Idaho touts herbicides as best way to control lake milfoil
BOISE - Herbicides are the most cost-effective way to control invasive Eurasian water milfoil in Idaho waters including North Idaho lakes, state Department of Agriculture officials told lawmakers this morning.
“To us, today, it’s still our best tool available, to utilize herbicide first,” Lloyd Knight, administrator of the Division of Plant Industries of the Idaho State Department of Agriculture told the Joint Finance-Appropriations Committee.
Under questioning from North Idaho lawmakers, Knight said, “In some of our smaller populations, we have utilized divers to hand-pull.” That includes some of the smaller milfoil infestations in Priest Lake, around marinas in Lake Pend d’Oreille, and some areas around Cocolalla, he said. “What that allows us to do is survey and pull at the same time with divers. It can be fairly expensive, but it can be a useful tool with some of the smaller populations.”
Knight said the department hasn’t seen research showing “a high level of success” with biological tools to fight milfoil. Plus, some of those approaches involve “moving populations of milfoil back and forth, in and out of the river system. … The way our noxious weed law works, that’s a no-no. … We’d rather you weren’t transporting noxious weeds at all.”
Knight said some areas are proving resistant to any sort of treatment, including under railroad and Highway 95 bridges outside Sandpoint. Due to high water flows there, herbicides don’t work, he said, and it’s not a safe location for divers. Plus, the milfoil is located so far underwater that biological tools don’t work well. “We’re realizing we’re going to have some areas … where treatment is not going to be effective,” he said.
Rep. Eric Anderson, R-Priest Lake, a leading advocate for addressing the state’s milfoil problem, said the state’s efforts have been highly successful. “The biggest success is that we’ve held it to 14 or 15 counties,” he said. “It’s never expanded. It was certainly moving south - it was going to be in the Snake River. But we’ve checked it.”
Anderson said the amount of the invasive weed in Idaho’s waterways is “way down” from a few years ago. “I think that Ag has done a really tremendous job,” he said.
The agency is requesting $900,000 for milfoil eradication in next year’s budget, the same amount it’s been spending each year, but it’s always been allocated on a one-time basis, requiring another appropriation from lawmakers each year. Sen. Steve Vick R-Dalton Gardens, said, “It’s my understanding that there really is no end in sight for that program. Do you think that’s true, and do you think it should be part of your base budget if it’s going to be ongoing?”
State Ag Director Celia Gould responded, “Certainly I believe it’s going to be an ongoing effort. There are some opportunities for us to eradicate in certain water bodies. Certainly in other water bodies where there’s a swifter flow of water, the population is more dense … we’re going to have to control through chemical means, hand-pull, whatever suits that particular water body.”
Gould’s department requested this year that the funding next year be ongoing; it covers a comprehensive survey effort, installation and maintenance of boat check stations to identify and decontaminate watercraft contaminated with milfoil, and treatment and eradication for water bodies. However, Gov. Butch Otter recommended another one-time allocation next year.
Gould said, “We always defer to the executive branch and the legislative branch to determine how best to appropriate the money to us. We’ll get the job done however you get the money to us.”