Corps to drop Pomme lake 3 feet to kill zebra mussels

The U.S. Army Corps of Engineers plans to partially drain Pomme De Terre Lake to eliminate a possible infestation of invasive zebra mussels.

The popular 7,820-acre muskie and crappie fishing lake an hour north of Springfield will be lowered by three feet to kill any zebra mussels that may have accidentally been introduced from Lake of the Ozarks. A small area of the lake also will be chemically treated.

Zebra mussels reproduce prolifically and can clog power plant water intakes, foul boat hulls, propellers and docks and disrupt local lake food chains by filtering out microscopic organisms. They can also cause painful cuts if a swimmer happens to step on their sharp shells.

"This is the first instance of zebra mussels here that we know about," said Brad Myers, operations project manager at the Corps lake. "And we want to keep it that way."

Myers said a dock with adult zebra mussels attached to it was transported in December from the Lake of the Ozarks and placed on Pomme de Terre Lake.

Lake of the Ozarks is already infested with zebra mussels and the dock was only out of the water a short time before being placed in Pomme de Terre, so the mussels were likely still alive and there is a good possibility that some of them fell into the lake, according to the Corps.

It's important to act quickly, before the lake warms up, Myers said. Zebra mussels begin reproducing when water temperatures reach 50 degrees, and they can expel millions of mussel larvae that can drift and spread far into the lake.

The Corps will start releasing 1,200 cubic feet of water per second as soon as the ice melts on the lake in order to expose the shoreline and kill any zebra mussels in that area. Myers said the Corps also is working with a company to treat about three-quarters of an acre of water with copper sulfate where the dock was placed.

The chemical should kill any zebra mussels still alive in the water. The small treatment area shouldn't have any larger impact on aquatic life in the lake, Myers said.

Dock owners are being alerted to the temporary lake level decline, but Myers said most of the docks should be able to handle a three-foot drop in water level.

With the unseasonably warm weather, it is anticipated that releases can begin within the next few days. It will take approximately 10 to 12 days at this flow to lower the lake level to elevation 836.0, which is three feet below the normal pool. The lake will be maintained at this level through the winter freeze.

"There's a real good chance that once the treatment phase is complete, normal rainfall will fill the lake back up by spring," Myers said.

The Pomme de Terre dam doesn't produce electricity, so there should be no financial impact to the Corps from lowering the lake. The dam was designed as a flood-control structure.

For more information about the water release, contact the Pomme de Terre Project Office at 417-745-6411. Information about the lake levels and current releases to the river can be found by clicking this link.