Lake Bistineau October 20, 2009 Update

 

Lake levels are still on the rise as a result of heavy rainfall during the last few weeks. Therefore, the drawdown to seven feet below pool stage is behind schedule. The goal of the drawdown is to strand the salvinia plants in the lake, but high water levels have allowed the plants to spread into areas that typically do not have water.

The increased rainfall has however caused the salvinia to move, and many acres once covered with giant salvinia have passed over the spillway or through the water control structure. Most of the plants are piling up behind the water control structure on Loggy Bayou Management Area.

Once the lake is down, department staff will further inspect the area. The information gathered will be used in developing a long-term plan for the lake. Efforts will focus on areas showing little response to the drawdown and potential causes for the lack of response. Many of these areas harbor salvinia and become nurseries for the plant.

Excavation and tree removal may be necessary in order lower water levels in these areas. If so, standard procedure will require us to obtain a U.S. Army Corps of Engineers permit. For those areas on private property, an executed agreement will be required.

Despite delaying the drawdown, the high water event does create a positive in this instance. The effects of the seven foot drawdown will be more significant than if the lake was at its normal stage.

We have yet to determine when the gates will be closed. Many factors will play into this decision. We are interested in doing some modifications to the spillway and lake bottom. Some of this work will require the lake bed to be bone dry. Other considerations include permits, MOUs, advertisement for bids, contracts, partnerships and funding. There is a possibility that the lake will be left down for another year or longer.

Mark McElroy
Fisheries Biologist