The proposed dam site is on the Chehalis River near Pe Ell in Pacific County. (Photo courtesy of The Chronicle)

The proposed dam site is on the Chehalis River near Pe Ell in Pacific County. (Photo courtesy of The Chronicle)

Chehalis Basin board sets sights on saving Chinook

  • Mon Oct 7th, 2019 4:30pm
  • News

By Jordan Nailon

The Chronicle

Chinook salmon were the topic de jour at a regularly scheduled Chehalis Basin Board meeting on Thursday. That meeting, held at the downtown Centralia train station, covered a wide array of topics, but no subject was given more time and consideration than the future of fish in the Chehalis River system.

Edna Fund, of the Lewis County Board of County Commissioners, said that the dire straights of Chinook salmon, also known as king salmon, in the Chehalis River had never been more clear than after Thursday’s six-hour meeting.

“One thing was how important the Newaukum and Skookumchuck (rivers) are to the spring Chinook,” said Fund. “They could be a part of the solution, or the problem, so that was a bit ‘ah-ha’ moment for me.”

A presentation on the evolving aquatic species restoration plan for the basin included a stat from the Washington Department of Fish and Wildlife that estimated 60 to 90 percent of all spring Chinook found in the river system originate from either the Newaukum or Skookumchuck rivers. That’s a scenario that didn’t sit well with many board members, including Jay Gordon of the Washington State Dairy Federation.

“Houston, we’ve got a problem with spring Chinook,” deadpanned Gordon before putting the situation into context.

“I plant corn in a lot of different fields so that if it hails on one field it doesn’t hail on the other. Right now, we’ve got our entire crop in two basins and it’s a risky proposition,” he explained.

The board’s aquatic species restoration plan is a comprehensive effort to boost populations of endemic species throughout the basin. However, salmon appear to be the focal point of those efforts since they are the unofficial symbol of the region. Those efforts include the creation and repair of riparian zones, spawning grounds, and habitat.

On the other end of the spectrum, though, is the concerted push to build a dam at the headwaters of the Chehalis River near Pe Ell. That dam, if approved and constructed, would act as a tool to reduce the impacts of major flood events. Of course, with more and more dams being torn down around the region it has proven difficult to convince all interested parties of the merits of a structure that could both limit the migration of fish and alter the natural hydrologic systems on which those native fish depend.

“There’s a lot of people who aren’t going to like this plan and they are going to be loud about it. And they will degenerate this part of the plan (aquatic species restoration) in order to take away from the other part of the plan (dam construction). They will say that this is a lot like ringing parsley around a flood control water retention project,” insisted Steven Malloch of Western Water Futures.

Malloch, who was appointed to the board by Gov. Jay Inslee, is uniquely qualified to speak on the issues at hand since he has been a part of numerous dam removal projects around the state. For his part, Malloch was an unabashed supporter of the outline of the aquatic species restoration plan. He stated that comprehensive plans of its ilk provide the only hope of restoring historic salmon populations in the Lower 48.

“What do I think about dams? I think there’s a lot of them that need to come down. Does that mean we’ll never build another one? No,” said Malloch. “Sometimes I wish I wasn’t on this board because there aren’t any easy answers. Even the people who say no dam, I don’t believe that’s an easy answer. What about the people whose homes are getting flooded? What about closing I-5? Those are real consequences and they deserve real consideration.”

To that end, Ed Zapel, senior hydraulic engineer of HDR Inc., gave a detailed presentation on the design, function, and proposed operational protocol for the dam. Zapel spent considerable time explaining the unique form of the dam that has been designed to allow free passage for fish, both up and downstream, at all times other than during high-water events. Those considerations include five large holes at the base of the dam that would allow fish to migrate. The largest of the holes would be 12 feet by 20 feet and located at the center of the dam structure where a natural bedrock channel exists today. The other four holes, situated two on either side, would measure 10 feet by 16 feet. According to Zapel, those passages would typically be about half full of water during normal river flow conditions.

Zapel stated that the dam would only be used for water retention when major flooding is predicted. Specifically, water retention operations would begin any time the river flow at Grand Mound is predicted to reach 38,000 cubic feet per second. By comparison, the flood of 2007 reached 71,100 cfps at Grand Mound and the flood of 1996 hit 72,100 cfps.

Zapel estimated the water-storage capacity of the dam would be 65,000 acre-feet, and could result in a reduction of flood water by between 9 and 27 percent between Pe Ell and the mouth of the Newaukum. That equates to a drop of about 10,000 to 20,000 cfps.

Zapel explained that the usefulness of the dam will depend largely on where precipitation falls for each event. He added that the main center channel of the dam structure would remain open even during flood events so that flows never drop below 300 cfps from the dam and fish, in theory, are still able to migrate. By comparison, flows from the headwaters of the Chehalis typically range between 60 and 300 cfps. Zapel said the river spikes above 1,000 cfps about two or three times per year on average.

Zapel added that there are also considerations in place for a collection facility below the dam that would allow fish headed upriver to be gathered and either held until high-flow conditions improve or trucked around the dam itself. Similarly, there would be a debris-collection facility upstream of the dam that would catch large debris like trees and root balls before they can become lodged in the dam. Those debris could then be trucked downstream and released back into the river in order to provide much needed habitat for fish.

As for the estimated lifespan of the dam, that was one aspect that Zapel did not have a specific answer for.

“I don’t know. Concrete lasts a long time. I suppose as long as we want it to,” he said.

On the contrary, he estimated that the project would take five years to complete once, or if, it is approved. That timeline includes one year of prep, three years of construction during low flows in the summer and one year to commission the facility with finishing touches.

Fund was particularly fascinated by Zapel’s presentation and the corresponding dialogue amongst board members and the general public.

“Because I’m on the control zone district for the water-retention facility I was really interested to see what the dialogue would be about that structure,” said Fund. “We’ve got to overcome this image that everyone gets when you say dam where there’s all this concrete in the water and the fish have no livelihood after this. That’s why I try to avoid the word ‘dam’. The other piece that’s important to remember is that if we don’t do anything we can kiss the spring Chinook goodbye.”

One aspect of the project that was brought up on multiple fronts is the effect that climate change could have on both the severity and timing of flood events. Zapel noted that climate change could push flood events into late winter or early spring, and could also cause rainfall to drop in more concentrated bursts.

“Of course when you’re in government, things don’t go as fast as you want them to go. Everytime it rains I get like, ‘Ahhh!’, how much longer until we get another flood,” lamented Fund. “Climate change is not our friend, so what can we do?”