September 2007
The Thames Barrier: Mk 2
Environment Minister Phil Woolas has said that he is expecting to receive a feasibility report for a new Thames Barrier within the next few weeks.
Recent floods across England, inflicting up to £3bn of damage have only served to highlight the potentially devastating consequences of leaving urban areas unprepared to counter the potential threat. The probability that London could flood has doubled since the completion of the barrier in 1983; that is from a one-in-2000 chance to a one-in-1000 chance. The go ahead for any new barrier would be decided some time in 2008, but Mr Woolas made it clear that "this is no longer an academic debate… People accept that it is a real threat but they don’t realise the imminence of it. Hopefully if there is any good that comes out of the floods, it will be that recognition." Indeed, in Gloucester, Mr Woolas warned that the Government would have faced the "biggest peacetime evacuation in history" had the emergency defences around the Welham electricity sub station failed, which they were one and a half inches from doing so.
A report published earlier in the year by emergency planning officers was graphic in its detail, warning that: "because of climate change, both the chance and consequence of flooding are increasing. Sea level rise, more frequent and higher storm surges and increased winter rainfall and more intense summer rainfall will add to the existing risk and it may not prove possible to improve fixed defences sufficiently to maintain or raise protection standards." Despite the assurance from an Environment Agency spokesperson that protection against a one-in-1000 year flood offered "a very high level of flood protection", the worrying picture of flood surges lifting people off their feet and leaving east London under several feet of water is dramatic and real enough to warrant serious concern.
The report continues that because of the local geography, floodwater would not drain away naturally and could be "present for weeks… the water will be brackish as well as polluted and this will cause additional damage. "A breach of the banks would result in a "torrent of floodwater".
With the same odds of matching 4 numbers on the national lottery, one would not put their house on the probability, but equally, one would not bet against it.
To address this, new defence system proposals are being drawn up for an area east of Woolwich. Ideas include the construction of a massive new barrier at Sheerness, or even opening up land to the east of London, creating large flood plains as an additional backup. In any case, experts have given a definite deadline, stating that by 2030, the Thames barrier will no longer be able to cope. When built in the 1980s, planners foresaw the need to close the barrier perhaps a couple of times a year at most, and this was the case up until 1990. Thereafter, the average has risen to five times a year with an unprecedented 14 closures in 2003. Moreover, the Environment Agency has noted a 6.6cm rise in the Thames’s mean tide each year.
Where the traditional approach of raising and strengthening river walls and embankments proved fairly successful in the past, the risks have continued to increase exponentially. In spite of their permanence and low chance of failure through human error, effects on the tourist economy would be significant, and it is not a solution that Londoners are keen to see. Whatever the outcome of the latest report, it is clear that inaction is not an acceptable response.
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