Investigations into a site for a new reservoir will begin this week.

South East Water will start digging boreholes on Tuesday at Clay Hill, near Ringmer.

If the reservoir is built, it is expected to be finished by 2015 and would supply 18 million litres of water a day to homes across Sussex.

It has been opposed by residents, who are concerned about the loss of an area of countryside that is home to a variety of wildlife.

The water firm will drill trial boreholes up to 30m deep.

During the next eight weeks it will also excavate shallower trial pits to help determine the ground conditions.

Archaeologists from University College London will work with engineers to ensure the excavated areas are monitored and any finds are recorded.

Badger surveys have already been carried out by South East Water's conservation team to ensure the animal's natural habitat is not affected.

The company will also work with environmentalists during the summer months.

James Grinnell, resources manager at South East Water, said: "It is important we undertake these comprehensive studies to obtain a clear and accurate picture of this location.

"These studies will help us determine if the scheme warrants further consideration for possible development, alongside other water resource schemes being looked at by water companies in the region."

The need for the studies has been supported by water industry regulator Ofwat and the Environment Agency.

The reservoir will only be built if the studies conclude that Clay Hill is the best solution to future water shortages compared to other resources being considered by Southern Water, Mid Kent Water and Portsmouth Water.

The development would also be subject to acquiring the necessary land and gaining planning permission and environmental consent.

Farmer Bob Peters, chairman of Ringmer Parish Council, said residents were resigned to the development taking place.

He said: "We don't want it. There are other places they could put it. The plan pinpoints this as one of the locations. We are just crossing our fingers."