Thursday, 7 August 2008

Permeable Pavement and Proliferating Plants: Fighting Floods, City Heat and Mitigating Climate Change All at Once

Much talk here these days about soil absorption, drainage and run off from pavement. The rain keeps falling, and flooding continues in many areas. Part of this is due to unusually high rainfall this summer, following a winter of heavy snow which means that the soil is saturated. But part of the problem comes from increased building and paving over of areas which formerly slowly absorbed rainwater.

Just last week the city of Montreal announced plans to encourage the greening of asphalted areas in order to cut down on creating heat islands in the city. This same sort of effort can reduce excessive run-off, it seems. Trees and shrubs not only soak up rain water, their leaves slow the speed with which rain reaches the soil, decreasing the chance of flash flooding. Similarly green roofs can use and/or retain rainwater, reducing run off.

My mother always said that building a house on a swamp didn’t make the swamp any less a swamp, and I agree that people and developers who knowingly build in floodable and landslide-prone areas don’t deserve much sympathy. Similarly, we should recognize that what we’ve been doing to the planet will have effects on the climate and weather patterns. Straightening this out will take society-wide, world-embracing action. But there are also many smaller things that we ought to do to counter act what we’ve done.

Replacing asphalt paving with interlocked bricks is one since water can seep between the blocks to be absorbed slowly. (Click here for more information.) More planting everywhere is also surely on the agenda. Maintaining trees and other greener is not a frill but something that all citizens and governments should do. It all is just another example of the need to think globally and act locally.

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