More than 2,000 acres of Lake Bistineau are currently covered by the ever-invasive aquatic weed giant salvina.
As biologists with the Louisiana Department of Wildlife and Fisheries are predicting the weed to continuously multiply atop the waters of the 17,000-acre lake throughout the remainder of the summer, the dam gates of the lake will open next month.
Much of the infestation is confined to coves and tree-filled areas north of the state park, according to LDWF officials.
Officials will open the dam gates on August 4, drawing the lake down four to six inches per day until the maximum level of seven feet below pool stage. The gates will be closed no later than December 1 to allow the lake to refill.
Giant salvinia is native to Brazil and was introduced to the United States as an ornamental aquatic plant. It spreads to new water bodies mainly by unintentional means on boats, fishing and water sports gear.
The plant can double its numbers in as little as two days. It collects into a dense, floating mat, cutting off light to other plants and reducing oxygen content in the water degrading water quality for fish and other organisms. Alone and especially combined with alligator weed, also common on Lake Bistineau, salvinia can make waterways unnavigable.
For nearly 10 years, officials have battled salvinia on Lake Bistineau through drawdowns and spraying. Biologists are currently researching organic means of control, such as weevils.
Any sale, transport or release of salvinia is prohibited by federal law.
During the upcoming drawdown, about 8,000 acres of water will remain for boaters. However, LDWF officials advise caution as channels will be much shallower limiting clearance of underwater obstructions.
Boaters will be able to access the lake from the Port of Bistineau launch on the east side of Webster Parish, the Bossier public launch on the lake's west side, Grice's on the southeast side of lake at the dam and Bayou Dorcheat public launch on the north side of lake on Louisiana Highway 164 in Webster Parish.