A number of people have asked for more time-lapse products related to the Condit Dam decommissioning. Here (https://vimeo.com/85659994) is a very simple but interesting time-lapse video constructed from some 7,000 images taken over a 6 hour period (one image recorded every 2.5 seconds) on blast day (26Oct11). The 6 hour time period is compressed into 11 minutes of video. The camera was situated on the upper deck of Cabin 69 (Cyphers), 0.4 miles mile upstream of the dam on the west shoreline. View is to the south, and toward the dam.
The video begins by showing a black dog wandering down to the shore for a drink, and then beating a fast retreat at the exact time of the explosion. He may have even felt the shock wave of the explosion in his tongue, although nothing was visible to those of us along the lake. The dog wore a surprisingly guilty expression during the remainder of the day, as he had wrongly assumed responsibility for a catastrophe.
The rest of the video speaks for itself. The first several minutes of the flush were characterized by the movement of relatively clean reservoir water through the drain tunnel. This was soon followed by large masses of non-suspended slurry derived from bank collapses moving forward and being discharged along with increasingly turbid erosional reservoir water. Later, when most of the reservoir water was drained, the flushed material seemed to be dominated by river water carrying a full sediment load, plus a heavy non-suspended bed-load moving in dune-like fashion below the surface. This form of bed-load movement was visible 2-3 hours into the flush (see about 4 minutes into the video) in the form of “sand waves” travelling upstream. The slow upstream progression of sand wave dunes (actually the expression of downstream movement of sand and other particles) is visually accelerated using time-lapse.
During most of this period, I was standing on the west shore just upstream of the emerging Jaws canyon section (above the mouth of Little Buck Creek and ¼ mile above the dam). Looking back to about 15 minutes into the breach, I noticed that the entire lower reservoir surface began flowing upstream for perhaps 5-10 minutes (beginning about 40 seconds into video). This coincided with the appearance of the first turbid surface water. This upstream surface flow was occurring despite the very steady and fast drawdown of reservoir level at the dam, and not what I would expect to see if the mechanics were as simple as unplugging a bathtub. My best explanation is there may have been a layer of dense slurry moving fast along the reservoir bottom, which was displacing the lower-density and slower moving surface water, thus forcing surface water back upstream. Perhaps someone has modelled this or similar situations, and can better scientifically explain the complex movements of water, bed-load and slurry happening that day. Comments are welcomed. We would also welcome guest posts, if anyone wants to jump in with meaningful information on this or other aspects of the Condit decommissioning.
Barely a year after the breach of Condit Dam, all of the concrete has been removed and the White Salmon flows freely. By all counts the dam removal has been a success–salmon have returned and spawned above the site, rafters and kayakers are regularly paddling the river, and the whole effort happened without major incident. A huge congratulations to the contractor, JR Merit, is certainly in order. Nicely done!
The most striking thing about the Condit Dam site today is the lack of evidence that the dam was ever there. It’s almost disorienting–the dam and its related infrastructure was a fixture of the landscape for as long as anyone can remember. When I walk around the site today I almost find myself getting lost. It’s weird and really fantastic.
While paddling through the site of the former dam is certainly an incredible experience, it’s really the salmon recovery that makes the dam removal truly exciting. When I pressed most biologists to predict when salmon might return to spawn, I usually got a conservative 3-4 year estimate. But salmon had already started spawning above and below the former dam site before crews had even finished removing the last of the concrete. The lower river sufficiently recovered from the sediment bomb of breach day for salmon to spawn downstream and upstream habitat remained in great shape. The biggest thing we’ve learned from this process? If we get out of the way and let nature do it’s thing, recovery will happen incredibly quickly. But, hey, don’t take my word for it. Ask this guy…
So what happens next? Crews still need to finish wrestling with the log jam in the Narrows and tree planting will happen in the former reservoir area. There’s lots on monitoring left to do and lose ends to tie up, but this dam removal’s just about wrapped!
Now, I know what you’re wondering. Yes, we have the complete timelapse footage of the dam removal processed and ready to go. And no, you can’t see it. Yet. (Sorry!) I’m producing a special for PBS about Condit and the timelapse footage will premiere with the show sometime this spring. Once it has aired, we’ll put both the complete show and the timelapase footage here on the site. In the meantime, just keep rewatching the footage from breach day…
As most folks know, this August marks the last month of Condit Dam’s existence. That really hit home this morning, as I rounded the final rock outcrop on the precipitous trail leading to the west-side Station 1. The demolition contractors were within about 10 vertical feet of intercepting the drain tunnel, and were well below the elevation of the old Cameron Bridge. In a later conversation with Garth Wilson of Kleinfelder, he explained that only 3,000 of the original 30,000 cubic yards of concrete remains to be removed. While a positive figure (i.e., 90% of the material has been removed), work space is becoming more limited as the dam recedes, and there are challenges relating to how the remaining material can be removed from the deepest part of the canyon. To do the job, it sounds like the company will be using carefully controlled explosives to fracture the lowest portion of the dam into large chunks that can be lifted out with a clam-shell bucket mounted to a large crane stationed on the original Cameron Bridge terrace.
Also today, I attempted with some success to use a Canon T2i camera for shooting some video of the ongoing work. It’s not pretty (I am not a video man by any stretch), but if nothing else, it will give folks some understanding of the current work. Of some interest is the third clip from the start, which shows the toppling and breaking of the final section of spillway apron wall. If interested, check out the Vimeo link below…
My interest in photographically documenting the removal of Condit Dam began about 8 years ago, during a year-long project sponsored by US Fish & Wildlife Service and PacifiCorp. The goal for the year was simply the expansion of public knowledge surrounding the decommissioning. During that time, Gail Miller and Arianne Poindexter of PacifiCorp provided me with an amazing collection of photos from the company’s archives, which documented most phases of the original construction. Here were images of the Greek immigrants who built the dam, their housing in great tent camps, the original equipment, and many other aspects of construction. The photos were likely a tool used by Northwestern Electric Company to monitor implementation of the project by their contractor Stone & Webster of Boston, Massachusetts. It’s also likely that they were photographing the work for posterity sake, knowing that their work was shaping the future of the Northwest.
In my work, it soon became obvious that the builders were documenting dam construction using an early “time-lapse” photo technique. For all its modern complexities, time-lapse is simply the process of taking a sequence of pictures over time from the same vantage point.
Using topographic maps, I was able to roughly determine where their main photo point must have been. It seemed that their main station had been on the very steep basalt slope above and west of the dam. Armed with the original photos, I set-off hiking one morning, starting at the original rock quarry and rock crusher site, and proceeded down the route of the old rock chute to the dam. After scrambling down and across 100%+ gradient slopes, I found a bare, east facing rock knob, that seemed to provide the original vantage used by Northwestern Electric almost a century before.
The work being done today by Andy and me is centered on documenting the removal of Condit Dam, charting the rapid changes in the reservoir sediments, and capturing a record of vegetation recovery in the recently uncovered “Condit Canyon”. This is largely being accomplished via photography from the historic west dam photo point (current “Station 1”).
The video below represents a first attempt at compiling a time-lapse sequence of pictures taken at Station 1 over the past 99 years. The first historical image gives a good overview of the canyon’s appearance in August 1912, and even a glimpse of the exact location of the upstream coffer dam. The series continues through the date the reservoir filled and water first spilled over the top on March 21, 1913. It concludes with recent images taken in late October 2011, when the dam was breached.
Removal of Condit Dam is scheduled for completion in fall 2012… some 100 years plus a few months after the very first work began…
Well folks, October 26th, 2011 is certainly a day that will go down in history. After the Blaster in Charge yelled “fire in the hole!” and ignited the charges, the White Salmon was explosively set free for the first time in 100 years. The lake took less than 2 hours to drain, carrying an incredible amount of sediment and debris downstream to the Columbia. Now, a more gradual process begins–the erosion of millions of cubic yards of trapped silt, the return of threatened salmon and ultimately the complete removal of Condit Dam.
Enjoy these photos and video from breach day and stay tuned for more updates as the sediment erodes and the White Salmon re-carves its course. And check out this National Geographic News story, where the breach video first appeared.
What a powerful few days it’s been. I’m exhausted, elated and very excited to see what’s in store for the White Salmon in the coming months. While I finally catch up on some sleep, enjoy this video clip that I put together for National Geographic that includes video and timelapse imagery.
Yesterday was incredibly powerful and almost unbelievable. Within seconds of the blast, the White Salmon burst through Condit Dam and Northwestern Lake, the reservoir behind the dam, was drained within an hour — much faster than anyone had anticipated.
I spent much of last night and this morning wading through the incredible amount of images that I was able to capture with our cameras and my computers are still cranking through the rest. I’ll be posting more images and video later this afternoon, but until then here are a few photos to whet your appetite.
And you can see the livestream video from yesterday here…