The Flood Barrier

With Jack Chapman and Tom Gondris and 35 others (a third from the Environment Agency) I attended this all-day event at the Holiday Inn. Everybody finished more knowledgeable about flood risks in the Gipping Valley and Orwell Estuary, possible solutions and their costs and their effects, both wanted and unwanted. We also felt we had been able to communicate our own wishes and fears and listen to other people's.

The facts are that Ipswich is very likely to flood to a great depth – 2.5 metres in the dock area – if preventative measures are not taken. Up to 2,500 homes would be affected and over 250 Listed buildings in the medieval core of the town. It would reach the police station in Civic Drive. Clearly action is essential. The solution needs to prevent hold up to excessive Gipping flows in case of torrential rain, as well as preventing huge spring tides backed by a North Sea low pressure system with north westerly winds. It needs to be effective, affordable and visually attractive. Furthermore, it should have a minimal environmental effect on the natural habitat, which is hard to predict.

The solution will be a small Thames-type barrier, called a quadrant lift, placed at the seaward end of the New Cut. It will have a minimal effect on navigational rights, which are paramount on a tidal river. (The man from Debbages seemed quite happy.) It will not prevent back up flooding in the Gipping. When down, the structure is not a major visual intrusion; it also acts as a velocity control structure. Additionally, the lock gates have been replaced. Downstream defence for Wherstead Road and the docks would be ensured by heightened embankments and walls, to be disguised with grasses and other vegetation.

The barrier will cost £45 million. This money seems fairly certain but is by no means guaranteed. It was clear that the Environment Agency feels the biggest risk to the scheme is the withdrawal of central funding.

It became clear that there was no way that the EA would allow a vehicle, cycle or pedestrian crossing at this site. It was not their brief to relieve communication or transport problems; the barrier could not work as a bridge and there were major Health and Safety considerations.

Moreover and unfortunately, they could not allow the Gipping between Stoke Bridge and West End Road weir to become non-tidal and therefore an attractive town centre water space.

I had a lengthy discussion with the EA person responsible for local planning issues. He said that they would continue to insist on their current requirements until the barrier was built, as there was always the risk of a flood occurring before it was operative. Even then, they would insist on sensible prevention and escape measures, as it was always possible for the barrier not to come up or, perhaps worse, go down. At least one pessimistic engineer preferred high walls as they always worked!

Mike Cook