Ground investigation: Turning the tide

Happy times at last for those at flood risk in the Lincolnshire town of Boston: ground investigations have begun for the long-awaited £90M Boston Barrier.

The barrier is planned to reduce tidal flood risk to more than 20,000 properties in the town.

Yet GE sister title NCE reported in February that many in Boston felt the town had missed out on flood response support as politicians rushed to the Somerset Levels.

“The night Boston flooded, Nelson Mandela died,” a spokesman for Boston Borough Council told NCE in February. “We have not had the sort of media coverage [that Somerset has].”

The spokesman added that the barrier would have stopped most of the town centre flooding that occurred on 5 December 2013.

“The December flood made us more determined there should be no slippage in that project,” he said.

Now it looks like progress is being made.

Consultant WYG is carrying out up to 12 weeks of work on the area to be used for the flood defence scheme.

The Boston Barrier will sit within The Haven river to reduce the risk of a tidal surge and improve navigation on the town’s waterways. Almost 600 homes were affected by storms and a tidal surge last December.

Ground investigations for the scheme will be focused on the riverbed of The Haven, the Port of Boston and the embankment on the opposite side of the channel.

Flood defence walls

In the Port of Boston, the team will take concrete cores and dig trial pits. The information gathered will be used during the design of flood defence walls to run along the quayside.

Boreholes will be dug along the embankment opposite the port to gather information for the design of flood walls. The public footpath which runs along the Haven bank will be closed during the drilling works.

Ground investigation works will also take place within The Haven to identify the make-up of the river bed. Samples will be taken using a floating pontoon located on the south side of the river.

The work is being carried out by WYG for client the Boston Barrier partnership – consisting of the Environment Agency, Lincolnshire County Council, Boston Borough Council and Black Sluice Internal Drainage Board.

“This is an important step forward for the Boston Barrier project as [it] will inform a significant amount of the design work that we are doing now,” explains Environment Agency senior coastal advisor Mark Robinson.

“We are doing everything we can to reduce the risk of tidal flooding in Boston as quickly as possible.

“We will try and keep any disruption to a minimum but there is likely to be some noise while we drill the boreholes.”

Drilling will only happen from 8am to 6pm Monday to Friday.

Main construction of the barrier is expected to start in 2017 and be completed by the end of 2019.

Then the residents of Boston will be truly happy. As Lincolnshire County councillor Colin Davie says: “The barrier will provide Boston with one of the best standards of protection from tidal flooding in the country and will also allow the regeneration of the town’s waterfront – which will sustain and grow the local economy for years to come.”