Below are some of the issues that exacerbate the sewerage capacity issue London faces when it rains. Why is Thames Water much less keen on addressing these than on constructing the big concrete pipe under the river that is the Thames Tideway Tunnel?
Water mains leakage
London has one of leakiest water mains network in the industrialized world, meaning a staggering 26% of the drinking water sent down Thames Water’s pipes never reaches its destination; enough to fill Wembley Stadium every three days. In the 20 years since privatization of the industry, TW’s leakage rate has improved by a pathetic 3.41% (see graph alongside).
Why does this matter?
Beside the sheer waste, by a conservative estimate, 40% of all this leaked water finds its way into combined sewers, seriously compounding their wet weather capacity issue and contributing to their overflows into the Thames.
To put this in perspective, the volume of leaked drinkable water is about 6 times the volume of sewer overflows that the Thames Tunnel is allegedly required to tackle…
Under the Thames Tunnel proposal, this clear water will continue to gush down the sewers, mixing with sewage and causing occasional overflows, to be channelled by the Tunnel to sewage treatment works to be cleansed. Needless to say, the carbon footprint of this preposterous exercise is also substantial…
Could we do better?
In the 21st century, is it really impossible, as Thames Water claim, to do better? You will have heard TW complain that their “Victorian” network of pipes makes improvements very challenging. Well, Paris, an equally old and comparably large City manages a leakage rate of under 10%… Where there’s a will…
London needs to cut Thames Water’s obscene leakage rates. The company currently loses 30% of the water it puts into the mains – 200 litres a day for every customer. Paris and New York only lose around 10%; Singapore is below 5%.
Fred Pearce, New Scientist’s Environment Consultant, The Guardian 24 Feb 2012
Southern Water’s rollout of water meters confirms that they reduce consumption by an average of 10-20%. In times of water scarcity, this could be a substantial help.
Water is one of mankind’s most precious resources; any incentive to prevent its waste, in a world where 780m people lack access to clean water, is simply right. The reduced consumption would obviously also help with the wet weather combined sewerage capacity issue.
Can it be done?
Fairness on Tap is a coalition of environmental organizations which defines three practical steps to get at least 80% of England on metering by 2020. After a very successful pilot project in the Isle of Wight in the 1990′s, which reduced consumption by 18%, Southern Water is now rolling out meters throughout its customer base in a 5 years period (2010-2015). In London, persistent industry lobbying – sounds familiar? – ensures very little progress is made.
What about vulnerable customers?
The major issue with metering is the need to protect vulnerable consumers, such as large families on low income. There are reasonably simple solutions to this, as suggested by “Fairness on Tap”, which would still ensure that everyone has an incentive to save water.
Water affordability is becoming a real issue for some customers. Since privatisation in 1989, bills have increased by more than 40% in real terms
Large numbers of the poorest customers could reduce their affordability risks if they switched to metered charges.
Ofwat, “affordability for all”, 2011
Are there ways for consumers to save waters?
This question has the same answer as the same question in the context of energy efficiency: a resounding yes. For example, it’s a little known fact that toilets are by far the biggest use of water in the home. Just like Green Infrastructure is eminently feasible where there’s a will, the same goes for saving water in the home. For example, Interflush is a company which proposes a simple device that can save 18-40% domestic water by being retrofitted in existing toilets.
Why Thames Water isn’t interested
It’s pretty simple – fixing leaks costs money. Also, under the unmetered system, we get to pay for the leaked water. Water metering, as explained above, would reduce consumption; which, again, would reduce Thames Water’s revenue…