Divers Down On Milfoil When All Else Fails To Control Weed, Counties Take Matters In Hand

The pile of plants looked like a bunch of long, moldy rat tails in the Mud Hole parking lot.

The plant, Eurasian milfoil, is about as desirable as diseased rodents and has taken hold in some Idaho and Eastern Washington lakes in recent years.

Divers pulled up this pile from the Pend Oreille River bottom at the Priest River confluence.

“Pouring more chemicals in the water doesn’t seem to be the answer,” Doug Freeland, of Kootenai County Weed Control, said during a demonstration Monday on how to dive for weeds.

When Bonner County tried treating milfoil in Albeni Cove with chemicals, it appeared to have no effect, he said.

So Kootenai and Bonner counties are hiring teams of divers who attack Eurasian milfoil infestations at their roots. They reach into the sediment, yank out the invasive plants, then stuff the long stalks in a vacuum tube that sucks them to a barge on the surface.

The small barge collects the weeds while allowing the water to drain out.

“We just pulled up a 25-footer out of here,” a worker called out to visitors drifting nearby. The divers had to come up and fix the pump, which got jammed by the weed.

Milfoil is spread mainly by boats. The tiny bits of weed travel on boat trailers or motors from waterway to waterway - like rats on a ship. Idaho is one of only three states that isn’t overtaken by the weed, Freeland said.

About 17 miles of Hayden Lake shoreline and another 15 miles of Spirit Lake shoreline have been weeded by divers, yielding some 20,000 pounds of slimy harvest.

Now the Pend Oreille River is getting the hands-on treatment. Local weed supervisors don’t want to attack this batch of weeds with chemicals, because the intake for Priest River City’s water supply is downstream.

Mowing the plant down isn’t a solution, because the bits and pieces of milfoil will just start new infestations elsewhere.

But standing by and watching it grow, creating labyrinths of impenetrable mats, simply isn’t an option, weed supervisors say.

“If we can keep the infestation down here, we have a pretty good chance of it not taking over the habitat we have now,” said John Coyle, resource manager for the U.S. Army Corps of Engineers at Albeni Falls Dam. “It could take over wetland habitat.”

It can also kill people. According to Freeland, five Washington state drowning deaths in the last two years have been attributed to tangles with milfoil.

Washington has had a problem with Eurasian milfoil for years, but only recently has it started to infest small Eastern Washington lakes, said Nancy Weller, lakes/watershed manager for the Washington Department of Ecology in Spokane.

Most treatment is with chemicals, but some diving is taking place on Liberty and Diamond lakes. Weller said the state is trying to make it easier to get permits for “diver dredging,” as it’s called.

Idaho now leads Washington in using divers to attack milfoil. But then, Idaho may still be able to get its milfoil problem under control.

Milfoil turned up in Spirit Lake five years ago.

Bonner County’s milfoil problem emerged two years ago in the Pend Oreille River. Hayden Lake is the only other lake in Idaho with a confirmed Eurasian milfoil problem.

Early detection, with the help of divers, is the key to keeping the weed under control, said Freeland, a diver himself who lives on Spirit Lake.

The infestation being weeded now on the Pend Oreille River is the size of nearly two football fields.

“We can’t pull this whole area this year,” said Freeland, who’s helping coordinate Bonner County’s attack.

Recently, Freeland found Eurasian milfoil under the Windbag Marina docks near Sandpoint City Beach and also in Sand Creek. Those infestations are small enough that he believes divers can eradicate them.

Meanwhile, he and Kathleen Anderson, Bonner County’s weed supervisor, are looking at a combination of tools to attack the problem in the river.

“We could remove it with divers, it’ll just take a long time,” he said.

And at approximately $600 a day, that might not be realistic for a county weed department that has to deal with all manner of weeds attempting to take over the landscape.