THE GOVERNMENT should reject building new reservoirs "that may never be filled" as the answer to the region's water shortages, a report has warned.

With Thames Water proposing a massive reservoir between Abingdon and Wantage, with half the capacity of Lake Windermere, the new study says future water needs cannot be met by massive new developments.

The report, commissioned by the Campaign To Protect Rural England, judges the proposed 'Upper Thames Reservoir' at Steventon to be poor in terms of its local environmental impact and long-term environmental sustainability.

The CPRE believes the risks of abstracting water from the Thames will mean the new reservoir would not be filled. The impact of climate change makes it too environmentally damaging to pump out necessary quantities of water without severely damaging the river ecology.

The report - A Water Resource Strategy for the South East of England - has been written by CPRE South East hydrologist Graham Warren, who warns that despite heavy rainfall and recent flooding, the South East could be short of one billion litres of drinkable water a day without a new approach to water resources.

In a foreword to the report, Christine Drury, chairman of the CPRE South East, says: "The reality is that floods do not compensate for drought conditions, not least for reasons of water quality. 'Water, water, everywhere but not a drop to drink', has taken on a new meaning in 2007.

"The Government and the water companies haven't fully woken up to the new realities of water supply. Their strategies rely too much on building reservoirs that may never be filled."

Bruce Tremayne, chairman of CPRE Oxfordshire, said: "The situation can only be exacerbated by the Government's insistence that more housing development should take place at an increasing pace, seemingly irrespective of infrastructure.

"It must be hoped that the Government really digests what this report is saying and finally builds into its thinking that there really are environmental limits to economic and social growth, not least the availability of water.

"Building reservoirs only to waste the water through inefficient use is not part of the solution. As this report shows, building more sources of supply will not guarantee supply in the face of climate change, whereas careful use of the water we currently have will go a long way towards solving our problems."

And as well as having a substantial impact on the local landscape, the planned Oxfordshire reservoir will consume huge energy resources. It warns that Thames Water will still be leaking 26 per cent of its water in 2010, representing 725m litres a day, while the Upper Thames Reservoir will supply just 380m litres a day in comparison. In the South East as a whole, water companies still lose 21 per cent of the clean water from their pipes.

The call for reductions in leakages, chimes with the view of Oxfordshire County Council, which told Thames Water that it had jumped the gun by moving on to a second stage of consultation about the proposed reservoir near Steventon.

Keith Mitchell, the leader of Oxfordshire County Council, has said that he feared the process was being rushed.

He said: "It appears that some 70 per cent of the water held within the reservoir would be for London, with the remaining 30 per cent for Oxfordshire and Swindon. This reinforces the importance of looking at water resources at regional level, and in particular of looking at the proposals of the different water companies in total."

The report urges a greater emphasis on water recycling and a stop to water extractions from aquifers, while domestic metering and water-efficiency measures for new buildings need to proceed more rapidly.

It goes on to call for the water industry regulator Ofwat to be overhauled and the creation of a "superbody" to oversee water supply and demand.

Hilary Bennett, for Thames Water, said the leakage figures used in the report were out of date, adding: "We question the validity of some of the information in the report. Thames Water was never consulted.

"The proposed reservoir is essential to maintaining water supplies in Oxfordshire, Wiltshire and London. We will ensure local people are fully consulted about the design and appearance of the reservoir."

Thames Water hopes the reservoir near Steventon will be operational by 2020. The importance of the scheme is set out in the company's draft 25-year plan, published this week and called 'Taking Care of Water'.

Thames Water chief executive, David Owens, said: "More resources will be needed as we concentrate on managing demand and seeking new sources of water, as well as taking action to mitigate the impacts of climate change."

A public consultation on the draft document will end on October 26.