The proposed work on Hampstead Heath ponds is to prevent the risk of flooding in residential areas.

Major works to guarantee the safety of Hampstead Heath’s ponds in the event of extreme weather are “absolutely inevitable’’ because of the risk to public safety.

Professor Andy Hughes, the City of London Corporation’s director of dams and water resources, said this week that the risk of flooding in residential areas could not be ignored.

“There are people who believe this could never happen but the reality is that it could, in 25 years’ time or tomorrow,’’ he said. “There has already been one dam failure on the heath. When one dam in a chain fails, they can all fail.’’

Prof Hughes spoke out after Environment Agency chairman Lord Smith surprised guests at a heath management committee dinner by stating there was no legal requirement forcing the corporation to carry out work –contradicting the committee’s claim that it had no choice because of changes in legislation.

Speaking from an international conference in Prague, where he delivered the keynote speech and presented a paper on climate change, Prof Hughes said he was now seeking a letter of clarification from the government agency to enable work to proceed.

If that was not forthcoming he would call for a statutory inspection.

“Any inspection would certainly highlight a potentially dangerous situation for parts of Camden if the dams overflowed and the Environment Agency would undoubtedly order the corporation to carry out works,” he said. “If the corporation refused, the agency has the power to step in and do that work.

“In my view, it is absolutely inevitable that the work should and will go ahead, but only after wide-ranging consultations.’’

He added: “A great many people are passionate about the Heath and I share that passion. I have grown to love the place and there is so much we can do to reduce the visual impact of the works on this beautiful landscape. There is no question of a “manicured” finish.

“I want every interested organisation to be involved and to influence how we proceed. My ambition is for people to come up to me afterwards and say, “you’ve done a good job” and perhaps add that they had forgotten we were ever there!’’

The design phase and public consultations could take up the whole of 2012 with staggered site works beginning in 2013 and taking two years to complete.

Prof Hughes believes the safety considerations went “under Lord Smith’s radar’’ because of a quirk in the system.

“The corporation’s hydrological analysis was the most comprehensive I have ever seen,’’ he said. “It clearly identified the need for works because of an unacceptably high risk of flooding but this remained under Lord Smith’s radar because there is no mechanism for this kind of information to be fed back into an official recommendation that the agency would then legally enforce.”