So back on the 9th of February, I believe I promised you how we could solve a few of the ills of parking lots and their rather catastrophic levels of runoff. Well, look no further, wanderers, for the answer is a simple one: use smart design to let nature do all the work for you for free!
The concept is very simple, as shown by this diagram.
You dig a hole. Install a pipe that is an underdrain for excess. Dump in some gravel, some nice sandy/loamy stuff on top of that that drains well. Then plant some native plants that like living in soggy places. Voila! Lovely stormwater control that filters AND drains water far better and much more prettily than any conventional engineered solution!
We are all used to the stupid useless landscaped islands that are standard issue for parking lots -- some pine straw or mulch with a thirsty looking tree or some scruffy bushes sitting there. They are usually elevated above the lot surface and mounded so that little if any water is actually absorbed by plants and soil. Each one a collassal waste of time and money.
You can easily and cheaply install a raingarden in the place of each of these during initial construction or retrofit later. Key elements: (1) The elevation of the soil surface must be slightly lower than the lot itself. (2) Vegetation must be appropriate for wet environments so it doesn't drown. (3) Curbs must be notched to allow water entry into each patch of raingarden. To the right is a great example of parking lot application.So why aren't these already all over the place if they are so easy?? Simple: developers and engineers seem to be rabidly afraid of change, even when it saves them money and looks better. The train of thought appears to be that the way things must be done is the way they have been done for the past 30 or 40 years. But you don't have to stand for this. Call or email your local government, city planner, county commissioner and ask that these raingardens be required in all new development. They are an effective and beautiful addition to residential lots too; you can easily add one to your own yard, let your creativity run wild and set an example for your community. Wouldn't you love to have this beautiful garden in your yard? I sure would!
2 comments:
I am stunned by the simplicity of the rain garden design. In fact I have a drainage highway that runs through my backyard into the neighbors lower back yard. I am so inspired by this I'm going to put one of these in this spring. I have been pining for a wetland garden.
You should! There are so many neat plants you can put in and a TON of resources online to build one. Just google "raingarden" and you'll find so much information you won't know what to do with it all! If you've ever been to our HQ building on Centennial campus NCSU, all the landscaping between the building and parking deck is one huge raingarden.