Ian Moodie is our flood management and access adviser.
There has been much debate recently about the role of farming in preventing flooding following the extensive, catastrophic floods across the Somerset Levels.
Several commentators have suggested that attenuating (‘slowing the flow’) of water upstream, could prevent the flooding we have seen. This is a crass over-simplification of the situation.
Slowing the flow, encouraging water to infiltrate into the land can have a role in helping reduce flooding, but without works like dredging downstream to maintain the capacity and conveyance of our lowland rivers, we are just pouring water into a bath with the plughole blocked.
This is especially the case on the Somerset Levels and Moors where years of neglect to maintain the Rivers Parrett and Tone by the Environment Agency have resulted in rivers with less than two thirds of their intended capacity to convey water. Prolonged and persistent rainfall has resulted in 11,500 hectares now lying under 65 million cubic metres of water. To expect farmland in upland areas to attenuate such large volumes of water is simply unrealistic.
This is not to say that such techniques to capture and hold more water on farmland, slowing the flow downstream, should not have an important role to play in reducing flooding in smaller catchments and upland areas, especially if couple with properly managed watercourses downstream.
However, tree planting and attenuation needs to be carefully implemented so as to avoid creating permanently wetted areas which can increase run off downstream or too much woody material which can be dislodged by flood water and trapped downstream under bridges and other obstructions causing greater misery. Therefore, such techniques must not be seen as a panacea, and should not be expected to significantly reduce flooding in more extensive lowland floodplains.
For this reason we oppose the suggestion of a requirement for farmers to have to capture water on their land in order to access grants from the EU. Instead agri-environment options, funding and targeted guidance that facilitated farmers to use natural processes to help control flows in, over and around farms would be welcome.
Catchment Sensitive Farming is just one example of how that is being implemented currently. However, this needs to be couple with support for good management practices in lowlands to remove silt and debris and manage vegetation that constrains the flow and capacity of our watercourses. Here, it is hoped that the River Maintenance Pilots can identify good practice and point toward smarter and better regulations which facilitate farmers doing maintenance in an environmentally sensitive manner.
Ultimately, what is needed is a balanced approach, improving soil infiltration and attenuating flows where appropriate upstream, but enhancing capacity and conveyance in our lowland watercourses. We've got to start investing in lowland areas like the Somerset Levels and look again at how the government prioritises where it invests money in flood risk management.
Perhaps most crucially of all we need to reverse the chronic underinvestment in maintenance being repeated across the country as cut backs to the Environment Agency’s revenue budget have disproportionately resulted in less funding for dredging, vegetation management and fixing existing defence structures whilst flood warnings, monitoring and capital flood defence schemes have been protected.
This needs to be rebalanced, to recognise the important role of our rivers in conveying water. Government funding for the maintenance of our rivers and existing flood defences needs to be transparent and ring-fenced from other investments so that it is clear just how much or little is being invested.