Now the worst of the UK storms seems to be over (fingers crossed) people are turning to what can be done to stop this from happening again and the area that is receiving the main bulk of attention is the widespread flooding on the Somerset levels. most areas are still underwater now, although the levels are starting to do down and there have been fierce debates over what is the best way to stop flooding like this from happening again.
Perhaps the main source of debate has been that over dredging the rivers that have caused the most trouble. Dredging involves removing sediment from a river’s bed making the channel deeper and therefore meaning the river can take more water when in flood. however this has been controversial for many reasons. firstly, dredging does not do a river much good. the sediment in a river is full of nutrients for wildlife and also it provides a habitat for many as well. secondly, dredging will have to be carried out repeatedly if it is to be effective as rivers will replace the sediment as the water erodes rocks and when material is washed into the river off the land. but the most important area of debate has been that dredging may not actually work at all. in the case of the recent flooding, it has been argued by several experts that even if a river was dredged it would not have prevented flooding as there was simply too high a volume of water that was falling on saturated ground and entering the river, meaning that even with a deeper river channel would not have been able to cope with that amount of water. dredging cannot prevent flooding in these sorts of extreme situations the only upside is that dredging may be able to make the water drain away a bit faster than if the river wasn’t dredged. also unless the entire river from source to mouth is dredged, which is highly unlikely, dredging can cause issues of flooding for people downstream of a dredged area as when an area of river is dredged the removal of the sediment means the river flows at a faster velocity as there is less friction from the sediment on the water. this faster flow of water will mean that when it reaches an area downstream that hasn’t been dredged it will back up ans flood that area badly instead. of course it is hard to tell people who have had their homes underwater for months that dredging isn’t going to work as they are desperate for a solution, but in my opinion dredging is not the solution to a flood of this scale.
there are other ways to prevent this flooding from happening again though. some ideas have come from looking at examples of what is done in other countries to prevent flooding. in the USA many homes have been designed to have garages on the bottom floor and living spaces on the top floor so the most valuable parts of a home are at less of a risk from flooding and this might be a better solution to building houses on stilts like in the Netherlands. also new regulations should be introduced stating that any new homes that are built on a floodplain should have adequate protection from floods. also one major problem on the Somerset levels was that many people couldn’t escape flooded areas as the roads we flooded too. therefore it has been suggested that roads should be built on a bank of higher ground meaning they will remain open in the event of a flood.
Also levees alongside a river are a great way to reduce the likelihood of a river flooding. they allow a river to extend naturally to a certain point. However, I think that in order for levees to be more effective, as many flooded rivers already had levees which failed, a levee should not be built right next to a river but a certain distance back from the river with a floodplain between the levee and the river channel. this floodplain could be used as a recreational area when the river isn’t in flood, so that when the river floods the land damaged in front of the levee isn’t valuable; at the most it will be a slight inconvenience. therefore the river is allowed to use its floodplain, as the floodplain is the river’s natural way for responding to a flood, but only to a certain extent. this means the river can naturally expand in a flood without damaging valuable land or property.
Finally, I think one thing we must remember when trying to tame rivers is that it is a natural thing for a river to flood and we must not restrict it too much or else we could make the problem a whole lot worse.
- information on dredging sourced from: http://www.bbc.co.uk/news/science-environment-26175210
- further information on long term flood management strategies sourced from: http://www.bbc.co.uk/news/science-environment-26326560 and http://www.bbc.co.uk/news/uk-26284047
Credit for the above sources belongs to the BBC