The defence reduces the risk of flooding to 416 homes and businesses in the town.
The first stage of the work will involve the Environment Agency replacing the existing defence wall from Tide Mill Way to the railway station. Later on the steel defences from the railway station to Deben Rowing Club will be reinforced with concrete and steel sheet piling.
The footpath will be kept open wherever possible and only partially closed for the minimum time necessary to ensure public safety. Diversions will be in place and all businesses and properties will be accessible despite the closures.
Graham Verrier, Environment Agency flood risk manager said:
Whilst the existing defences suffered some damage in the 2013 tidal surge, they did successfully reduce the risk of flooding to people and properties in Woodbridge.
However we need to be confident that any further flood events can be withstood for many years to come which is why this work is so important.
The first stage of the work is expected to take 3 months to complete and the existing standard of flood risk protection will be maintained throughout the works.