Sunday, October 11, 2009
First Flush......Time For Action!
In a couple days the Bay Area is scheduled to see a significant amount of much needed rainfall. I for one will have a few containers out for rainwater collection as, many of my plants, orchids in particular, seem to prefer pure rainwater instead of city water. But my first course of action will be to take care of a few simple tasks before the rains come.
First flush is the term given to stormwater from the first rain that dislodges pollutants from the ground surface i.e. driveways, sidewalks, roads, etc. This stormwater typically carries with it a higher initial contaminant load and is a major source to the pollutants in our creeks, rivers, bays and oceans. There are ways to minimize the pollutant levels ordinarily found in a first flush event and strategies to control the stormwater runoff in order to reduce the effects on the environment.
There are steps you can do at home to minimize pollutant levels. Analyze the area and judge what possible effect rainfall will have on that area. If your are still using chemical fertilizers, sweep up any granules from the impervious driveway and sidewalk to minimize the opportunity that it gets washed down the stormdrain. Oil spots in your driveway, parking stall or street in front of your house should be soaked up with kitty litter and disposed of properly. It may be necessary to sweep the street gutter free of debris, leaves or soils. Anything you may think of that does not belong in our watershed, find a way of preventing it from going there.
Controlling stormwater runoff can be a more difficult and in-depth solution requiring planning and technical knowledge. Collection, treatment, and discharge systems can be part of the solution to handling stormwater runoff. My preference is to work with nature and create vegetative bioswales to collect, treat and discharge stormwater. The swales are both an eye pleasing landscaped solution and functional in stormwater runoff mitigation. I enjoy designing them for parkways in place of the useless lawn between the street and sidewalk.