HAMPSHIRE residents are expected to see their water bills rocket over the next five years.

The huge 45 per cent increase that has been proposed will see annual costs rocket from the current £247 to £358 by 2009.

If regulator Ofwat approves Southern Water's proposals, it would be the biggest hike in the country.

Company chiefs say the rise is necessary because of a planned £2 billion investment programme to maintain and improve services.

Water watchdogs admitted customers would be "shocked" by the scale of the possible increases, which would be an average of 7.7 per cent annually for the next five years.

Residents in the New Forest area, who are covered by Bournemouth and West Hampshire Water, would face a 12.5 per cent rise from £104 to £117 in five years. That figure does not cover sewerage, which is run by a separate company.

The Daily Echo has previously reported how householders in Fareham and Gosport faced increases by Portsmouth Water, which also does not cover sewerage, by 21 per cent by 2009 to £88.

The average rise in water bills across the country would be 29 per cent to £310 by 2009.

Earlier this year the government urged companies to make continued improvements in drinking water quality and the environment but also take account of the effects on people's bills.

Richard Sturt, chairman of WaterVoice Southern, which represents Southern Water customers, said: "We believe that most customers will be shocked by the scale of these proposed price increases, particularly when the water company intends to impose a significant increase in the first year, 2005/06."

Next year householders could see rates rise to £289 or 17 per cent.

Mr Sturt said: "We accept that the companies need to invest heavily in their water supply and sewerage services in order to maintain service standards and meet the increased demand for them. However, we are concerned that in most cases the biggest investments are dictated by the environmental programme determined by the government, which comes at a great cost to water customers."

Southern Water said the increases would pay for improved water supply works, water mains, waste water treatment works, pumping stations and sewers.

Managing director Stuart Derwent said: "Our next five years will be dominated by the need to deliver a very large investment programme.

"We have done our utmost to consider the investment plans against the overriding need to moderate prices to customers but water charges will have to rise to meet the enormous cost."

Ofwat will publish draft decisions on the plans in August.

Director general of Water Services Philip Fletcher said: "We will work hard to ensure that price limits are no higher than is necessary to enable companies to raise finance and deliver all these improvements."