Who’ll stop the rain?
Special gardens provide a way to absorb storm-water runoff and limit pollution reaching waterways
Nobody likes it when Mother Nature rains on a perfectly planned day, but when it rains on your rain garden and the water filters seamlessly back into the ground, that’s just nature’s way.
With that in mind, officials in several communities, including Franklin, Wellesley, and Concord, are ramping up their efforts to install rain gardens as a way to help control storm runoff. Lined with special soil and planted with perennials and grasses that can withstand both wet and dry conditions, the rain gardens are designed to absorb and filter water carried from areas with impervious surfaces.
According to the Charles River Watershed Association, Massachusetts receives about 45 inches of precipitation each year. In a natural environment, nearly half of the rainfall would be absorbed into the ground; almost all of the rest would return to the sky as water vapor.
However, with roads, driveways, parking lots and buildings covering significant portions o the landscape, and with fewer trees to turn the water into vapor, more than half of the rainfall in a typical year turns into storm-water runoff, picking up pollutants while flowing over impervious surfaces on its way to storm drains, wetlands, rivers, and lakes.
Some communities have already incorporated rain gardens into public spaces, and require them in certain private developments. Now, they’re hoping homeowners will get into the gardening game.
Franklin is holding a free training session Saturday, starting at 10 a.m. at the Department of Public Works administration building on Fisher Street, to demonstrate how residents can install rain gardens on their own properties.
“The idea is not only to educate people about the benefits of putting these kinds of rain gardens on their properties, but also provide them with resources they could use themselves to implement them,” said Pallavi Kalia Mande, director of the regional watershed association’s Blue Cities program.
The program received a $16,000 grant from the federal Environmental Protection Agency toward storm-water treatment systems that result in the direct removal of phosphorous from runoff. An abundance of phosphorous can damage the ecosystems in waterways by nurturing plant growth until it chokes out other life.
Franklin has built several rain gardens on public property, including at Gerald M. Parmenter Elementary School, Fletcher Field, and the upper parking lot at the commuter rail station in the center of town.
“We like to use them as an educational tool,” said Kate Sjoberg, Franklin’s manager of geographic information systems, who has been working with the watershed association on the initiative. “They teach students and teachers about runoff, and what we’re trying to do to prevent pollution.”
In addition, Sjoberg said, “whenever we do new road construction, we try to put in a rain garden to reduce runoff on impervious surfaces.”
In encouraging residential rain gardens, the town is offering free soil, mulch, and stones to landscape the area, as well as pipes to transport rainwater from downspouts to the garden; homeowners must purchase their own plants.
Other local communities that have installed rain gardens on public property are now urging them on residential properties as well.
In Wellesley, among other efforts to mitigate harmful runoff, the town three years ago created a small rain garden at Morses Pond between the bathhouse and the beach area, as a pilot project to encourage residents to install their own. Last summer, the town also established a rain garden at Town Hall next to the duck pond.
And it doesn’t stop there: Wellesley’s Town Meeting earlier this month approved $5.5 million toward restoration efforts at Fuller Brook Park, work that will include the creation of two large rain gardens, said Janet Bowser, executive director of the town’s Natural Resources Commission.
“In a lot of cases, it’s less expensive and less intrusive” than managing runoff via an “out of sight, out of mind” underground chamber that requires maintenance, Bowser said. With rain gardens, she said, “you’re mimicking nature.”
Town officials hosted public demonstrations when the rain gardens at Morses Pond and Town Hall were unveiled, complete with an educational component and a raffle of native plants that would thrive in a residential rain garden.
In the wake of the town’s efforts, Bowser estimates that at least 10 homeowners have installed rain gardens on their own properties.
“At some point, we’d like to do a tour, or at least a self-guided tour, so people can look at these,” she said.
In Concord, efforts to retrofit municipal areas with rain gardens go back three or four years, but “residential is new this year,” said the town engineer, William Renault.
“With all of the regulatory drivers on the way, we’re trying to be proactive, be ahead of the curve, rather than try to catch up . . . and branch out to homeowners who want to help the environment,” Renault said.
The town led a tour at Junction Park in West Concord earlier this month to demonstrate the benefits of rain gardens to residents. The park hosts a bioretention system, similar to a rain garden but with a slightly different soil makeup, Renault said, for which Concord received $130,000 in grants to construct last year.
Four or five rain gardens have been installed on public property in Concord, and officials have required them in several other developments built in the past five years, including two on Bedford Street, Renault said.
For residents unaware of these gardens, the tour at Junction Park was aimed at exposing them to a wider audience.
“We thought it was a great opportunity to get the public participating in our rainwater program,” Renault said, noting that homeowners have already expressed an interest in building their own.
Officials hope the Franklin workshop next weekend sows the seeds for similar success.
“It doesn’t take rocket science to figure this stuff out,” said Mande, with the regional watershed group. “People are interested in doing what they can for the environment and helping the water quality in the Charles River, and here’s what you can do on your own property to help with that.”