This past weekend’s storm here in the Bay Area brought a second “first flush” to the Bay. It was at least six weeks since the last storm, so plenty of time for a new layer of gunk and trash to coat our streets waiting for the rain to wash it into the bay.
In a few places, the rain is now being slowed down and infiltrated back into the ground in “rain gardens” that are starting to pop up around the region as building codes require “low impact development” for new construction or grants are made available to retrofit streets. My new local Whole Foods is one example. The rain gardens there takes runoff from the surrounding streets and the parking lot and runs it through the rain gardens. before it hits the storm drain system. They work. A 2012 report by the San Francisco Estuary Institute of two projects in El Cerrito demonstrated that water quality is greatly improved as a result.
As more of these start to be built, its time to start mapping their location so we can understand how they work together. Knowing where they are going in – whether in a private garden or in a public street – is the starting point of getting strategic and intentional about where they need to be installed to improve water quality in our urban creeks and Bay.
I did a quick search and couldn’t find a resource like this for the Bay Area. A few cities, like Madison and their 1000 rain gardens challenge, have started to make some progress. Now its time for the Bay Area to step up!