Will we ever see “Sponge Cities” in the UK?

Flooding continues to be a major problem worldwide as our population continues to grow. In the UK, Government advisors are still suggesting that homes and offices be built on flood plains in spite of the risks – so it would seem that the problem can only get worse..

The Chinese have particular difficulties with huge numbers of people leaving the land to work in cities which are expanding at an ever increasing rate. With it comes the problem of channelling rainwater to minimise flood risks.

Their answer - to create “Sponge Cities” and they reckon that in time, 80% of urban areas should absorb and re-use at least 70% of rainwater. The objective is to reduce the intensity of rainwater runoff by enhancing and distributing absorption capacities more evenly across targeted areas.

Measures include rooftops covered by plants or green roofs which are becoming increasingly common across Europe, scenic wetlands for rainwater storage, and permeable pavements that store excess runoff water and allow evaporation.

While all these ideas sound good in principle there is already mounting evidence that no one really wants to spend the money needed to create “Sponge Cities” and any such initiatives also have to go hand in hand with reducing carbon emissions and protecting the environment.

You cannot for example chop down natural sponges such as woodland to make way for new homes and offices and there is a limit to what even a sponge can soak up. In other parts of the world innovative water initiatives have been adopted  such as wetland restoration in the American Midwest, flushing systems using collected rooftop water water have been introduced in Oregon USA, bioswales in Singapore, and public spaces as flexible water retention facilities in the Netherlands.

In the UK there seems to be little joined up thinking with “Sponge Cities” way off the radar. We are seeing a steady increase in green roofs and seemingly token work on sea defences – but that seems to be it

Perhaps we are being a little unfair on our Government – but how long before the next big flood and when the debate starts all over again?

By John Ridgeway