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.
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.
Our two timelapse cameras have now been shooting 10 images a day for the last 67 days. With more than 1,200 images in the can, we thought it was time to let everyone see how the project is developing.
(tip: click the little arrows and make it full screen)
So, what’s happened since we installed our cameras? Here’s what you can see in the first video:
The lake was drawn down more than 10 feet
The minimum flow has been diverted around the site, and the pool below the dam has been drained
A scaffolding was installed to allow better access to the site
Cables were strung high across across the river and machinery lowered into the riverbed
A huge floating crane has been moved into position upstream of the dam
Blasting of the drain tunnel is progressing well
The final countdown to breach day: October 26th, 2011 has begun. If you’re wondering, no, there won’t be a way for you to watch the blast in person (I was wondering). Access will be restricted on both sides of the river. There’s rumors of security planned for the west shoreline and the NW Lake Community access is private property, so be respectful. Fortunately, PacifiCorp will be live-streaming the breach via the Internet, so you’ll be able to watch it from home. More details on that to come.
Cheers to a soon-to-be freeflowing White Salmon River!
Time-lapse photography is a cinematography technique whereby the frequency at which film frames are captured (the frame rate) is much lower than that which will be used to play the sequence back. When replayed at normal speed, time appears to be moving faster and thus lapsing. For example, an image of a scene may be captured once every second, and then played back at 30 frames per second; the result would be an apparent increase of speed by 30 times.
Processes that would normally appear subtle to the human eye, such as the motion of the sun and stars in the sky, become very pronounced. Another example: Watching a 125 foot tall dam on the White Salmon River be removed in one minute. (ok, that last part’s not from Wikipedia)