Work on Ipswich’s new £30 million flood defence barrier has formally started with a ground-breaking ceremony on the Waterfront Island.

The barrier is the final section of a £53 million flood defence scheme for the town which should protect it from almost all flood threats.

The scheme strengthens the existing flood defences, built in the 1970s, which only offered limited protection from floods.

Funding for the work has come from the Environment Agency, the Local Enterprise Partnership, Ipswich Council and central government.

Once complete in 2017, it will protect the town from all but the kind of flooding problems that could be expected once every 300 years.

The 1970s defences currently offer protection from the kind of events expected once every 20 years.

Environment Agency area manager Dr Charles Beardall said: “These defences are very important to the town to offer the kind of protection that it needs.

“We have seen the devastation that floods can have in other communities and this work should offer a good level of protection.”

The flood defences will protect 3,700 properties, including important buildings like the fire station, the main police station, and council offices. It will protect up to 4,000 jobs.

The 1953 floods had been a one in 200-year occurrence, so the barrier would have protected against a flood on that scale.

Mark Pendlington from the New Anglia Local Enterprise said it was vital to protect major commercial centres.

He said: “You only have to look at incidents at Tewkesbury and Carlisle to see how devastating floods can be to communities. We felt it was vital to provide funding to protect one of the most important towns in the region.”

The first stage of the work is to divert mains electricity cables which run to Felixstowe before work on the barrier itself can start.

The barrier itself will use a similar technology to that on the Thames Barrier which protects London from tidal surges – and will cross the New Cut from the Island site to the West Bank.

Earlier stages of improved flood defences included raised banks and the new lock at the entrance to the Wet Dock.