The Chesapeake Bay Foundation has a new idea for saving the bay: Install floating, fertilizer-sipping wetlands in Virginia’s small lakes and storm water ponds.
by James A. Bacon
The Lewis Ginter Botanical Garden is well known in the Richmond region for its Fountain Garden, its Rose Garden, its East Asia Garden and its Wetlands Garden. Its newest addition could well be referred to as its Floating Garden.
Working in conjunction with the Chesapeake Bay Foundation (CFB) last week, 20 volunteers loaded a large, plastic-mesh raft with perennial plants, lugged it down to Lewis Ginter’s Lake Sydnor, maneuvered it into open water and anchored it into place with cinderblocks.
A small crowd gathered to observe the proceedings. “When we launched the island,” says Ann Jurczyk, outreach and advocacy manager for the CFB, “people standing on the bridges started applauding when they saw it wasn’t going to sink!”
The floating garden, which measures a mere 120-square-feet, may qualify as the smallest attraction in Lewis Ginter’s 50-acre park of exquisitely tended trees, shrubs and flowers. But the plant-laden ark fulfills a critical function: removing fertilizer from the lake.
“The island functions like marsh plants,” explains Grace Chapman, Lewis Ginter’s director of horticulture. Roots grow through the mesh and dangle a foot or so into the water, where they absorb run-off nitrogen and phosphorous that feed the algae blooms and create oxygen dead zones. But treating the scourge of Virginia’s waterways is not the only thing the island does, she says. “It makes a great turtle barge.” At last count, the island had eight turtles.
Lewis Ginter’s floating wetland is one of two launched May 15 as part of a larger initiative to clean up Upham Brook. Restoration of the badly impared urban stream, which feeds into the Chickahominy River, is a top priority for the CFB. The same day saw the launch of a second floating wetland at the nearby Belmont Golf Course. A grant from a statewide restoration fund, financed by the purchase of Chesapeake Bay license plates, paid for the installations.
The idea for floating wetlands originated about a decade ago out West and has drifted east. Floating Island Southeast, based in Chapel Hill, N.C., is the exclusive provider of “BioHaven Islands” in Virginia and the Carolinas. The purchase price runs under $4,000 per island, including plants and shipping, says Jurczyk.
The Environmental Protection Agency has not yet vouched for the efficacy of the floating islands but a number of small-scale studies, including one conducted by Virginia Tech, has shown positive results. Floating Island Southeast claims that one square foot of its buoyant botanicals will suck up 10 grams of nitrate, 15 grams of ammonia and 0.5 grams of phosphate per day.
Lewis Ginter’s floating wetland is doubly important to CFB, says Jurczyk, because many people will see it, learn about it and hopefully grasp the potential to install one in their own neighborhood. Especially well suited for storm water retention ponds, the floating islands are readily installed and easily maintained. “The nitrogen and phosphorous [removed] is pretty remarkable on a cost-per-pound basis,” she says.
The CFB is looking for a home for two more islands, which it is willing to install at no cost. The main commitment it seeks from a partner like a golf course or homeowners association is to pull in the island once a year and weed out invasive species. Says Jurczyk: “This is a pretty good investment to keep pond health where it should be.”
This article was made possible by a Bon Secours of Virginia Health System sponsorship.