Scum sucking plants save ponds

Ponds here, ponds there, ponds are everywhere on the Grand Strand. Stormwater experts say there are some 14,000 retention ponds dotting South Carolina's coastal plain.

The ponds aren't just pretty. They exist for the purpose of capturing stormwater runoff from driveways and parking lots that would otherwise swamp people's backyards.

"Rather than have that just flush out into the stream and go down and flood somebody downstream, these are designed to capture the runoff in a holding bay essentially," said Dave Fuss, a watershed planner with Horry County Stormwater Management.

But Fuss said if the ponds aren't properly maintained, they can quickly become overrun with smelly, unsightly scum.

So Fuss and other officials from Horry County's stormwater department held a demonstration Thursday to instruct local homeowners associations on how to build floating wetlands that can help rid a pond of algae.

A floating wetland is a plastic foam grid that's filled with native plants like swamp hibiscus and water willows. The plant-filled island sucks up so much of the nourishment in the water that it prevents algae from taking over a pond.

"It'll compete for those same nutrients, so instead of having these huge mats of algae, you'll be growing nice plants," Fuss explained.

The floating wetland may have an environmental purpose in keeping a pond healthy, but many of the homeowners who attended Thursday's demonstration like the idea of a plant island mostly because it's more attractive than a pond full of scum.

"This is something that'll be beautiful once it's gets established and still serve a good purpose," said Joanne Meccia, who lives near a retention pond in the Harbor Lights community in Surfside Beach.

A floating wetland can provide habitat for some wildlife species and prevent the loss of others. Fuss said algae can so thoroughly overtake a pond that it causes fish kills.

"That can happen because it just eats up all the oxygen overnight and there's none available for those fish."

Fuss said over time, the plants on the floating wetland fill out, covering up the foam grid and leaving the appearance of an island of leaves and blooms - a beautiful alternative to a scummy pond.

He said the floating islands cost about $1,000 each, for the plastic grid, plants and delivery. Suppliers include Charleston Aquatic Nurseries in Johns Island, SC and Floating Island Southeast in Chapel Hill, NC.