Hackney Marshes could be dug up for �10million disaster prevention measures to save thousands of families from the threat of flooding.

Environmental experts have recommended the excavation of 100,000 square metres of the north marsh alongside the Hackney Cut, which is the site of a wildflower meadow and new cricket pitches.

They say underground water tanks are needed alongside a new defence wall to protect Hackney residents from a potential two-metre-deep deluge – sparking concern from wildlife and sports lovers alike.

A report, which went before Hackney Council’s cabinet on Monday night, warned: “Hackney Wick contains a pocket of land which has a very high risk of flooding that could lead to a threat to human life and property.”

Rubble from London’s bomb-damaged buildings was dumped on the marshes – now the home of grassroots football – after the SecondWorld War, raising the level of the land.

But climate change coupled with the rise of new developments such as the Olympic site means homes are increasingly at risk should the River Lee, which runs into the Thames, burst its banks.

Hackney Council is responsible for flood protection and is using central government funds to research defences.

Excavation would cost between �6m and �10m, depending on whether it involved the disposal of hazardous waste.

Tim Evans of Hackney Marshes User Group said: “We are not intrinsically opposed to sensible flood measures but HMUG would want to know urgently what the implications for biodiversity would be.

“There has been a lot of mucking about with the marshes since the Olympics were announced and we would be interested to know why they want to put this on the wildflower meadow.”

Harry Hewat of campaign group The Lea Valley Federation called for a “more pragmatic approach” to flood protection while Johnnie Walker, chairman of Hackney and Leyton Football League, warned he would vigorously oppose the “disruption”.

“Surely they know when they build on this land that there’s a flood risk. They can’t go blaming global warming,” he said.

Hackney Council was unable to provide a response by the time the Gazette went to press.