Plans have been in the works for quite some time on a project to replace two earthen dams at Newport’s Big Creek Reservoir with one new concrete dam. Because of the likelihood that these existing dams would fail in the event of a coastal seismic event, the sense of urgency regarding this project goes far beyond Newport, with support coming from the state and even federal levels.
As things continue to more forward, an outreach effort is underway to raise awareness and educate people both within the city and throughout the larger community. To that end, several tours were held last week to explain the project, from what created the problems to the process underway to build a new dam.
The Lincoln County Leader attended one of those tours and received an update from Renee Morris, director of community outreach for the Big Creek Dam Project.
“First and foremost, what is the problem, and it’s really two problems,” said Morris. “Big Creek Dam one and two, they’re earthen dams that were built in the late ’50s and ’60s, and they’re just old. They were built to standard, there’s nothing wrong with the way they were built, but the foundational soils that are underneath them, that’s the problem. They’re unsteady at this point, should we have some type of seismic event.”
But a few years ago, there was a problem discovered that could cause the upper dam to fail even without an earthquake occurring. “The new problem, from 2019, is that there’s seepage in the spillway of the upper dam,” Morris said. “If you go on our website (SaveOurSupplyNewport.com), you can actually see a photo that is taken from inside the spillway. To us it’s going to look like a crack in the pipe, but there’s water pressure that’s pushing water through.”
As more time goes on, more of the seepage issues are being determined. “There’s going to be a new study started here shortly on evaluating where we are at now with that seepage issue,” Morris said. The bottom line is that this seepage problem could grow to the point where it causes the upper dam to fail, and the rush of water from that breach would most likely take out the lower dam as well.
“Those two issues have caused the state dam engineer to give us some not great classifications of our dam,” Morris said. “So the foundation soil issue means that we are potentially unsafe. The seepage issue in the upper dam actually means we are unsafe. That means we have to do something about it immediately. We’ve had a few Band-Aids put on the actual seepage problem that’s going to get us through, but it doesn’t solve the problem, and it doesn’t stop new seepage issues from occurring.”
The lower dam contains about 200-acre feet of water in that reservoir, and the upper reservoir is 970-acre feet, “so all of that translates into 50 some million gallons of water, and that’s what would come through,” said Morris.
“Not only is it Newport’s sole water source … but also the way that it would wash down would wash out (Highway) 101,” she added. “So now we’re losing connectivity for anything that would need to happen, and of course we would probably be in a state of emergency, so it just complicate things.”
Construction of a single replacement dam will create a larger storage capacity, which would also decrease the need to pull water from the Siletz River during the summer to replenish the current reservoir. “So being able to store more water, collect more in the watershed as well as be able to take less off the Siletz in those times, will help improve the ecology all the way around and also have the larger capacity to store for future needs,” Morris said.
Another issue that needs to be addressed with this project is that of fish passage up Big Creek.
“We’re got fish passage mitigation that needs to happen,” Morris said. “The original dam was built with a big concrete fish ladder. That ladder is not in great condition and no longer works. We’re looking at other locations where we can help improve the environment for the fish.”
Verena Winter, lead engineer for the Big Creek Dam Project, told those on the tour the money that would be required to restore this Big Creek salmon run would be better spent on improvements at another location. “The cost benefit, and ODFW agrees, is that it would be more beneficial to help the salmon elsewhere,” she said. They are exploring various options on the most effective way to do this — this mitigation effort is required to be done within a certain radius of the dam project. “We’re meeting with representatives from Boone Slough out on the Bay Road,” she said. “They’ve got a tide gate that isn’t functioning properly, and it’s a good mitigation site.”
To date, $21 million has been disbursed to the city of Newport to help fund planning and design of the Big Creek Dam Project, and there’s roughly an additional $35 million worth of grants currently being pursued at the state and federal levels.
Morris said another $60 million in federal funding has also been appropriated for this project, but she pointed out that there is a difference between funds being appropriated, then approved and finally dispersed.
“So we have $60 million (in federal funding) that was appropriated,” she said. “So that means that whoever approved it said, ‘Yup, we want to give them the money.’ It could take another 60 years before we see a penny of that. If that $60 million comes through, fantastic.”
The current estimate is that the entire project will run as much as $123 million. So with the $21 million already in hand and another $35 million in grants that look promising, “we’ve got an $80 million deficit,” Morris said. “So that is what we’re working towards, filling that over the next few years as we finish the design.”
Winter said they are anticipating around 30 percent of design work to be complete by the end of this year or early next year. “If everything goes well, best case scenario, design takes about four years,” she said. “We’re one year into it, so in another three years or so we’ll be done with design. And construction, if we have the funding and everything goes well, it will take another four years.”
Morris said their outreach effort is ramping up, and more events are planned throughout the year to educate the public on this project. Also, a website was recently created solely for the purpose of informing people about this issue. That website is SaveOurSupplyNewport.com
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