Slow water: can we tame urban floods by going with the flow?As we face increased flooding, China’s sponge cities are taking a new course. But ...Slow water: can we tame urban floods by going with the flow?
As we face increased flooding, China’s sponge cities are taking a new course. But can they steer the country away from concrete megadams?
by Erica Gies
Tue 7 Jun 2022 06.00 BST
After epic floods in India, South Africa, Germany, New York and Canada killed hundreds in the past year, droughts are now parching landscapes and wilting crops across the western US, the Horn of Africa and Iraq. The responses have included calls for higher levees, bigger drains and longer aqueducts. But these concrete interventions aimed at controlling water are failing. Climate extremes are revealing a hard truth: our development choices – urban sprawl, industrial agriculture and even the concrete infrastructure designed to control water – are exacerbating our problems. Because sooner or later, water always wins.
Water might seem malleable and cooperative, willing to flow where we direct it. But as human development expands and the climate changes, water is increasingly swamping cities or dropping to unreachable depths below farms, often making life precarious. Signs of water’s persistence abound. Supposedly vanquished waterways pop up in inconvenient places. Seasonal creeks emerging in basements are evidence that those houses encroach on buried streams, while homes built on wetlands are the first to flood.
When our attempts at control fail, we are reminded that water has its own agenda. Water finds its chosen path through a landscape, moulding it and being directed by it in turn. To reduce the impact of today’s more frequent and severe droughts and floods, a new global cohort of “water detectives” – restoration ecologists, hydrogeologists, biologists, anthropologists, urban planners, landscape architects and engineers – are asking a critical question: what does water want?