THAMES Water has failed to properly investigate cheaper alternatives to a £1bn Reservoir between Wantage and Abingdon, campaigners will tell a public inquiry today.

A public inquiry into the water company’s plans for the next 25 years is expected to finish on Thursday, after taking evidence for two months.

Brigadier Nick Thompson, chairman of local residents’ campaign, the Group Against Reservoir Development (Gard), said he hoped Environment Secretary Caroline Spelman would rule out the reservoir, regardless of the recommendation of planning inspector Wendy Burden.

The reservoir, which could cover an area of almost three square miles, is part of Thames’s draft water resources management plan, outlining how the company aims to meet predicted demand in the region until 2035.

Brig Thompson said: “The inquiry has been thorough and fair and the opposition to the reservoir has been extremely strong. We hope the Government doesn’t allow the reservoir to go ahead, but we won’t find out until an announcement is made, probably before the end of the year.

He added: “The reservoir is the most expensive answer to meet water demand figures and transferring water from the River Severn would cost half as much.”

Gard’s lawyer Nathalie Lieven will argue that Thames Water has failed to properly assess a number of alternative ways to meet future water needs, which would be cheaper, more sustainable and more efficient.