ARE harbour walls being repaired in Weymouth harbour high enough to withstand flooding?

Town councillors Luke Wakeling says the current work on a section of wall close to the Pavilion will be the same height as it was.

He has questioned whether this will be adequate considering what is known about sea level rises.

On the day he asked the question at an evening meeting of Dorset Council a Dorset Coast Forum meeting in Poole heard from a sea rise expert that Dorset would see at least a one metre increase in sea levels.

Cllr Wakeling told Dorset Council that he had measured the distance between the top of the harbour wall near the Lifeboat station and the water at the spring tide and it was only 12 inches short of over-topping.

“There are over 2,300 properties in Weymouth at risk of flooding from rivers and seas. What is Dorset Council planning to do, and when, to defend our town from rising sea levels?” he asked.

He asked why the work on Wall D did not include adding extra height, but was only replacing like with like, when the top of the new shuttering is less than 1 metre above the water level.

Cabinet member for the project Cllr Ray Bryan says that the work is adequate – for now, but agreed that more work may be needed in the years to come. He said the design for the wall had been based on Environment Agency modelling of likely flood risk and should be adequate until at least 2065 although if it did require extra height later, a band could be added to the top of the shuttering.

“The wall will require replacement in approximately 2070 and it would be prudent then to consider incorporating a flood wall into its design. The strategy mentioned shows the phasing of both replacing and raising of the harbour walls, in larger sections. This shows that some wall sections require raising now in order to maintain the required standard of protection, whilst others are able to wait for another round of wall replacement in approximately 2060,” he said.

Cllr Bryan also revealed that the harbour may need a tidal flood barrier by the same time, depending on the actual, rather than predicted, sea level changes.

He said that within the harbour existing flood walls would need to be raised and new flood walls installed within 10 years in some locations, but not all.

“In reality this will probably occur when harbour quay walls are replaced or significantly repaired,” he said.

“Along the coast, Dorset Council Coastal Engineers and the Town Council Beach Manager are using the newly developed Weymouth Beach Management Plan (BMP) in order to manage the beach more effectively as a coastal defence structure, alongside its existing amenity use. A set-back seawall along the promenade may not be required until 2060. The BMP also gives clear recommendations for coastal defence intervention over the coming decades.”