Skip to content

Early action may have prevented further flood

Prompt action following a desktop exercise may have saved Wyberton from flooding on December 5, 2013, members of Black Sluice Internal Drainage Board's Northern Works committee were told.

Prompt action following a desktop exercise may have saved Wyberton from flooding on December 5, 2013, members of Black Sluice Internal Drainage Board's Northern Works committee were told.
During their annual inspection tour on Wednesday committee members were shown ongoing improvements being made to the Wyberton Marsh pumping station and its main feeder drain.
Members were told that immediate improvements made as a result of the findings of a desktop flooding exercise held shortly before the major flood event on December 5, 2013, probably saved the Wyberton area from inundation.

Desilting with councillors Displays a larger version of this image in a new browser window
Desilting work at Wyberton Marsh - from left, Black Sluice Internal Drainage Board Chief Executive Ian Warsap, and Boston Borough Council representative members Cllr Peter Bedford, Cllr Stuart Ashton and Cllr Stephen Woodliffe

The board was prompt in following up on a warning which kept the station's three powerful pumps operating for 12 hours during the worst of the flood, discharging three tons of flood water per second into the tidal Haven.
Landward feeder drains filled with tidal flood waters after defences were breached at Slippery Gowt. Earlier introduction of one-way tidal valves at Wyberton Marsh meant the pumps were able to continue operating, despite the high levels of water in the river, sending flood water away from threatened farmland and residential areas.
The pumps and associated electronics have been raised inside the pumping station so they are clear of flood water and a historic gravity-feed bypass pipe is to be excavated so that, in normal conditions, drainage to the river can take place without using electricity to run the pumps. It will also provide safer passage for eels. 
Members saw the work continuing with a massive 33-tonne dredger desilting the main feeder drain to increase capacity and flow rates.
The same machine will be put to work desilting the Hammond Beck at Chain Bridge in the next few days. Removed silt will be left on a triangle of land owned by the board near the bridge to dry out. It will be fenced and danger signs erected. Parents are asked to be sure their children are not tempted to investigate the muddy mound as it can be dangerous.
The inspection group was shown the North Forty Foot where silt up to six feet deep has been removed from the drain bed. It had not been desilted for 15 years. The drain was electro-fished in dammed sections prior to desilting works and the Environment Agency had been amazed at the numbers of fish. It is to use a 500-metre stretch of the desilted drain to encourage aquatic life to flourish by installing special environmental features.

Polluted Displays a larger version of this image in a new browser window
Environment Agency pollution pads being used to soak up petro-chemicals in one of the board's drains

A programme of improvement to drains and culverts will include using, for the first time in this area, a sophisticated ultra-violet culvert re-lining system from Germany.
This will avoid road closures and excavations. A flexible "sock" will be taken through the culvert, inflated tight to the inside of the culvert requiring repair and then the resin content hardened by ultra-violet light delivered from a device carried through on a rolling trolley.
Some culvert works will necessitate excavations and road closures and diversions will be in place from mid March through to the end of June, please look out for the traffic diversions.
Committee members were shown special Environment Agency pollution mats placed in ditches and drains near the Riverside Industrial Estate to trace petro-chemical pollution. The board is to crack down on illegal connections to its drainage system and discharge of pollutants. Those found to be responsible will have to pay clean-up costs: the licensed tip fees are from around £40 to £120 for every tonne of contaminated material removed.
Rainfall statistics taken at Swineshead Pumping Station showed that for seven months in 2014 actual rainfall was above the 25-year average, peaking in May when it was 247 per cent of the average and January, 2014, when it was up by 215 per cent. Only September was markedly below average at 22 per cent.
Chairman of the Northern Works Committee, Cllr Richard Leggott, stood down at the annual inspection meeting, but remains a board member. A new chairman will be appointed by the board later in the year.

Desilting Wyberton Marsh Displays a larger version of this image in a new browser window
Black Sluice IDB Northern Works Committee members watch dredger operator Kev Methley at work with the 33-tonne, 25-metre reach JCB JS330 machine at Wyberton Marsh