Residents in Oxford are being given the chance to shape a multi-million-pound strategy to protect the city from flooding over the next 100 years.

This week the Environment Agency is launching a 12-week consultation into a its proposals, including spending up to £100m on a flood relief channel as wide as the River Thames, west of the city.

The 17-page consultation document is being sent to more than 2,500 homes in areas most at risk of flooding.

Environment Agency spokesman Keith Hutchence said it was the biggest consultation on flood risk management ever undertaken in the city, which suffered serious flooding in 2007 after torrential downpours on July 20 swelled rivers across the county.

More than 3,600 homes and businesses are at risk of flooding in Oxford. There were also major incidents in 2000 and 2003.

Mr Hutchence said: “We want to reduce the risk of flooding to people in their homes and businesses, but we’re not looking at a quick fix – we’re looking at flooding in Oxford over the next century.

“We have come up with options ranging from doing nothing to spending millions of pounds creating new watercourses and channels west of Oxford.”

Mr Hutchence said one of the aims of the strategy was to make full use of existing flood plains outside the city.

He said: “We’re talking to Oxfordshire County Council, district councils, Thames Water and Network Rail, but we’re also talking to local groups and parish councils.

“We’re spreading the word and getting out to talk to people. We want everyone living in Oxford to be able to have their say.”

The proposed channel west of the city could run from Binsey to Redbridge.

Agency manager Geoff Bell said: “It isn’t going to be a nasty great concrete channel. It will blend into the existing landscape.”

As well as the channel, the agency is consulting the public on whether bunding — large earth barriers — could be built to protect the city or whether more portable defences, such as the £180,000 barriers recently bought to protect Osney Island, should be used.

The consultation document also suggests smaller projects to alleviate the risking of flooding and ways of protecting individual properties.

If the agency is able to secure funding from the Government or European Union, or both, work on implementing the strategy could start by 2013.

The agency’s proposals can be seen online from Wednesday at environment-agency.gov.uk/oxfordflood and an exhibition about the plans will be staged at Oxford Town Hall, in St Aldate’s, on Saturday, March 28, between 10am and noon.