By 2100 High Wycombe will be a much drier place than it is today. Which makes it ironic that one of the effects of Climate Change HERE will be to vastly increase the probability of flash flooding. Remember WHERE you read these words first.
The United Kingdom Climate Projections was published in June 2009 and is the most comprehensive report of its kind ever produced. It shows that in the UK we face warmer, wetter winters and hotter, drier summers, with more drought, more intense heat waves and flash flooding. In future, rainfall could significantly decrease in the summer (particularly in the south east) and significantly increase in the winter (particularly in the north west). Heavier winter rainfall is expected to become more frequent.
In June 2007 Sir David King told a committee of MPs that the most serious impact in Britain would be flash floods: “The Victorians left us with a drainage infrastructure that is good for soft rain, but with torrential down pours it can’t cope.” In June 2010 at least 15 people died when “unprecedented” flash-flooding hit parts of south-eastern France, submerging streets, sweeping away cars and forcing people to take refuge on the roofs of their houses. In the worst flooding the region saw since 1827, authorities struggled to cope with the speed at which water levels rose. “In 24 hours, we had 350mm of water,” said local official Olivier de Mazière. Local official Corinne Orzechowski spoke of “a devastated town centre, extremely battered, with car wrecks in the streets, roads that have fallen in, houses ripped open, infrastructure damaged”. The majority of casualties are thought to have died while trapped in their cars.
Lets make something very clear about High Wycombe: it is a town the sprawls up the sides of seven hills. Most of us live in areas that are quite steep. Walk around Wycombe as I have. Look at what people have done to their front gardens. Take a walk down the Totteridge Road – do you see cars parked on lawns? No. You see concrete, tarmac and block-paving. These won’t absorb a heavy rainfall quickly in case of deluge. When the heavy rain comes (and it will) gardens, homes & lives will be washed away. That will give the Bucks Free Press something to report that will be more important than the Stadium saga.
Believe me you are going to hear a lot more about flash-flooding in the next few years. The Transition Town High Wycombe web site wrote a scenario which envisioned disastrous flash flooding for the town before 2020. We wrote that prediction in 2009. You could have knocked me down with a feather in 2010 when I heard a Council Officer tell me she had been tasked with assessing the risk. How soon will it be before emergency services are being drilled on rescue procedures involving houses being washed away? Do such scenarios exist within local contingency plans?
Enter a new phrase you may be hearing a lot more often: “SUDS” = Sustainable Urban Drainage Systems. Urban sewers have not been built to cope with heavy rainfall. The situation is made worse when heavy rain falls after long periods of drought. Since the soil is baked hard it shrugs off water it would otherwise soak up. All those hard surfaces will need replacing with permeable ones. This is SUDS and it will enter our lexicon via the Planning Department. They may require SUDS for every new-build in the town. So forget the annual debate about road repairs. This will seem trivial. We will likely see town centre parking charges go up dramatically to pay for highways work involving SUDS upgrades. Expect howls of derision from drivers in the pages of the Bucks Free Press!
Other than SUDS we may expect to see green roofs becoming popular. Tree planting will also mitigate the risks. So expect the roofscapes and landscapes of High Wycombe town to become somewhat greener. And when we say “greener” this isn’t some lifestyle choice. It will be a bit of common-sense engineering that might just save life and property for years to come. And remember: during the next rainstorm, get out of your car.