Lack of rainfall this summer has highlighted a problem that has been exercising water engineers for some years. As the population continues to rise, how will the already stretched utilities companies cope with future demand?
Andrew Barker investigates
THIS summer the UK saw its worst drought in 100 years.
Cricket greens turned a sandy shade of yellow and rosebeds were left to wilt as seven water companies in the south-east imposed hosepipe bans, the highest number in a decade. As climate change, population growth and a shift towards smaller households put greater pressure on existing provisions, water companies are thinking big as they seek to close the widening gap between demand and supply.
A number of new multi-million pound schemes are being drawn up in the south-east, the most densely populated region that, unsurprisingly, has the least rainfall and the highest levels of water consumption. These include the building of two desalination plants, four reservoirs, and the expansion of two existing reservoirs.
No significant new water resources have been constructed since three reservoirs in the 1980s were built in the south-west, including Wimbleball on Exmoor. These days there is far more red tape to get through and none one of the proposed developments (see right) can go through without a lengthy public inquiry, and subsequent permission being granted from the Government and the Environment Agency. On top of this they face a frosty reception from environmental groups, philosophically opposed to developments of this kind.
The Thames Water desalination plant at Beckton is a novel idea on the science front. It uses the latest reverse osmosis technology to purify tidal flows in the East End. More impor tantly, it would supply up to 900,000 people each day - and provide considerable relief for the much maligned Thames Water, which reportedly loses nearly 350 Olympic swimming pools of water every day in leakages.
Although the project has already been denounced as energyhungry, it would certainly bolster supplies in the summer months when ground water is scarce. Sim ilarly, new reservoirs could collect rainfall throughout the winter months, which could be used in times of scarcity. But any new development on the scale of a reservoir is sure to be labelled as a blight on the landscape by the green groups.
According to Ian Allison, a water utilities director for Mott MacDonald , there is a st rong body of opinion that believes efforts to improve the existing infrastructure should be stepped up before embarking on any major new builds. His division are involved on a number of early stage works for the next regulatory period, 2010-2015, for most of the water companies in England and Wales.
Mr Allison says there is a clash of opinion in the south-east that sees the creation of new resources pitted against cutting down on demand as far as possible. 'It totally depends on the individual area and the company involved, ' he says.
John Lawson, chairman of the ICE Water Board and managing director of water and utilities for Halcrow agrees: 'There is a debate between economics and environmental issues. We should look again at all the resource options, taking into account the carbon consumption of a reservoir in Oxfordshire against that of a desalination plant.'
Among the ideological opponents is mayor of London Ken Livingstone. In June 2005 he directed the London Borough of Newham to block the proposal for the Beckton plant, even though the planning committee gave it a unanimous thumbs-up just a couple of months earlier. The outcome of the public inquiry is expected within the next six months.
But John Lawson, sees a major new resource of this scale as a necessary option for the south-east. 'The current drought is showing that our water resource balance is more precarious than we had thought. Something needs to be done in the southeast where all the companies are struggling at the moment.'
Mr Allison doesn't see a firm decision on a major new resource being made any time soon: 'Ken Livingstone has strenuously argued that there's no need for high energy projects, but the situation is not as black and white as that. The arguments range back and forwards.'
Mark Fletcher, director of Arup's water business believes rushing into a new project is not the way forward: 'It's not just about finding a solution, it's about understanding the whole cycle, ' he says. These days it is the norm for schemes of this kind to be a long time in the pipeline. 'Unlike 20 years ago, ' says Paul Chadwick, a technical director for Mott MacDonald's water division. 'In the Thames catchment area a project is likely to remain in the planning stages for 10-15 years, ' he says.
'It's a small, overcrowded county and difficult to find space.
When people living nearby object it's difficult to get these things through.'
But desalination plants have come a long way and are not the environmental scourge they once were. The Beckton plant would take water from the Thames' ebb tide, where it is brackish and nowhere near the levels of salinity of the North Sea. Mr Allison calls it a 'misnomer' of sorts to term it desalination, a technique widely used in parts of the world where water is in short supply, such as the Middle East.
Mr Lawson also observes the advances the process has made: 'Desalination is an evolving technology and we are now into membrane filtration plants and reverse osmosis. As a consequence the cost and energy consumption is coming down'.
In is not just the UK that is providing opportunities for the construction companies who work within the water sector. Arup is active in Poland, working with the Ministry of Environment on major projects in Krakow.
Importing models from abroad looks likely to become more common. One option would be to take the lead from the prescient New Yorkers of the mid 19th century, who invested in a rather ingenious system that brought clean water from upstate areas into the city itself. Every day the 8 million inhabitants of New York City receive 1.2 billion gallons of drinking water from outside the city.
This month the environment agency will publish a study on the viability of a national grid system that echoes the New York model. Surplus rainfall in areas like the North and West could be collected and fed down to thirstier areas but water mileage could raise the average household bill signif icantly.
'The ICE is querying whether there should be a transfer of water from wetter parts of the country like mid-Wales. Even with pipes all the way it is still a competitive strategy, ' says Mr Lawson.
But Mr Lawson sees getting the privatised water companies to cooperate as a big stumbling block:
'They find it hard to see beyond their own boundaries, to see the bigger picture.'
The emerging technologies for dealing with the treatment of sewage effluent are also improving according to Mr Lawson.
But he highlights the public's reluctance to receive second-hand waste water, albeit purified: a particular concern being the recirculation of oestrogen and the consequent effects.
Anglian Water conserves water at its Peterborough power station by using treated eff luent instead of tap water. It is filtered and the pu re water is used to generate steam, saving more than a million litres a day-enough to supply 6,500 homes.
One thing is for certain. Increased metering is imminent.
Supplier Folkestone and Dover Water Services wants to increase it to 90 per cent by the end of this regulatory period in 2010.
And the utility firm does not require customers' permission for installation.
Mr Chadwick sees the impact this has on the domestic economy as a key factor in reducing domestic consumption. He says: 'As more people become metered it will be possible to use a different tariff method. When more customers are tariffed you can introduce rising block tariffs where more water use is ref lected in the bill. The bill itself will increasingly become an incentive to use less.'
Around 80 per cent of UK households are not metered and so the majority of demand cannot be accurately measured.
'We need to get a better idea of commercial, domestic and industrial consumption. I think the water companies have to take the lead as they are the responsible guardian of the environment but there is more collective responsibility required as well. It looks like water companies are forging stronger relationships with larger players, ' says Mr Fletcher, clearly self referencing his employers at Arup.
Mr Lawson agrees. 'There is a certain amount of looking to Australia and California. In the UK we are almost unique in the low level of water meter penetration.
Someone in Australia would be astonished. I think management of demand like we've seen this year goes on a lot more in other countries and there's a lot to be learned from that.'
Proposed new resources
Broad Oak surface reservoir, Kent
Who: Joint venture of Mid Kent Water (40pc)/ Southern (40pc) /Folkestone & Dover Water Services (20pc); WH Atkins is consultant engineer
Where: Near Canterbury
When: Contractors on site 2010, completion date 2013
Peak supply: 55 million litres per day
Source: Surplus winter flows from River Stour
Cost: £100 million
Clay Hill surface reservoir, East Sussex
Who: South East Water; Black & Veatch are consultant engineers
Where: Near Barcombe
When: Completion date 2015
Peak supply: 18 m illion litres per day
Source: Surplus winter flows from River Ouse
Abingdon reservoir, Oxford
Who: Thames Water
When: Building to start in 2020
Peak supply: 345 million litres per day
Source: River Thames
Havant Thicket storage reservoir, Hampshire
Who: Portsmouth Water; consultant engineers are Entec UK
Where: Near Portsmouth
When: Planning application to be submitted in 2009 / 2010
Peak supply: 30 m illion litres per day
Size: Will hold 8.7 million cubic metres
Source: Havant and Bedhampton Springs (groundwater)
Cost: £30 million
Raising the level of Bewl Water reservoir
Water Where: Bewl Water
When: 2009 decision will be made
Peak supply: 14.3 million litres per day
Size: 40 million litre capacity
Source: River Medway and River Teise
Raising the level of Abberton reservoir, Essex
Who: Essex and Suffolk Water
Where: Near Layer-de-la-Haye, Colchester
When: Completion by 2014
Peak supply: 48 million litres per day
Source: Layer Brook, Ely-Ouse to Essex transfer scheme and River Stour
Beckton desalination plant, Thames Water
Who: Thames Water
Where: East London
When: Government decision expected in six months
Peak supply: 150 million litres per day (peak)
Source: Thames estuary
Cost: £200 million
New Haven desalination plant
Who: South East Water; Royal Haskoning is the consultant engineer
Where: Mid Sussex
When: Planning application to be submitted next year
Supply: Funded for up to 35 million litres per day
Source: Sea at New Haven