Engineers working on the controversial Hampstead Heath dams project have presented a landmark proposal that would see the Model Boating Pond enlarged – but could spare all others from dramatic changes.

On Monday Heath bosses released a milestone report drawn up by engineering firm Atkins, which for the first time spells out how major works may be averted at most ponds.

The detailed 42-page report represents the first concrete sign that the City of London Corporation, which runs the Heath, is determined to come good on recent promises to scale down the £15million dams project.

The news will hearten conservationists who feared the worst after details first emerged in January 2011.

The Model Boating Pond, one of the most popular spots on the Heath, would still undergo significant changes in order to protect places like Gospel Oak in the event of a catastrophic storm.

But most others would remain virtually untouched in terms of appearance.

Jeremy Simons, chairman of the Hampstead Heath Management Committee, said: “Since the start of this project the City has been determined to find a solution which has the least impact on the Heath’s landscape and environment, while reducing the risk of serious flooding to the downstream communities.

“I’m pleased that the early indications from our designers in this recent report show this should be possible and that by concentrating work on two areas the amount of work elsewhere can be reduced.”

Under the Atkins proposal, the Model Boating Pond would be one of two areas expanded to hold large quantities of water in the event of a major flood.

It has been earmarked because it is the least natural-looking, according to Atkins.

On the Hampstead side, a patch of damp grassland called the Catchpit, north of the Mixed Bathing Pond, would be enlarged to do the same job.

Most other ponds would see some works, but they are classed as minor changes by comparison.

Tony Gilchik, chairman of the Heath sub-committee of the Heath and Hampstead Society, said: “There is still some way to go, but it’s moving in the right direction.

“They have come a long way from the original drawings that hit the press.

“They’re putting much more emphasis on doing less work than they were in the beginning.

“We’re encouraging them to do less and less work, and so far they seem to be picking up on the message.”

The report can be found at www.cityoflondon.gov.uk/pondsproject.

The public is asked to comment by email at pondsproject@cityoflondon.gov.uk or phone on 020 7332 3847.