Wednesday, 12 February 2014
Creative engineering needed to end flood threat
The rays of sunlight streaming through the winter branches on a calm February midweek morning may get you thinking that all is well in the world. The glistening trunks and limbs of the trees, the saturated ground and the dark, brooding and oncoming clouds from the south-west imply a different scenario. The brief warmth turns to cold and a chill wind brings more rain, rain that has been the dominant feature since well before Christmas. The Somerset Levels have been flooded for months while the upper reaches of the Thames, where development is denser, are experiencing incremental water-level rises that have now reached a critical level. The emergency services have been scrambled and now work around the clock in both the Westcountry and the Thames catchment in an exercise of disaster management as opposed to risk-reduction. Did they see it coming? Well, yes, but certainly not this soon. Many climate-change academics say that the weather patterns we are experiencing now were predicted but not expected for 30 years or more. The long-term flooding threat has been seen by the Environment Agency as coming from rising sea levels, as set out in the Thames2100 plan, and the upper Thames (River Thames Scheme). The Thames Barrier would be rebuilt mid-century and the riverside developments adorning both banks eastward face the installation of an elevated flood-protection wall. The current problems are with the upper catchment areas where, again, development and its hard surfacing increases run-off while changing farming practices have increased ground level saturation. This, with the Somserset Levels in mind, was laid out by environmentalist George Monbiot recently, where Monbiot criticised environment secretary Owen Paterson, from farming stock himself, for advocating the stripping of upland areas of vegetation and opting for a more canalised, culverted and straightened riparian landscape in order to flush water through. My old friend Paul Caudwell, a farmer in Oxfordshire, was prosecuted by the EA for doing just that four years ago. From a London, or Thames, perspective the stripping-out of vegetation was completed 200 years ago and, apart from some soft-engineered retrospective flood alleviation within catchment greenspaces, most of the riparian border landscape has been replaced by hard-surfaced car parks, driveways and shopping malls. In 2009, at the same time that Paul was battling with the EA, I took part in a real-time London flooding exercise with the Fire Service, Police, NHS and councils to detect any gaps in preparedness. Manning the phones, and with real resources at our disposal, we were given scenarios where sea levels, and therefore London flooding, were rising all the time. Borough Councils were busy, within the ficticious scenario, bussing people out of estates, caring for the elderly and infirm; hospitals were at bursting point etc. Now and then a curve-ball would be thrown into the mix like civilian dissorder, looting and fires. It was an all-day exercise and while generally it was successful, there were some Councils that didn't even get involved and refused to pick up the phone. Some of these said that they did not have the manpower, due to cuts, to get involved and some simply said it was too 'pie in the sky' to get involved with. Maybe some of these London Borough Councils will be scrabbling though their flood strategies as the reality is upon us. The problem is solveable but the answer is not to dredge, and return to the hard engineering of the last century, but to introduce create alleviation measures in the upper catchments. The Government must trust the Environment Agency strategists, flood experts and geomorphologists and give them the money to sort it out while politicians cut the rhetoric and take a back seat.