Climate change means we need more joined up thinking to prevent flooding and storm damage
Andy Williamson is right to say that is a more cost effective, naturally efficient alternative than blowing 拢4.2bn 鈥� twice as much as we need 鈥� on London鈥檚 super sewer.
As he says, it鈥檚 an urban problem not just a London problem. But it鈥檚 potentially more urgent and on a far bigger scale, involving us all. London is just first in line.
James Hansen, a respected climate scientists, warns that ice melting on and around Greenland and Antarctica will cause much faster rises in sea level than mainstream predictions. We鈥檙e likely to see several metres of sea-level rise this century and more super storms.
New Scientist magazine says most glaciologists agree with his predictions of sea level rise, though not the speed of change. But it says 鈥渙fficial鈥� predictions have been too conservative time and time again, and Hansen has a history of predictions that are bang on the money. That doesn鈥檛 mean he鈥檚 right, but it makes you think.
If he鈥檚 right we鈥檒l need more than today鈥檚 Thames Barrier to protect London from flooding and North Sea surges. The barrier was designed to close 2-3 times a year. It shut just 8 times in the 1980s, but 31 times in the 1990s, 80 times in the 2000s, and 55 times from 2010 to mid-2014.
What affects London today, will affect the rest of us tomorrow
Significantly, 41 of these recent closures were to protect against prolonged heavy rainfall in the Thames catchment area, not tidal surges from the east. And heavy rains and more frequent storms are having other effects on London鈥檚 homes and businesses.
Contracts for the 16 mile long Thames Tideway Tunnel, London鈥檚 super sewer are about to be signed off. It will run from the west to the east through the centre of London, mostly under the river Thames. It鈥檚 one of the largest infrastructure projects in Europe.
Sir Ian Byatt, a former head of regulator Ofwat, says: 鈥淢y big objection is it鈥檚 not necessary.鈥�
Thames Water customers will pay an extra 拢80 a year surcharge in perpetuity.
The government and Thames Water say London needs it because population growth and climate change have overwhelmed its 150 year old sewers. After storms and heavy rain, excess water overloads the system and combined untreated and semi-treated sewage and rainwater discharges into the river and streets.
Professor Charles Binnie who chaired the Thames Water and government team that recommended the project a decade ago, says 鈥渢echnology has moved on,鈥� and smaller improvements and green infrastructure alternatives such as SUDS and green roofs on buildings would work just as well in stopping rainwater from overwhelming the sewage system.
What affects London today, will affect the rest of us tomorrow. We鈥檝e paved over much of our urban landscape and reduced natural drainage where rain can drain in a controlled and sustainable way.
We need to change how we build and manage water in new and existing buildings and we need more integrated drainage at every stage to cope with more storms and increased rainfall.
From rain to drain, we need simpler solutions, joined up thinking and support for all levels of the supply chain 鈥� merchants, specifiers, property managers and builders 鈥� to avoid spending well over the odds, like London鈥檚 super sewer, because we鈥檝e run out of time and options.
Steve Durdant-Hollamby is managing director of Alumasc Water Management Solutions
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