Ofwat is proposing a 17% increase and not the 35% SWW suggested

The regulator Ofwat is moving to limit rises, although the region will still have the highest bills in the country.

Ofwat proposed that over the next five years the region's average home will see its annual bill rise from �361 to �422 - not the �487 SWW suggested.

SWW and the regulator will carry out a debate for four more months before Ofwat makes its final decision.

Cleaning up the coast line has been an enormous task Bob Baty, South West Water Have your say about water bills

Dr Noel Olsen, of WaterVoice South West, said: "This is better than we feared, but it's still unaffordable for many.

"We need government help because these bills are disproportionate to the rest of the country."

The news may mean delays in cleaning up the environment. South West Water (SWW) has already invested about �1bn cleaning up coastline, but said it still had a lot to do to meet environmental standards.

SWW chief executive Bob Baty said: "Cleaning up the coastline has been an enormous task over the last 15 years. We have to borrow that money because we don't get sufficient money in from customers on a daily basis."

SWW said it would be a challenge to meet environmental targets if bills only go up by the 17% proposed by Ofwat and not the 35% it suggested.

SWW is now trying to work out is whether the limited bill increase means it is being given official license to relax some standards.

Ofwat said it had closely scrutinised South West Water's proposals to ensure that customers pay no more than is necessary if the company is to continue to deliver a safe, reliable and efficient service.

Philip Fletcher, Director General of Water Services, said: "Although the average rise in bills is nearly twice the average for England and Wales as a whole, I am convinced it is necessary.

"I am very conscious that these proposals may present problems for customers on low incomes. We have worked hard to ensure that the price limits are no higher than they need to be."