In the wake of the current, extensive flooding across large parts of Somerset, I thought it might be helpful to share the Environment Agency’s current position on flood risk management in the County. It contains some useful information with regard to the current hot topic of ‘dredging’.
“Dredging and clearing channels are important parts of the Environment Agency’s maintenance regime. In the year to April 2013 we spent £45m of our £170m national maintenance budget on channel maintenance which includes dredging, de-silting and obstruction removal along with weed control to clear channels.
However, in many circumstances it is not the best long term or economic solution compared with other flood risk measures. We therefore focus our efforts on dredging at those locations where it has a proven benefit of reducing flood risk.
De-silting and dredging would not reduce the flood risk on all the rivers on the Somerset Levels due to their tidal nature. De-silting would have some flood risk benefit for the Rivers Parrett and Tone, but would not prevent flooding in circumstances such as those currently being experienced.
Flooding would still happen, but increased channel capacity would help to get water off the land more quickly. Significant ongoing maintenance would also be required to sustain these flood risk benefits. The larger the channel in the tidal reaches, the more rapidly tidal silt will accumulate.
Work commenced in November on the de-silting of ‘pinch points’ on the River Tone and working towards the River Parrett to maintain river flows. This is an interim step to maximise the capacity of the existing system whilst the feasibility of longer-term approaches are explored with partner organisations.
Environment Agency staff continue to work around the clock across the country to warn and inform people of flood risk, and work with partners to manage the impacts of recent flooding.