Floating Islands Clean the Waters at Broadlands

A previously unremarkable stormwater pond at the end of a Broadlands cul-de-sac is slowly turning into a lush, shaded pool, and a microcosm of nature surrounded by development.

In the middle of Burnt Hickory pond are islands with nothing below the surface but dangling roots and cables to hold them in place. With the help of those floating islands, natural growth at the banks of the pond, and hardworking volunteers, the pond’s water is being cleaned with the same natural processes that would have cleaned a pond on that spot before homes and shopping centers sprouted up.

Stormwater ponds have been a part of managing rainfall and preventing flooding for years, but the ponds dug to collect that water can become polluted and unhealthy. Water carrying fertilizer, pesticides, and other runoff from driveways, roads and grassy yards collects and is concentrated in these ponds. They often lack the natural ecologies that would filter that water before it finds its way into the streams, rivers, and bays, and grassy yards do very little to absorb water or clean it.

But the Broadland Homeowners Association, with help from volunteers, the Piedmont Environmental Council, the county government, and a grant from the National Fish and Wildlife Foundation, is changing that at Burnt Hickory pond.

The roots of the plants on the floating island reach down into the water, getting all the sustenance they need from the nutrients mixed in the water, cleaning it in the process. Around the banks of the pond, native species have been planted to form a green buffer around the pond.

Broadlands HOA General Manager Sarah Gerstein said the project has been going for a year and a half, and it’s still growing in.

“You can sort of equate it to like if you’re a woman and you’re trying to grow out your bangs,” she joked. “When they’re nice and cut they look good, and when they’re long they look good, but in that in between phase they just don’t quite have the look you’re going for.”

But she says the project shows promise, and that “patience is key.”

The Broadlands HOA, Loudoun County, and Piedmont Environmental Council are trying out a floating island, seen here in the middle of a stormwater pond, to improve water quality. The lines across the pond are to keep geese from nesting on the pond. [Douglas Graham/Loudoun Now]
            It hasn’t all been easy. It’s been a challenge to get the native plants at the pond’s edge established, and a miscommunication with a county maintenance crew meant they accidentally mowed down that buffer.

The volunteers’ efforts are not helped by the Virginia Department of Transportation, which for years has planted an invasive Asian plant, sericea lespedeza or Chinese bushclover, for erosion control along banks and roadways. According to the National Park Service, the species was introduced to the U.S. in the 1800s by federal and state agencies. The park service advises against planting it, and recommends a number of native alternatives.

Lespedeza has found its way into other plantings, forage for livestock, and the banks of Burnt Hickory pond, where it is outcompeting native species.

“We can’t spray it, because it’s right by the water,” said Oya Simpson, Broadlands Wildlife Habitats Committee chairwoman, Piedmont Environmental Council community outreach projects specialist, and Broadlands resident. “We can’t easily mow it down, it’s going to grow back.” She said there have been discussions about a controlled burn, but that would put the plant buffer around the banks of the pond back to square one.

And the volunteers who put in the islands didn’t reckon on one force of nature: Geese.

Geese, as migratory birds, are protected, so they can’t be forced off the pond once they’re there. Discouraging them from climbing onto the island and eating its plants has proved a test of ingenuity and will.

“We didn’t understand enough about goose behavior,” said Piedmont Environmental Council member Gem Bingol, who helped plant the islands. First, she tried putting up a barricade to keep geese from landing on the island—but instead the geese landed in the water and climbed onto the island. A chicken wire fence was put up, and the geese pushed it down. Netting was put over the entire pond, but the geese can also land near the banks and walk in.

Gem Bingol of the Piedmont Environmental Council helps install stakes on a floating island in the middle of Burnt Hickory Pond at Broadlands to try to keep the geese off. This particular scheme did not deter the geese. [Oya Simpson]
            “Nothing has given me an appreciation for their fortitude like this project,” Bingol said.

Ultimately, the solution was a mix—the wires over the pond, which keep the geese from flying in, and thick vegetation around the banks, which the geese avoid for fear of predators.

“Everything’s connected, really,” Bingol said. “That’s what you discover doing this work.”

“It was sort of a pilot project for us out there,” said Loudoun Environmental Program and Policy Administrator Alan Brewer. “The technology is there, the science is behind it, it will work, but with anything you know you have to see. … In a lab you really don’t have geese coming in and sitting on your study bench and eating your plants.”

Simpson, who checks on the pond regularly, can’t help but think about what could have been if the plantings around the edges of the pond had been there since the beginning.

“The biggest sort of question in my head is, why it is not as successful as it could be, and the answer is simple: if this was a practice that was done when they were installing these stormwater ponds … it could have been much easier, cheaper, and successful,” Simpson said. She said by now, the pond could be a beautiful, shaded spot.

“When I drive around and I see the ponds that are mowed down all the way, which is very, very groomed, to me it looks more like a hole with water in it,” Simpson said. Instead, eventually, the Burnt Hickory pond will be good not only for water quality, wildlife, and the watershed, but for the people whose houses have a view of the pond.

“The idea is there,” Simpson said. “And I think there are only benefits that we will have as a community to do these things, and do it right, do it from the beginning.”

rgreene@loudounnow.com

One thought on “Floating Islands Clean the Waters at Broadlands

  • 2017-08-31 at 6:55 pm
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    Maybe the answer to the sericea lespedeza was some sheep! Shepherds value this plant because the tannins it contains suppresses blood-sucking internal parasites of sheep. Auburn University has done considerable research on this species. Urban Shepherds has been working with local communities to use sheep to improve the ecology of urban areas by grazing sheep–which make meat and fiber from biomass, instead of using internal combustion engines to mow it down.

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