Highly controversial dam engineering works on Hampstead Heath are merely “heavy gardening” according to the contractor appointed to carry out the works.

Ham & High: The guided walk passes a defaced board about the dams project. Picture: Polly HancockThe guided walk passes a defaced board about the dams project. Picture: Polly Hancock (Image: Archant)

Bam Nuttall has played down the scale of the contentious £15million flood defences project, which many fear will permanently scar the cherished green space.

The construction and civil engineering firm was this week unveiled as the chosen contractor by the Heath’s superintendent Simon Lee, who said: “This is a contractor working on Crossrail at the moment, doing big civil works.

“Their view is that this job is not heavy in terms of engineering. They use the term ‘heavy gardening’ in terms of the scale of works, this is not major engineering.”

He added that the contractor was “by no means” the cheapest option, saying: “We’re spending a great deal to get the right contractor.”

The news comes as the City of London Corporation’s top dam expert, panel engineer Dr Andy Hughes, revealed that the project will “create havoc” for as long as two years.

Mr Hughes and Mr Lee were speaking as they led a group of residents on a guided walk of the ponds on Tuesday to discuss the proposed changes, which will see most of the Heath’s dams raised by as much as 18ft, to stop them failing in the event of an extreme storm.

It is the first time representatives of the City, which runs the Heath, have publicly indicated how long the project could take.

“Yes we’re going to create havoc for a year or two,” Mr Hughes said. “But I want to come out the other side and say, ‘What was all the fuss about?’ because we have made it better.”

Mr Lee said works were likely to be phased to minimise the impact, taking place on three ponds at a time while others remain in use.

Meanwhile, scores of residents and swimmers reaffirmed their fierce opposition at a heated public meeting on Monday, hosted by the United Swimmers Association of Hampstead Heath at the United Reformed Church, in Pond Square, Highgate.

The leaders of the Dam Nonsense campaign announced that they will launch a judicial review challenge as soon as the City submits a planning application to Camden Council.

A motion was passed urging the City to join the Dam Nonsense campaigners in seeking a judicial ruling to clarify the disputed legal position.

The City says the work is mandated by reservoir legislation, but opponents challenge its interpretation of the law.

Robert Sutherland Smith, chairman of the United Swimmers Association, said it is shocking that the City is prepared to “misallocate” £15m that could better be spent on “worthwhile activities” such as schools and the arts.

Some swimmers also voiced fears that the plan was about making money from the ponds.

Geoff Goss, chairman of High-gate Men’s Pond Association, said: “They’re going to put a wall around the men’s pond.

“We’re looking at a massive reconfiguration of the ponds and having a system to walk in where it’s going to make it easier for them to impose charges.”