Five to ten million pounds may be required to improve the safety of three Wanstead Park lakes which continue to be rated at a “high risk” of flooding despite a change new regulations, it has been revealed.

The park is managed by the City of London Corporation in collaboration with the Friends of Wanstead Park.

This cost estimate was revealed during a talk by Epping Forest Supt Paul Thomson at the Annual General Meeting of the Friends of Wanstead Parklands that was held on February 28.

Friends of Wanstead Parklands tweeted: “Supt focused on the implications for the Wanstead Park lake cascade of the recent EA decision to classify it as “high risk”. Thanked the Friends for helping to achieve clarity.”

A follow-up tweet added: “Supt said remedial works to lakes will cost £5 to 10m but part of cost should be usable as match funding for the long-awaited [Heritage Lottery Fund] bid.”

A Environment agency spokeswoman confirmed that while the criteria for assessing reservoir flood risks have changed, they would continue to be considered “high risk.”

She said: “The Reservoir Act (the Act) has recently changed and we now use a risk based approach to regulate them.

“Reservoirs are now classed as high risk if one or more lives would be at risk if they failed.

“Previously it was based on the amount of water above ground level in reservoirs.

“The three Wanstead Park lakes remain at the same risk level as before.

Now, specialist work is planned to help reduce the risk of the lakes flooding in the event of sudden heavy rainfall.

A spokesman for the City of London Corporation stressed that the group was doing all it could to fix the issue.

He said: “The Environment Agency has decided that three of the lakes in Wanstead Park are designated high risk reservoirs.

“We will be appointing specialist engineers this spring to advise on the studies needed to manage the dams for an increased level of public safety.”