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Where's the water? | Tackling scarcity

california water supply

The world runs on water. Clean, reliable water supplies are vital for industry, agriculture, and energy production. Every community and ecosystem on Earth depends on water for sanitation, hygiene, and daily survival.

Yet the world’s water systems face formidable threats. According to the United Nations, more than 1bn people currently live in water-scarce regions, and according to the World Bank, as many as 3.5bn people could experience water scarcity by 2025.

Increasing pressure on freshwater resources is exacerbated by the effects of climate change. The rate of groundwater withdrawals has increased by 1% per year since the 1980s. Between 2011 and 2050,  the global population is expected to increase by 33%, from 7bn to 9bn, while food demand will rise by 70% in the same period.

global rainfall

global rainfall

Furthermore, the fifth assessment report of the Intergovernmental Panel on Climate Change forecasts that for each degree of global warming, around 7% of the global population will face an almost 20% decrease in renewable water resources.

And the situation could already be worse than we think.

That is because previous global water scarcity assessments, measuring water scarcity annually, may have underestimated water scarcity experienced by consumers as it fails to capture the seasonal fluctuations in water consumption and availability.

At least two-thirds of the global population, over 4bn people, live with severe water scarcity for at least one month every year, according to a major new analysis by the University of Twente in the Netherlands.

The new research also reveals that 500M people live in places where water consumption is double the amount replenished by rain for the entire year, leaving them extremely vulnerable as underground aquifers run down.

Many of those living with fragile water resources are in India and China, but other regions highlighted are the central and western United States, Australia and even the London.

The analysis, published in the journal Science Advances in February, claims to be the first to examine global water scarcity by month – most other studies have looked at a quarterly or annual time period. It also claims to be the first study to have examined the problem in so much detail – it has broken land areas up into 50km2 chunks.

global water demand

global water demand

“The results imply the global water situation is much worse than suggested by previous studies, which estimated such scarcity impacts between 1.7bn and 3.1bn people,” the research concludes.

But many a water engineer will tell you that the water scarcity argument has been overplayed.

One such is Mott MacDonald global head of water and environment Mark Enzer.

“There is no water scarcity,” he says. “Look at the world – there is plenty of water. It’s just it’s either full of salt or in the wrong place.”

How scarce is water?

The facts bear this out. Earth is not called the blue planet without reason; 70% of it is covered in water. It’s just that 97.5% of it is salt water. And of the 2.5% that is freshwater, 69% is frozen, 30% is underground and less that 1% is in rivers and lakes.

So maybe freshwater is not the answer.

Because increasingly when we talk water scarcity, we are talking large conurbations. There, the water is there, it is just wastewater. “Water scarcity, particularly in major urban areas, means that over the coming years humanity is going to have to get used to reuse,” says Enzer.

And that does not necessarily mean we all have to start drinking wastewater, or at least not yet.

The big issue facing humankind in relation to water is the combination of water, energy and food security

Mark Enzer,  Mott MacDonald

“There is a public mind-set issue when it comes to using reclaimed water,” notes Black & Veatch consulting director Mat Fairfax. His company has been researching this issue and recently produced a white paper highlighting ways the issue can be overcome.

We are probably not quite there yet in the need,” says Fairfax. “But if consumption continues to grow we will have to look at it,” he adds.

Right now most focus is on switching industrial and agricultural users to reuse. There is a massive win here.

 “The big issue facing humankind in relation to water is the combination of water, energy and food security,” explains Enzer. This is increasingly being called the nexus, or the meeting point, because the issues are so interlinked. With the global population growing at a rate of approximately 80M people a year, by 2030 it is estimated that the world will need 40% more water (that according to the 2030 Global Water Resources Group report), 36% more energy (that according to the BP Energy Outlook 2030); and 50% more food (that according to the UN).

Agriculture’s thirst

As an example, agriculture uses 70% of the world’s fresh water – it takes an amazing 15,000l of water to produce just 1kg of grain-fed beef, with almost all of that used to irrigate the crops fed to the cattle.

That water is also in demand by industry and the energy sector.

And switching those users to reused water takes a lot of pressure off conventional drinking water supplies.

It is a move that is happening in many places worldwide; Fairfax cites land-constrained Singapore and Hong Kong and drought-prone Queensland, Australia – all places where Black & Veatch has helped the authorities install reuse treatment facilities to supply industrial users and take pressure off conventional drinking water supplies. In Hong Kong the environment minister even drank of glass of reused water in a publicity stunt to mark the opening of its new plant in Tai Po.

India’s water reuse policy

India is probably most interesting; there it is a legal requirement that industrial users source water from a reuse plant, no more than 80km from the site to minimise pumping costs.

“So you can take the pressure off by reusing water for industrial and agricultural users, and if you build treatment near to the demand you can lower the cost of distribution,” says Fairfax.

“Most of the costs for supply are in the pumping so the more targeted you can be the better.

Opportunities for this kind of approach are limited in the UK given the challenge of separating supply lines for industrial and domestic users. But there could be opportunities, insists Fairfax: “Look at the energy sector – we’ve got six new nuclear power stations coming on stream – they’re exactly the sort of places for reclaimed water as they have such a high water use.”

Back to fresh water, and boosting storage is clearly an option. But it is a sensitive issue. “Clearly there is a huge environmental impact in building a dam,” says Fairfax. “It is many, many years now since we built new storage capacity in the UK.”

Next water resource management plans

That said, it is now something being seriously looked at by UK water companies as they prepare their next set of Water Resource Management Plans – documents produced every five years as part of the regulatory Asset Management Programme negotiations. This time the regulator has asked them to look 50 years hence and to propose strategic solutions that are not necessarily the cheapest in the short term.

So major infrastructure is on the agenda – in the UK and abroad.

One such example is the Marina Barrage, a dam built across the 350m wide Marina Channel in Singapore to keep out seawater, while forming the state’s first reservoir in the city.

The barrage is also part of a comprehensive flood control scheme to alleviate flooding in the low-lying areas in the city. During heavy rain, the series of nine crest gates at the dam will be activated to release excess storm water into the sea at low tide. At high tide, giant pumps capable of pumping the contents of an Olympic-size swimming pool per minute will drain excess storm water into the sea.

Thames catchment

It is a concept that has legs closer to home. Black & Veatch is in the midst of a big study with the Environment Agency to look at storage capacity in the Thames catchment. “The initial concept is to use it to reduce flooding, and a lot of it is upstream, but the interesting thing is looking at taking a route overground or underground and provide capacity doing that,” says Fairfax. “Underground storage is one of the few solutions you’ve got in and around London for raw water.”

And desalination is now on the agenda worldwide in a big way – whether it is in drought-stricken California (see box), densely populated Hong Kong and Singapore or water-shy Middle East – governments and water authorities are investing in desalination.

And then there is wastage – and the leakage conundrum.

Scale of leakage

Worldwide, more than 35% of drinking water disappears before it even reaches the users’ taps. On a global scale, more than 49bn.m3 of water is lost every year due to ageing pipes according to utility giant Suez.

Getting to grips with where the water goes once it leaves the treatment plant remains largely a thing of mystery, particularly in places like the UK where the inflows to wastewater treatment works are a combination of storm water and sewage.

“We are using a lot of data to help clients educate themselves with regards to water supplies – installing smart meters to help them understand how much of the water they are pumping out is reaching customers and when it’s being used,” says Fairfax.

“Very clearly we can understand how much we’re putting in, but what’s coming out of the other end has not been well-known, especially in the UK with our use of combined sewers.”

California

The situation in California is now chronic. It is now in its fourth year of drought and last May the State Water Resources Control Board was forced to impose an emergency regulation requiring an immediate 25% reduction in overall potable urban water use.

california water supply

california water supply

California must reconcile growing agriculture demand with very low rainfall

The stories are mind-boggling; the Golden State has now been forced into banning its restaurants from offering free water to customers.

The causes are in many ways complex. California’s Supreme Court has noted that “the scope and technical complexity of issues concerning water resource management are unequalled by virtually any other type of activity presented to the courts”. Yet they are also obvious – desperately low rainfall, high, and surging, agricultural demand (in an average year 80% of all potable water is used for agriculture), limited domestic conservation measures, and virtually no tracking of water use via metering and monitoring. But these causes are so fundamental it means it is almost impossible for the state to get control of the situation. How do you enforce a 25% reduction in domestic use when 30% of homes do not have a meter (according to the Pacific Institute). Regulations published in 2004 make the reduction compulsory for all municipal and industrial users only come into force in 2025.

State governor Jerry Brown has pinned his drought focus on an ambitious infrastructure project — a multi-billion pound plan, opposed by environmental groups, to build 60km of tunnels to transfer surface water from northern California (where it is relatively plentiful) to southern California (where the biggest agricultural users are). While that rumbles through the courts, desalination plants are being proposed up and down the Pacific coast, with one, the Carlsbad Desalination project, now open and claiming to be the biggest such operation in the western hemisphere. It will provide San Diego with 230Ml/day of drinking water – but at some cost.

 

Different ways to tackle scarcity

Water scarcity is a global issue, and all countries should be prioritising investment in solutions to tackle this problem, but the approaches taken may be different around the world, according to Amiad Water Systems chief executive Arik Dayan.

“In the developed world, a framework needs to be created for businesses to value water and assess their water risk – like the reporting of carbon footprint,” he explains.

“In the developing world, women spend 25% of their day collecting water and are in charge of water decisions at the household level – so involving and empowering women will be crucial in resource planning.

In the developing world, women spend 25% of their day collecting water and are in charge of water decisions at the household level – so involving and empowering women will be crucial in resource planning

Arik Dayan, Amiad

“The biggest use of fresh water is for agriculture, with demand increasing due to population growth, primarily in developing countries – and so it is key here to focus on improving the efficiency of irrigation systems.”

Amiad specialises in developing and marketing environmentally friendly filtration solutions for industrial, municipal, and agricultural use.

One of the biggest issues associated with water treatment is the energy required for many of the treatment methods, something that often makes effective treatment difficult in areas that lack the availability of cheap energy.

Reducing desalination water pressure

“Traditional systems have to operate at high water pressure, which requires energy,” Dayan explains. “We have countered this by developing highly efficient, automatic self-cleaning technology, allowing our filters to operate at a lower water pressure.”

He says that, where power is required, alternative forms of energy should be used wherever possible, and cites Amiad’s “Water For All” project with Mitrelli Group, which provides clean drinking water to villages in Angola, powered by solar energy.

Looking ahead, Dayan anticipates that we will continue to see technologies becoming more effective at removing a wider array of contaminants, which are being detected at ever-lower levels. “But we will also see an increasing focus on clean technology – solutions that conserve energy, use minimal chemicals, occupy less space and generate less waste,” he says.

However, technology is only part of the solution when it comes to tackling water scarcity. Education also has a vital role to play. “There doesn’t need to be a trade-off between education and technology in tackling water scarcity,” says Dayan. “It is vital that policymakers and organisations invest in environmentally friendly water technology to protect this precious resource for future generations. At the same time, education is key. It has to be a dual-pronged approach.”

Readers' comments (2)

  • This is a great piece, summarises the range of issues and threats while pointing at some of the directions we need to take to find solutions. We need a global mindset shift at all levels of society! Put it outside the paywall for all to read!

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  • A thought provoking article. One thought is "How is water scarity defined?" and another "How can it be greater than 100%?" Answers please.

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