The last drop

We may have to curtail our liberal use of water

Like any obliging husband, Ken Proctor watered the garden when his wife asked him to. It was nothing fancy: the Proctors had a small lawn and a few rose bushes outside the front of their suburban home just south of Sydney. In the midst of a seven-year drought in Australia, they certainly needed watering, but Proctor was careful to get the hose out only when the authorities allowed – either Wednesday or Sunday, before 10am or after 4pm.

His wife reminded him about the roses at around 5.30pm on Wednesday 31 October 2007, so he was perfectly within the law. A neighbour, however, disagreed. Todd Munter challenged Proctor over the water restrictions, they argued and when Proctor turned the hose on him, they got into a fight. Proctor was pushed to the floor and struck on the head. Passers-by pulled Munter away, but Proctor had gone into cardiac arrest and died in hospital.

Nobody expects to be killed over a few drops of water, but the Proctor murder is a warning: tensions like this could become more common in the future. Global temperatures are rising and rainfall is scarce in the placed that need it the most. The worldwide population is set to rise by more than two billion in the next 50 years and renewable sources of freshwater are running dry not just in Australia but all over the planet. As more of us scrap over the water we have, experts are warning that arid regions will only get more cracked and parched in the coming century.

“We’re using more than half of the renewable water now running through the global water cycle,” says Fred Pearce, an environment consultant and author of When the Rivers Run Dry. “The world’s underground water reserves are also being pumped out much faster than they’re being replaced by the rains. We’re using water to the limit.”

A whistle-stop tour of a dehydrated planet would seem to confirm this. In Australia, the unforgiving drought has forced 10,000 farming families from their homes, while cities like Melbourne are getting by with water storage at less than 30 per cent of their capacity. In China’s dry north, 490 million people in 100 cities face severe water shortages. Around 300,000km2 (100,000 square miles) of Mediterranean coastline is at risk of desertification as the north African climate spreads without mercy. And in Africa itself, much of the continent is already crippled by drought with a bleak forecast for the 21st century: 30 per cent less rainfall is predicted compared to last century, Lake Chad is rapidly disappearing, while semi-arid swathes of southern Africa look set to become drier still.

Drying out

Even parts of the United States are gasping for water. A drought in the southwest of the country has lasted the better part of a decade, as conditions return to the savage Dust Bowl of the 1930s. Between 2002 and 2005 alone, more than 45 million pine trees died in New Mexico as a result of the water shortage and baking temperatures. And by 2021, researchers have warned that reservoirs on the Colorado River – which supply between 20 and 30 million people – could run dry.

The really bad news is that these conditions look set to become the norm for this century. Last year, climatologists at Columbia University in New York analysed the predictions of 19 climate models and found that while wet regions look set to get wetter, changing sea temperatures and air flows would cause the expansion of arid sub-tropical regions like the southwest US.

“Pretty much every climate model out there predicts that those parts of the world are going to become increasingly dry in this century,” says Richard Seager, who led the research. “You’ll still see sequences of wet years, but they’ll all be occurring around a mean climate that is getting drier. That’s going to be a problem.”

As well as the obvious local challenges that this will bring, especially in agriculture (which accounts for 70 per cent of the world’s water use), the lack of water could also cause problems on an international scale. Where rivers flow from one country into another, tension over a diminishing shared supply is likely to intensify existing regional quarrels.

Some claim that the world witnessed a water over war as far back as 1967. Others disagree, but the Six Day War between Israel and its Arab neighbours did result in tighter Israeli control of the River Jordan. And more recently, Israel’s former water commissioner Meir Ben Meir warned that further water wars between the likes of Israel, Palestine, Jordan and Syria are a real threat in the 21st century.

“You’ll only tend to get water wars if there are other exacerbating factors, but there are plenty of those in the Middle East,” says Pearce. “Egypt has also said that if there’s a war in its part of the world, it’s likely to be about water. Egypt is so dependent on flows coming down the River Nile that if upstream countries like Ethiopia start extracting water in large amounts, then they might simply go to war in order to stop them.”

But if the threat of water wars are so real, then why haven’t we seen more water related violence over the past 50 years? The answer, according to water policy advisor Professor Tony Allan, is ‘virtual water’.

“This is a concept which I coined because I was trying to explain the absence of armed conflict in the Middle East,” says Allan, who holds posts at both Kings College London and the School of Oriental and African Studies. “There are 300 million people in the Middle East, but they’ve only got enough water for about half that number.”

Food flood

The reason these figures don’t add up to armed conflict lies in imported food. Allan spotted that by importing food, countries not only feed their hunger but also remove the requirement for water to grow that food. After all, we may drink around a cubic metre of water every year, and use a further 100 cubic metres to wash – but we each need around 1000 cubic metres of water to feed ourselves.

“Every tonne of grain takes a thousand tonnes of water to grow,” he says. “But if you import that grain, you ease the economic, and more important, the political, stress of finding water that isn’t there. The great virtue of this virtual water – the water embedded in food – is that the process is invisible. It’s economically invisible and politically silent. You can essentially solve a serious problem without voters knowing about it.”

This convenient solution explains how we get by in the UK. Sure, we get our share of rain, but wash-out summers like that of 2007 belie the fact that some parts of the country simply don’t have enough water. The Thames Basin is home to approximately 17.5 million people, yet there’s only enough water there for 1.5 million. For now, the deficit is plugged by the virtual water embedded in the food we import.

As the world continues to dry, however, water itself may become a commodity that is imported and exported between nations. Cyprus, Jordan and Singapore already rely overwhelmingly on foreign supplies. And earlier this year, around a dozen container ships, each filled with 28 million litres of water, made their way along the Catalan coast as Spain was forced to import water from France when Barcelona’s supplies evaporated to 15 per cent capacity.

“I think we are going to see more of that in this century,” says Trevor Bishop, head of water resource management at the Environment Agency. “People describe water as the next oil. I think they’re exaggerating a bit, but it is likely that the economics of water will become a decisive factor in relationships between countries.”

Water palaver!

In the meantime, the world is experimenting with different methods to fix its water problem. China has turned to engineering on the largest scale imaginable. The South-North Water Transfer Project will effectively re-plumb the entire country by 2050, as a massive network of pipes, reservoirs and pumping stations carry 50 cubic kilometres of water to the dry north of the country every year (at the same time the north is ‘sending’ virtual water to the south. Like the Three Gorges Dam, however, the project is heavily criticised for its environmental cost and because millions of people will be displaced.

Australia sees the situation as more a problem of demand than supply. It has enjoyed some success in lowering public consumption of water through metering and tariffs that charge more for water use at peak times. According to Bishop and the Environment Agency, which will publish its water strategy for the next 50 years at the end of this year, lowering demand is key for the UK as an unpredictable future looms.

“The problem with climate change is that it’s all about planning for uncertainty and you don’t know how things will pan out,” he says. “In the future, we might see droughts like those in Barcelona or Australia. That would be different from anything we’ve experienced before. We have to manage demands for water downwards so that we’ve got a lower reliance on the natural environment.”

Ian Taylor is deputy editor of Focus

Is desalination the key?

In May of this year, London mayor Boris Johnson removed a legal challenge for Thames Water to build a desalination plant that will treat saltwater from the Thames estuary and make it drinkable. Thames Water claim the £200 million plant will provide 140 million litres of water every day – enough to supply 400,000 homes in.

Desalination is used globally, but it remains a controversial, energy-intensive solution. Former mayor Ken Livingstone had challenged the Thames Gateway project on environmental grounds, while others say that the company should not spend so much money on a short-term solution when pipes need fixing.

“If you allow it in too soon, people become dependent on it,” says water policy expert Professor Tony Allan. “Getting yourself locked in to depending on desalination, stops you looking for economies and sensible behaviours in the system as a whole. Israel and Barcelona are examples making this mistake. We should first help people learne how to control their consumption.”

In spite of these concerns, the project has the backing of the Environment Agency, which described it as ‘regrettably necessary’ after Thames Water first submitted a planning application in 2004. An extra 800,000 residents are expected to move to London by 2016 and since 1980, the average person’s daily water use has gone up by 23 litres in the area.

“Thames Water has a deficit in its supply and demand balance and the desalination plant can be built very quickly,” says Trevor Bishop, head of water resource management at the Environment Agency. “To make sure they are in surplus in the short-term, the plant was the right thing to do.”

The plant will be completed by the end of 2009, and Thames Water says it will be powered by renewable energy. Even so, more are not set to follow. “We’d never say never for individual sites where it’s right for supply, cost and the environment, but we’re not in favour of large-scale desalination around the country.”

A Thirst for Technology

How to fix the water problem

Drip irrigation

It’s an ancient idea, but drip irrigation – which uses a system of valves, pipes and meters to deliver a precise amount of water to a crop’s roots – is not as widely used as you might think. Flood irrigation, which is far less efficient, is still more widely used worldwide.

Water Transfer

Large-scale engineering projects can divert water from rivers in wet regions of a country to the most arid. China’s planned South-North Water Transfer Project will involve a massive network of dams, pipes and pumping stations, but critics say the environmental costs are huge.

GM crops

During dry spells, plants lose up to 95 per cent of their water as vapour through pores on their leaves. But this year scientists discovered the gene that controls this process, so future crops with genetically modified pores could survive the most severe droughts by cutting down on transpiration.

Dual plumbing systems

It’ll be effectively impossible to replace the whole of the UK’s Victorian plumbing system, but in new towns and cities dual plumbing systems could deliver fresh water to the taps specifically for drinking, while ‘greywater’ is supplied to the toilet, garden and washing machines.

Water metering

Intelligent water meters will soon become more common in homes all over the UK. Placed in plain sight on the wall rather than tucked under the sink or outside the house, they will allow families to monitor and manage their water usage more efficiently.

Rainwater harvesting

It’s hardly a cutting edge solution, but the average roof captures 80,000 litres of rainfall every year. Simple water butts can collect enough to water the garden with, while more complex systems can be put in place that will pump it to toilets and washing machines around the house.

Find out more

• When the Rivers Run Dry, Fred Pearce (Eden Project Books, 2006)
• Lots of information from the UK’s water regulator, Ofwat www.ofwat.gov.uk
• A global water perspective from the UN www.unwater.org