Opening the floodgates......

The recent spate of weather events across the globe has sparked fresh discussions about how we approach the built environment with a view to minimising the devastation caused by storms and hurricanes.

Our capacity to deal with downpours by channelling excess water into drains is largely dictated by the ’10-year storm’ scenario. Problem is that we’re experiencing more frequent and more intense downpours – exacerbated by urbanisation – which leaves many of our towns and cities at increased risk of flooding.

In response, architects and city planners are having to look at more creative solutions that factor in the flood risk from the get-go. Schemes are being trialled that incorporate stormwater management within the cityscape and that handle excess water as a resource rather than treating it as a hazard. The city of Chicago has been at the forefront of developments, as it battles with steadily increasing annual levels of rainfall.

In the last decade, it has built over 100 ‘green alleys’, permeable pavements that enable water to drain into the ground below. It also has a two-mile long ‘sustainable streetscape’ that incorporates advanced technologies to decontaminate polluted water before filtering it into Lake Michigan.

The government in China has gone one step further by commissioning the construction of 16 ‘sponge cities’ that accommodate, rather than defend against, floodwater. Chicago architects UrbanLab have been applying lessons learned from the US to an urban development in Hunan province, creating islands around a central lake with canal-lined streets connecting the various districts.

In America’s Tri-State area where millions of people already live in a designated flood zone, plans are afoot to consider how best to protect homes as sea levels continue to rise. Proposals here include creating denser developments on higher ground, while installing elevated homes along a system of docks in wetter areas.

In areas like New Jersey, where flooding caused by Hurricane Sandy back in 2012 cost many lives and caused billions of dollars-worth of damage, a Dutch-inspired response is being considered – the restoration of wetlands and raised banks, or ‘berms’ that are designed to fill up with water during periods of heavy rain before draining out again. A pilot is already underway, thanks to government funding.

Something all these schemes have in common is the idea of working with rising water levels rather than trying – like Cnut – to stop the tide. Perhaps by using the threat of flood to stimulate more imaginative urban development, we can ultimately create cities that are more in tune with nature.