Permits allow public to install bottom barriers

SANDPOINT — Waterfront landowners on the Pend Oreille can now take a hands-on approach in tangling with Eurasian milfoil.

The Idaho Department of Lands is granting landowners permits allowing them to install their own lakebed bottom barriers to control the submerged noxious weed around their docks and shoreline property.

The permit is available only to landowners on the Pend Oreille Lake and the Pend Oreille and Clark Fork rivers.

“The department is trying to be as proactive as it can be in controlling this weed,” said Jim Brady, a senior resource specialist at IDL’s Sandpoint office.

Landowners seeking permits must first contact Bonner County noxious weed superintendent Brad Bluemer, who has to positively identify the presence of Eurasian milfoil (as opposed to native milfoils or other aquatic plants). Once a positive identification is made, property owners can then apply for a $50 permit from IDL.

The barriers, which compress the milfoil and block sunlight to inhibit growth, can only be constructed using a gas permeable membranes or fabrics attached to frames made of PVC tubing. Landowners are limited to five barrier panels in a single location and they must flip them over or move them every six to 10 weeks.

They must also be removed by the end of the season.

The barriers can shift from a blessing to a curse if they are not properly maintained, according to Brady. If neglected, a layer of sediment will form over the barrier and allow new plants to take root, a problem the state of Washington encountered when it liberalized bottom barrier use.

“They’re still cleaning up that mess,” said Brady.

Officials are strongly recommending landowners work with local dive outfits experienced in installing and maintaining bottom barriers to maximize their effectiveness and minimize problems.

The bottom barrier program follows a recently completed project conducted by the Tri-State Water Quality Council, which secured an Idaho Department of Environmental Quality grant to install 8,000 square feet of bottom barriers at Bottle Bay.

During the project, the 10-foot by 10-foot membrane barriers were moved to different sections of the infestation every six to 10 weeks during the 2006-07 growing seasons. The success of the project allowed IDL to develop a permit process for landowners, Tri-State officials said.

“We are hopeful that allowing private individuals to use bottom barriers will reduce the amount of herbicide applications into our waterways,” Diane Williams, the council’s executive director, said in a news release.

Although the council advocates for milfoil countermeasures which don’t involve herbicides, it points out that the county’s herbicide program is regulated and involves licensed applicators, public notice and water quality testing.

“That’s not the case when private individuals apply aquatic herbicides that are readily available for purchase through magazines and catalogs,” Williams added.