Officials with the Louisiana Department of Wildlife and Fisheries say while the 2016 drawdown was a success, it didn’t work nearly as well as it should have.
Jeff Sibley, biologist manager for Region 1, said about 1,800 acres of salvinia remain on the lake.
“The salvinia was reduced by about 4,500 acres,” he said. “That was considered a success, but this time of year for us to have that much salvinia on the lake, it’s much more than we typically have.”
The acreage left following a drawdown is typically 300 to 700 acres, he said.
In the last two years, Lake Bistineau has been plagued with mild winters, which has contributed to the growth of the salvinia. Sibley said biologists are already seeing new buds of growth, which compounds the problem.
The drawdown this past year was delayed by three weeks, and LDWF officials argued that delaying it would decrease the drying out time usually afforded during the hottest and driest part of the summer.
Another benefit to the drawdown has been the drying out of organic materials at the bottom of the lake, thereby speeding up the decomposition process, he said.
Next week, LDWF will begin spraying herbicide to hinder its growth, but Mother Nature will also have to lend a helping hand. An earlier than normal drawdown may be likely, Sibley said.
“Unless something changes in nature, based on our past herbicide applications, we may be looking at a drawdown earlier than we normally do, but that’s yet to be determined,” he said.
A number of factors will play into the plan of attack on the invasive aquatic weed, including rain, water depth – enough to begin flushing the plant out of the lake, or cold weather events.
As of Jan. 25, Sibley said the lake has now come back up to pool stage and is flowing over the spillway.
A meeting is planned for 6:30 p.m., Tuesday, Feb. 21, at the LDWF Region 1 Office in Minden to discuss the salvinia and what the tentative plan might be moving forward.