COEUR d'ALENE - The nightmare scenario is if the lakes of North Idaho and Columbia River system were to end up contaminated with zebra and quagga mussels the way Lake Mead and the Colorado River system have been.

It would devastate North Idaho because of the lost value of its lakes, as the invasive mussels attach to everything in the water and suck out all the nutrients needed by native species. They ruin boats, docks, pipes, dams and shorelines.

With current technology, eradication is impossible.

"The impact of these mussels is beyond anybody's wildest thought process," said Idaho state Rep. Eric Anderson, of Priest Lake. "These species out-compete all other things in the ecology when they're introduced."

An infestation would damage fisheries, hydropower production, tourism, and agriculture, Anderson said. He spoke Thursday during a panel discussion on invasive species at the annual Pacific Northwest Economic Region economic leadership forum at The Coeur d'Alene Resort.

"If we're not successful at the prevention of this introduction, once they're in we're going to have to live with that," he said. "It's going to damage endangered species of salmon, bull trout, lamprey, sturgeon - all the different species we are trying to protect."

An infestation of Idaho would cost an estimated $100 million, according to figures shared by the panel. If the Columbia River Basin was to become infested, it is estimated to cost $21 million initially, plus $26 million annually.

In the United States, the mussels first infested the Great Lakes and Mississippi River system. They are introduced to water bodies by "hitchhiking" on boats that have been in infested waters, then spread rapidly.

Also on the panel, Amy Ferriter, invasive species coordinator at the Idaho Department of Agriculture, said if the mussels enter Idaho waters there aren't any real control options.

In response to Lake Mead, the Idaho Legislature in 2008 passed legislation to create inspection stations at Idaho's border areas, she said.

Thorough testing has determined the mussels currently aren't in Inland Northwest waters, she said. That's done by monitoring calcium levels in lakes and rivers, as the mussels need a lot of calcium to build shells.

Idaho has 15 mandatory boat inspection stations at its borders. The state has about 240 public boat launches, and it would be too expensive to staff inspection stations at launches.

"Our budget is only $850,000 per year," she said.

All port of entry employees of the state have been trained to inspect boats, she said.

In the past four years, she said boats visiting Idaho from every state except Delaware have been inspected. Everybody that comes to an inspection station is asked what state they are from and what the last body of water the boat was in.

"This was really staggering to us how far people will bring their boats," she said.

Local, low-risk boaters get through the inspection stations much faster, she said.

There were 57 mussel-fouled boats intercepted in 2012, she said. That's up from just three in 2009.

She finds the trend disturbing, because the boats should be cleaned before heading to the state in the first place, she said. At the stations the boats are cleaned before continuing on.

Most of the fouled boats are coming from Lake Mead.

Gail Wallin, executive director of the nonprofit Invasive Species Council of British Columbia, said, "The economic impacts are really critical to our province."

She said cooperation between western U.S. states and the Canadian provinces of B.C. and Alberta is critical.

Canada itself has a lot to lose, said. Southern Alberta is heavily irrigated for farming, and B.C. is a major hydropower producing area. Both provinces have valuable fisheries and recreation areas.

Phil Rockefeller represented the Northwest Power and Conservation Council on the panel. The council works to balance fish protection with economical and reliable hydropower production.

"I makes more sense to prevent for as long as we can, and as successfully as we can, the onset or arrival of this type of infestation," Rockefeller said. "Once imbedded, we won't be getting rid of it, and we will be obliged to pay for this."

An infestation would mean ratepayers in the Northwest would be paying more for power if dams in the river systems get choked up with the mussels.

Idaho spends more than either Washington, Oregon or Montana to prevent an infestation.

Collectively, they spend about $2 million annually, with Idaho pitching in nearly half.

"I tip my hat to Idaho because it clearly has the most aggressive, vigorous and robust program of the four states in the region," Rockefeller said. "We are fortunate in Washington state that a lot of boaters coming into our state have to go through Idaho to get there."