Just north of the Houlihan Bridge a large portion of a river island that for years was a wasteland of dredge spoils and invasive species is being revitalized.
The U.S. Army Corps of Engineers pumped dredged materials on this piece of Onslow Island for about 25 years, until 1999 when the island couldn’t accept any more. Then, last year, the corps and the U.S. Fish & Wildlife Service, which owns the land as part of the Savannah National Wildlife Refuge, hatched a plan to put it back in use for dredging and for wildlife.
Now, 93 acres of invasive plants such as Chinese tallow have been cleared and nearly two miles of earthen [filtered word] surround two side-by-side impoundments. Nutrient-rich mud from the river bottom will be pumped into the western impoundment. Excess water will flow through a weir into the eastern impoundment.
The flow of dredge materials will encourage the growth of invertebrates such as midges that are like candy for shorebirds such as plovers, avocets and black-necked stilts, said refuge manager Russ Webb. Eventually, there will be mud flats, shallow water and deepwater areas for a variety of waterbirds, though the impoundments were still dry at the dedication Tuesday.
“It may not look like a typical refuge yet, but it will soon be teeming with wildlife,” said the Col. Thomas Tickner, commander of the corps’ Savannah District.
The improvements are a joint effort of the Savannah District of the U.S. Army Corps of Engineers, the Fish and Wildlife Service’s Savannah National Wildlife Refuge and the Georgia Department of Transportation. DOT provided 35 percent of the funding for the $2.6 million project.
The project is expected to pay for itself in its first year of operation. The savings come from the site’s proximity to upper harbor dredging, which precludes the need to transport the dredge materials eight to 11 miles downstream to the next closest spoils site in Jasper County. The dredge containment area holds up to 660,000 cubic yards of material.
The project is connected with ongoing maintenance dredging rather than harbor deepening.
Onslow’s bird habitat will eventually be open to the public for wildlife viewing. Plans include a biking and walking trail and possibly an observation tower. However, it will be closed during periods of active routine maintenance dredging.
More details will become available once the project becomes active, Webb said.