Right now the Green Garage is literally surrounded by cement, except for the tiny 9-ft wide backyard. So when it rains, all of the rain goes to our storm sewers. Our goal, however, is to return 100% of the water back to the land. The reason: storm sewers often overflow, causing the storm water to mix with sewage water, and this mixture returns to our lakes. Not a good thing. So we want our water to get back into the ground where it belongs and out of the sewers.
So how much water goes into the sewers right now? We have a water group studying this very issue, and here’s what they have come up with: FOR EVERY INCH OF RAIN, OUR ROOF DUMPS OVER 7,000 GALLONS OF WATER ONTO THE GROUND AND INTO THE SEWERS. Yep, that’s 7,000 gallons. Our building is 11,000 square feet, in case you’re wondering.
So we have a problem. That’s a lot of water. We have a couple of solutions in the works right now. First, we are turning our alley into a green alley — at least 50% permeable – with gardens bordering the edges and permeable pavers lining the bricks and small pieces of concrete. The gardens will absorb most of the water in the alley. Cement will be removed from the front the the building also, and gardens will once again provide a home for the rain. Even our parking lot will be lined with gravel, allowing the water to penetrate.
We are still concerned absorption rates, however. One idea we’ve got: some gutters could feed into 12″ tubes with small holes. The tubes would be buried several feet below the ground and surrounded by 2-3 feet of gravel. The water would travel through the tubes, seep out the holes and into the gravel, which would increase its absorption into the ground.
So that’s our rainwater story so far…..more to come.