Providing water and sewage facilities for 200,000 new homes in south-east England will involve huge costs and could lead to environmental problems, MPs have been warned.

They were also told residents in the new developments could face water shortages and flooding.

The Environment Agency said that developers should pay part of the �4bn needed to protect the Thames Gateway area - where 40,000 of the houses announced by John Prescott are set to be built.

The water industry accused the government of failing to properly consult them on the challenge of providing facilities for the development.

English Nature said it was concerned that water could be diverted away from nature reserves and called for wildlife to be protected under the plans.

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How the countryside will change

Peter Madden of the Environment Agency warned the Commons Housing Select Committee that existing flood defences will only protect the Thames Gateway area until around 2030.

No one has come to us and said 'what do you think of this'? Jacob Tompkins - Water UK

The agency believes that the defences - stretching from the Thames Barrier out to the coast need to be improved.

He said that building levies should be imposed to help meet the cost.

Mr Madden said the location of the developments should also be carefully considered: "We want to make sure what we build does not increase the risk elsewhere."

'Hosepipe bans'

The MPs also heard that the problem of supplying water to the homes and giving them proper sewage facilities had not been given proper consideration.

Prescott's plans: 2003-2031

London-Cambridge-M11 corridor: Between 250,000 and 500,000 new homes Milton Keynes: Up to 300,000 new homes Thames Gateway: Up to 40,000 new homes Ashford: Up to 31,000 new homes

Jacob Tompkins, of water industry body Water UK, said all four areas earmarked for development faced water shortages.

He told BBC News Online: "We're building in the most water scarce area of the country and the UK has less water per head of population than any other country in Europe.

"We would not want hosepipe bans or constraints, but you may be looking at that."

Mr Tompkins said the water industry needs years to prepare for such major construction work.

He said: "No one has come to us and said 'what do you think of this'? Suddenly we have heard that all these areas are going to have all these new houses."

Mr Tompkins said a way to supply the new estates would be found, but that the cost could be as high as �10,000 per house.

He said the government needed to consider the fact that some of the houses are planned for flood plains.

Covering "vast areas" in concrete could also mean rivers bursting their banks after heavy rainfall because water will run off the land more quickly he said.

'Huge concern'

English Nature, the government wildlife agency, said it was concerned about the potential impact on the environment.

Senior planning advisor Jonathan Price said: "The huge growth in the South East, at the expense of other regions, is of huge concern and arguably the South East is reaching it's capacity."

"It's absolutely paramount that the new growth is accordingly planned."

Mr Price said the developments should include green space for the people living there, along with nature reserves, water ways and other protected areas for wildlife.