When it rains cities should hold all the water. In the 20th century that idea would have been laughed out of the room; today, we know better. Urban water management is vital to a healthy city, ecosystem, and flood mediation. The old idea of building giant channels of concrete to force water out of their natural areas (the best example of this is in L.A.) is thankfully being replaced with better ideas.
One of those better water management ideas is to just soak it all up. Make the city a sponge.
It tries to do it in three areas. The first is at the source, where just like a sponge with many holes, a city tries to contain water with many ponds.
The second is through the flow, where instead of trying to channel water away quickly in straight lines, meandering rivers with vegetation or wetlands slow water down – just like in the creek that saved his life.
This has the added benefit of creating green spaces, parks and animal habitats, and purifying the surface run-off with plants removing polluting toxins and nutrients.
The third is the sink, where the water empties out to a river, lake or sea. Prof Yu advocates relinquishing this land and avoiding construction in low-lying areas. “You cannot fight the water, you have to let it go,” he says.