Shortchanging Stormwater Mangement

On the PI's environmental blog today, they report that the Puget Sound Partnership's members have acknowledged that stormwater issues have not been adequately addressed in their draft plan. For urban environments like Seattle, the problem is two-fold: quantity and quality.

In the natural system of the Pacific Northwest, our natural systems absorb 90% plus of all stormwater that hits the ground so that runoff only happens with a small percentage of the rain. Rich layers of duff and humus, evergreen needles, complex multisurface leaves and bark all help absorb that water.

Of course, in urban environments, we are not so lucky. Almost 100% of our stormwater hits the ground and runs into pipes which are either 1) flow directly into our streams or 2) go to West Point for treatment (unless there is too much water, in which case it is sent, untreated into the Sound).

So what are we to do. The biggest bang for the buck is likely to be trees along riparian corridors. They not only control the quantity of water being discharged, but they also improve the quality of the water by removing pollutants and cooling the temperature which is good for salmon.

But there are also upland elements that need to be addressed as well. Green roofs, green walls, swales, natural drainage systems .. . all of these elements help improve stormwater runoff which, in aggregate, make the Sound that much more healthy.