My name is Mary. I’m an aging person with an aging house. I’m going to tell the story of transforming my house from something I don’t want into something I do...
Since the first of this year, Arlington has a new requirement for home builders: Either A: Take measures to control runoff from roofs and pavement or B: Pay a fee. I don’t like paying fees and, besides, I am upset by the amount of debris and volume of water that erodes the stream beds on its torrential way to the Potomac after a big storm. So I’m going along with plan A.
I decided to calculate how many gallons of runoff would be produced by my property in the occasional six-inch downpour. I’ll have about 1,425 square feet of roof, which will generate 712.5 cubic feet of water. There are about 7.5 gallons of water in a cubic foot, so the runoff would amount to about 5,343.75 gallons of water. Even smaller storms can produce enough runoff to overwhelm the storm sewers and the streams.
I grew up with cisterns for water. Rats periodically died in there trying to get a drink, so we filtered and boiled the water before drinking it. But even then, it had a foul taste. We were so frugal with our water, we were admonished only to flush after “major occasions,” which, after a sip or two of our cistern water, happened very frequently.
Still, I am committed to the idea of cisterns, if not for drinking water, at least for irrigation. I’d like to have one of those at the downhill side of each of the two main gutters. They’ll be a major contribution to my garden, as well as a way to reduce the runoff that gushes into the small stream downhill.
Arlington County will give me credit for the cisterns, but I still have to take precautions to minimize the rest of the water, as well as to cope with whatever overflows out of the cisterns. Jack Sheele is my engineer. He specializes in water management and has advised me to plan for a rain garden.
A rain garden should ideally have very well-drained soil that extends as deep as possible. It acts like a sponge when a lot of water is funneled into it. Rain gardens do not take care of the torrents, but at least they help a little bit. Christin Jolicoeur is Arlington County’s authority on rain gardens and she can be a resource for anyone wanting to build one. People can visit either the Arlington County or the Northern Virginia Regional Commission Web site to find out what rain gardens are all about and what resources and incentives there might be to develop a good rain garden.
While I was looking around for an example of a rain garden to photograph for the blog, I went to Potomac Overlook Regional Park. It was raining and no one was there except someone who was building a garden gate.
I asked him whether he knew anything about a rain garden and he took me instead to his own personal project: a system of vernal pools.
A vernal pool, he explained, is a small pond that holds snow melt or spring rains and becomes a habitat for amphibians and sometimes tiny fish. The water holds a slurry of decomposing vegetation. Sometimes they might get dry, but they are encouraged to stay wet by having an impermeable lining, either hardpacked clay, or, in the case of the vernal pools at Potomac Overlook Regional Park, plastic. Kiddie pools work very well.
Sure enough, in the pools were zillions of the little guys all waiting to grow legs and hop out. And some bull frog tadpoles that are not such little guys.
My guide was Jamie Marcey, a Yorktown senior working toward his Eagle Scout rank. He has been working on this project all spring and tending to his vernal pools while monitoring the multitude of amphibian life that have taken up residence in them.
My quest for an example of a rain garden may have failed, but I struck a gold mine of other ideas for the area beyond my property line where the land descends into a ravine.
When I got home, my dogs and I went to investigate the spring below my house and the storm water detention pond that control the runoff from the Palisades Town House development.
Could either of these become a vernal pool? There were no tadpoles in any of the pools I saw, but could I do something to encourage them?
The downside might be mosquito breeding, but, as Jamie pointed out, the frogs and salamanders will consume huge amounts of mosquito larvae.
So now I’m waiting for Arlington’s environmental services department to look at Jack Sheele’s plan and finally give us the demolition permit.
Previously: Struggles with the gas company