being pulled out by local government and residents alike to conserve water. But what about the immeasurable quantity of water being lost through pipe bursts and leaks?

The city services a pipe network of close to 11 000km (the equivalent distance from here to Australia), connecting 650 000 households.

Councillor Xanthea Limberg (Cape Town’s mayoral committee member for informal settlements, water and water services and energy) says, on average, the city deals with more than 500 water-related callouts per week. But not all of these are leaks and bursts.

Xanthea says it’s not possible to measure the amount or rand value of water wasted when a water pipe bursts. “A large burst can let more water go to waste in a few seconds than a slow leak in a few weeks,” she explains.

However, let’s use the Crawford house named among the top five alleged water users in Cape Town as an example. The owner was billed R119 000 for 702 000 litres of water, as a result of a burst underground pipe.

If at least half of the city’s 2 000 water-related callouts are as a result of burst pipes or leakages, one can only imagine the amount and cost of the water wasted.

The buck stops with you

Who is responsible to repair water leaks and burst pipes? Cape Town’s regulations are clear: “If a leak is within the boundaries of a private property, it is the responsibility of the private property owner. If it is outside the boundaries of a private property, the city will repair the leak or burst pipe,” says Xanthea.

It is therefore in property owners’ interest to proactively check for and fix leaks, even if they stem from underground pipes. Read your water meter regularly and monitor your water bill. Notify the city immediately if you notice unusually high consumption. Also check taps, drip irrigation systems, shower heads and swimming pools for leaks.

Water losses

The World Wildlife Fund South Africa’s (WWF-SA) 2016 report titled Water: Facts and Futures… Rethinking South Africa’s Water Future provides valuable insight into our water crisis, leakages and how to address water loss. The report states that 37% of water in our urban piped water systems leaks out or is used illegally. This is fairly typical of leakage losses worldwide, especially from ageing infrastructure.

“As a water-scarce country, we urgently need to bring down the 37% losses that occur in most South African municipalities,” says Christine Colvin, Freshwater senior manager at WWF-SA.

“If we could reduce this loss to those of a world leader like Denmark (5% leakages), we would be able to close the gap between supply and demand without expensive investment in new infrastructure,” she says, adding: “South Africa needs to make use of leading leakage detection technology on pressurised systems, which can rapidly alert operators to leaks and breakages, and detect leaks in old, low-pressure reticulation systems.”

Remedial action

Xanthea explains while ageing infrastructure is a contributing factor, it is not the only reason for pipe bursts.

“Older pipes are not necessarily more likely to burst. Pipe bursts are also caused by movement of the ground and pressure fluctuations. It is normally a combination of the three which causes a pipe to burst,” she says.

So, what is the city doing to prevent water wastage through burst pipes? Xanthea says Cape Town has implemented a water demand management plan, which includes pressure management (a valve is installed to regulate pressure during low consumption times, which reduces wear and tear on the pipes) and a pipe replacement programme that prioritises capital expenditure based on burst history.

This programme has reduced the burst rate from 63.9 bursts per 100km of piping in the 2010/2011 financial year to 31 bursts per 100km, saving millions of litres of water.

The city is currently trialling a unique software tool, the Comparative Flow Pattern Distribution Method, which analyses water-consumption data. It serves as an early detection tool for pipe leaks and bursts, which could result in millions of rands worth of savings. This technology has helped the Netherlands bring down its water losses to one of the world’s best levels, at 10.2%.

“We are still some way away from full implementation of this tool, so we call on residents to report leaks,” says Xanthea.