By Bonnie Price Lofton
If rainwater doesn’t seep, sponge-like, into the soil around us, it runs away somewhere.
In Charlottesville, where much of the ground is covered with impermeable asphalt, it runs into stormwater drainage systems, ditches, and streams that eventually lead into the Rivanna River.
That creates two problems: first, without earth to filter and gradually release the water, the water level in the river fluctuates wildly; it’s more likely to flood during heavy storms and get too low during dry spells. Second, the rushing water sweeps along oil slicks, trash, animal feces, and lawn chemicals, bringing all those pollutants into the river we count on for both recreation and drinking water.
As a local nonprofit whose mission is to protect the watershed, the Rivanna Conservation Alliance wanted to do everything it could to manage stormwater when it moved to a new location last year, in an industrial stretch of River Road just a stone’s throw from the Rivanna. But common practices—replacing the parking lot with permeable pavement or digging a rain garden, for example—were not an option. The area was still used for heavy trucks and the ground below was potentially contaminated, as well as being in a floodplain.
A solution came in the form of the three custom-made black steel containers now in front of the nonprofit’s one-level cinderblock building, what the organization calls “essentially bioretention in a box.” Working with designer David Hirschman, of Hirschman Water & Environment, LLC, the group created a series of stormwater planters, designed to catch the rain funneled through downspouts from much of the roof and to use it to grow an array of native plants. Like a rain garden, the planters incorporate drainage and layers of stone to hold water.
“All the water that would be going into the street, and then into the stream over here,” says Hirschman, pointing out a clogged streambed, “and finally into the river…all this water now stays in the garden.”
Program Director Lisa Wittenborn says the project was built for about $12,000 (RCA did it with volunteer labor and a grant for $7,000). Pondering the no-frill businesses along River Road—Quarles Fleet Fueling, Central Virginia Rental, some car repair places—she says she’d love if her neighbors felt inspired to do similar projects. In fact, the organization, which has submitted its design for an environmental award, hopes the project will be an example of a cost-effective way for urban and industrial sites across the Rivanna watershed to manage stormwater.
Charlottesville Water Resources Specialist Dan Frisbee says multiple organizations have been working on strategies to manage stormwater, and cites Charlottesville High School as a prime example. The school built a large rainwater harvesting system that collects water from the roof of the Performing Arts Center and provides irrigation water to the practice football field. It also incorporated bioretention (essentially an engineered rain garden) to treat more than two acres of parking lot, added 6,500 square feet of permeable pavers, and converted a parking lot into a 12,500 square-foot rain garden.
Overall, Frisbee says the streams in the Rivanna watershed have not worsened over the last 15 years. Given how much land has been turned into buildings with impervious surfaces during those years, he says, that’s a victory.
For information on how to install a rain garden at home, search for “Rain Gardens” on the website of the Rivanna Stormwater Education Partnership at rivanna-stormwater.org.