Condit Dam - There was a dam here

today the rumble and swish of currents calls out to visitors of the White Salmon River but for those with an ear for history the canyon walls still echo with the sounds of spinning turbines the hum of hydropower you don't do a lake tap every day these are very infrequent we're now watching the River eat itself back into the sediments one of the most spectacular things I've ever witnessed in my life then just give it a few wraps around that cleat yeah within our power we are gonna try to capture every single fish we won't but we're gonna do our best these fish are extremely fragile they get a little too much handling they might die grab this one this is a fish that's four and five years old it's not something we take lightly there's a reason these endangered salmon are getting a ride fire in the hole historically you go back over a hundred years ago the white salmon flowed right through here it was a neat little Canyon and in 1913 we built Condit dam constructed to help electrify a developing region north western lake and the dam that created it must come out condit dam was completed in 1913 twelve and a half stories tall and four hundred feet across one of the largest of its era as far as dam decommissioning dam removals this is one of the big ones glacier cold water plunging 45 miles from the river source on the shoulders of Mount Adams was captured here three miles above the white Salmons confluence with the Columbia River Condit was built to divert water from the reservoir into a mile-long wood pipeline that delivered it to a Pacific core powerhouse at full capacity two turbines produced about fourteen megawatts enough for 7,000 homes there was just one problem for fish fish can make it all the way up to the big plunge pool down at the base of the dam and oftentimes when I'm standing up on the dam looking down I can see them swimming around a ladder providing fish with passage over the dam was part of the original structure but a storm in the first year destroyed it later a second ladder also washed out in the 1990s to reduce the dams impact on fish agencies required a costly passage system in the steep narrow canyon as part of the new operating license it was not a good deal for our customers so for us it was really a business decision to move towards decommissioning over 12 months contractors must punch a hole into Condit and drain the lake then the dam can be demolished and it's concrete used to recontour the site for planting with native species as removal begins the water level is lowered just ten feet to keep the work area dry below the dam but for Lakeside residents who witnessed the drawdown change was dramatic northwestern lake became White Salmon River right before our eyes it started to make a sound and the sound was a sound of Rapids and it was sounding like a typical River to empty the link completely workers drill and blast a tunnel through the base of the dam a 90-foot thick wall of concrete built to endure the ages we will use probably about 3000 pounds of explosives this is something you can't you can't do incorrectly because you only get one shot at it first of all we have to design the number of holes that are needed to be drilled the type of explosives that go into the hole how much of each type of explosive that goes into the hole and then it's its timing each of 15 blasts leading to the breach is a cascade of explosions timed precisely to create an opening 18 feet wide 13 feet tall sized in position to evacuate water and sediment quickly it's going to be like pulling the plug on a bathtub all the water behind me will drain down just like a bathtub would in about six hours more than two million cubic yards of material has collected in the reservoir and just behind the dam a five-story wedge of silt much of this will also be on the move there's no doubt that it's going to be a muddy river when this gets released it's it's going to have a consequence to the environment and the lower three miles of the river but then it's going to be short-lived got a wild female 91 biologists have spent 60 months on a plan to protect salmon from sediment most of these fish are 2530 we moved a 45 pound fish at the end of the day I am absolutely exhausted to Li fall chinook are also known as white salmon these are descendants of the ancient wild creatures for which the river is named they're big because they had to move big cobble and big gravel we have moved fish this year that have tails that are the size of both of my hands Lewis and Clark when they came through they would have seen these fish being harvested in the mouth of the White Salmon River released above Condit they will spawn in time to produce new generations emerging from the gravels after a century of absence just as the dam disappears when the dam comes out the habitat for truly fall chinook salmon will double biologists expect their numbers in the river around a thousand in a typical year could also double coho and steelhead will increase to while efforts to safeguard fish continue a century of power production winds down I have worked at this powerhouse for 31 and a half years most of a lifetime the sound of the powerhouse is something you get used to it's loud yep it's a sad day you know I've been here 33 years and it's been a great place to work Tom Becker and Dennis Brower know how to repair and maintain everything in this building before moving on to a new assignment they have one last job to do here I do think about the power house sometimes as a as an entity and I talked to her sometimes but the time for talk comes to an end turbines slow to a stop you've done a good job for a long time and you're gonna go to sleep now three minute warning after months of precision blasting and boring into the base of Condit dam the last remaining ten-foot plug of concrete is laced with high explosives behind it two miles of reservoir up to ten stories deep but only for a few moments more the demolition crew triggers a final charge we're now watching the river eat itself back into the sediments behind the dam something that's happened much faster than we expected if I had to come up with an analogy be like watching a fire geologic time seems to condense the air holds an earthy aroma as water churns up organic material buried for nearly a century the cascading sediment is exactly what planners counted on the reservoir vanishes a river canyon re-emerges in its place even more quickly than expected our prediction was it was gonna be about six hours in fact it only took two hours for that lake to drain and it really surprised me I had someone come run up to me after the the breach saying hey the lakes gone and sure enough there was the river now the focus must turn to undoing the dam exactly 100 years after the start of construction when workers arrived in 1912 they found a steep rocky canyon they had the same sort of access struggles that we are experiencing in the deconstruction part of the project heavy machinery was very limited and basically this project was made with hands and horses as many as 1500 men lived and labored here one mess-hall alone could seat 200 building Condit dam in in this power house was at for the time a very Herculean effort a 13 foot diameter pipeline to carry water from the reservoir to the powerhouse turbines was considered a technological wonder it was a would stay flow line and it was over a mile long it was the largest that had been built by that time in the 21st century it takes just one man in an excavator to erase the flowline grab what you can and pull the rod off and then the wood just collapses our goal is to remove the wood remove the steel out of the footprint of the flume and the concrete that's generated out of where the dam is will be laid back in to this footprint and then covered over with topsoil and replant it every single bit of this river is beautiful every single square it with a dam going out it's a river that will run centrally wild from its beginnings up in the mountain down to the Columbia it's pretty unique in that sense but the dam will not give up its place easily Kruse strained to shatter resistant concrete about 10,000 truckloads in five months of hammering will dislodge the dam to reach the river a hundred and twenty-five feet below I'm always impressed at how much has happened when I stand on top of the dam and look at it when I get down here to take another perspective it's like wow we got a ways to go these waters hold not one but two dams the second structure hidden beneath the lake for nearly a century is exposed we've got a timber crypt structure that was built with 14 by 14 Timbers stacked like Lincoln Logs the issue with the copper dam is we knew we had to remove it but we really didn't know the extent of access issues that we would have trying to get down in here we didn't know that until the reservoir was gone the rock-filled mini dam created a dry work area for building Condit it too must be taken out so returning fish have clear passage you try and design and build management plans - to deal with where you want to go what you're trying to achieve and then you get out on the ground and things change contractors must manage another complex part of the project restoring a two-mile stretch of Canyon the former reservoir mature plants that once grew along its shoreline like this willow are moved to the banks of the white salmon with a gardeners attention to detail just give it a good head start a little pat on the ground and on to the next one and that's proven extremely effective the planet would love a canyon carpeted with orange markers gives way to 14,000 young trees a forest in the reservoirs old footprint dozens of acres go green as landscapers apply nearly one and a half tons of seed to hold in place new slopes with grass and shrubs this is not your mother's dump truck here it's a pretty serious heavy-duty piece of construction equipment Condit does not actually leave the valley instead its new mission is to fill in recontour space once occupied by the flowline transformed into a grassy clearing in the woods crews roll out extended shifts to make the final push the demo team provides an assist the dam is gone we have gotten in we've removed everything the river is free flowing through the former project site my great-grandfather fish district water someday his great-grandchildren and future generations will have that same opportunity the white salmon is roused already by steelhead and easy Falls there's such assets they still had they're just so strong and to stand there watch them make these chumps right here up on the wall yeah there's another one right behind it okay fish experts have also arrived to scout the new Leon harnessed waters and to document changes their salmon up and through the system we just went by several reds or salmon nests that were in the river fish are actively passing upstream you would not know that there was a dam here unless you saw the the grass and the way the moss is growing the dam site as you're coming towards it in a raft it gets hard to know where it was the reservoir is rapidly becoming a memory - beneath native shoots and buds establishing on the river corridor this has been a long process with many stakeholders lots of emotions and lots of views ultimately removing condor dam was in the best interest of our customers and i'm pleased that we are able to do so in a safe and efficient manner you

Channel: Pacific Power

Views: 632,588

Rating: 4.7357092 out of 5

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Id: HES_-dKUE9I

Length: 17min 53sec (1073 seconds)

Published: Wed Aug 21 2013

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[u/br00tahl]

Good stuff