Mother Nature isn't done with the Columbia River yet

Don't blame Canada for all the water coursing through the Columbia River system.

More rain is expected in the Idaho panhandle and in western Montana on Wednesday and Thursday, adding to the Canadian snow melt and ensuring Tri-City waterways stay brimming for at least another week.

Mid-Columbia boaters and others getting near the water are warned to be careful along the river even as waters temporarily recede for a few days.

Tuesday, the National Weather Service in Spokane issued a flood warning associated with melting snow for northern Washington and portions of Idaho. In Montana, flooding on the Clark Fork River has left portions of Missoula underwater and the fresh rain means it's about to get worse.

What happens in Missoula won't stay in Missoula. The Clark Fork drains to the Pacific Ocean by way of Lake Pend Oreille, the Pend Oreille River and the Columbia River.

More than 500 miles downriver, the Mid-Columbia expects water levels to begin rising again this weekend as the Missoula flood water moves through the system.

The Northwest River Forecast Center in Portland projects the Columbia will crest at 31 feet below Priest Rapids Dam on Tuesday, about 1 foot below the "minor" flooding stage.

Joe Intermill, hydrologist in charge, said 2018 is shaping up as a big water year. High water is expected through June.

Locally, high water already has swamped docks in Richland and yielded dramatic views. But damage is reportedly minimal.

And Benton County said its $95,000 project to replace the docks at the Two Rivers Park boat launch this week is proceeding as planned.

The Port of Kennewick reports water is roaring past its offices on Clover Island, but hasn't affected the marina and boat launch, which are sheltered by a causeway.

However, Tana Bader Inglima, deputy CEO, said there is a lot of debris on the river.

"Boaters should be careful," she advised.

An advocate for more local control over the Columbia River shoreline is seizing the flooding for political gain.

The minimal damage proves the levees protecting the Tri-Cities from Columbia are too high, said Gary Petersen, a former TRIDEC official who is working with former Kennewick Mayor Brad Fisher and former Rep. Doc Hastings to lobby Congress to re-convey 34 miles of shoreline to Tri-City control.

Petersen said the group is frequently asked if the Tri-Cities could be flooded, as it was in 1948. Petersen said the current flooding shows that the flood control dams built upriver since then are doing their job.

This week's high water mark was well below the bottom of the levees, he said.

The Army Corps of Engineers controls water levels at federally-owned dams on the Columbia River depending on their primary functions. The four from McNary to the Pacific were designed for navigation and hydropower. Operators have about five feet of leeway to manage river levels.

The dams above the Tri-Cities, from Priest Rapids to Canada, are primarily flood control and power facilities, so operators have more discretion to control how much water is flowing.

At least one group is happy about all the water: Salmon.

Fisheries experts say the flooding cools the river and the fast-moving water helps salmon move quickly out of the reach of predators.

Washington state Gov. Jay Inslee has declared a state of emergency in 20 Eastern Washington counties, including Benton and Franklin.

This story was originally published May 15, 2018 at 5:54 PM with the headline "Mother Nature isn't done with the Columbia River yet."