“Last Drink” — New Time-lapse Video

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.





On Saturday, January 25, 2014, a group I was touring with along the west shoreline of the White Salmon River noted that a recent landslide had occurred on the vertical canyon wall approximately ¼ mile above the Mill Creek confluence.  The site was visited again today to get photos and the estimated size of the slope failure.


This photo, taken from an upstream vantage, shows the rust-stained surface of the newly exposed basalt, and tell-tale absence of the horizontal lines that betray the old Northwestern Lake water level (click on image to enlarge).  In the river is the conical pile of rock rubble that now slightly restricts river flow.  The estimated height of the pile is 15+ feet, and the diameter is 50 feet.  Assuming these dimensions are fairly close, the size of the landslide was about 300 tons.

Such an event obviously leads to speculations of cause.  Three ideas all relate to the current absence of Northwestern Lake.  First, the cliff rock was buoyed by reservoir water prior to 2010.  Since the weight of rock is much less underwater, the downward and outward forces that can lead to slope failures are much higher now that the reservoir is drained.  Second, it’s possible that water in the hillside is still adjusting to the reservoir’s absence, and hydro-static forces once balanced by the pooled water may still be pushing the rock outward.  Third, the rock face is now subject to freezing and thawing that can pry and destabilize the rock (see Dan McShane’s comment on this post).

Regardless of cause, landslides and other types of earth movement are very common geologic events, which can be harmful if people and structures are proximate.  Increasingly though, watershed and fisheries studies have shown that landslides are important sources of mineral and organic matter entering rivers and streams.  Input of these materials is important to providing adequately sized spawning gravel for fish, and nutrients for aquatic plants and animals.  The addition of these materials through landslides and other mechanisms is also critical to the proper functioning of floodplains, which are vital to regulating peak flows during floods.  In this way, landslides and other types of geologic mass movements may protect human lives and property.

Pre-Dam Removal Aerial Photo Showing January 2014 Landslide Location

2014 Landslide JPEG snip version

Great “Pre-Slide” Oct13 Photo of Rock Wall by Darryl Lloyd — Thanks Darryl


Condit Dam Removal Update #6

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…


Condit Dam Removal Update #5

The timelapse camera at Station 1 below the dam has been woozy since late June, which has required repeated trips to reprogram, change batteries, and just today replace the power converter circuit.  Thanks to Mark at Harbortronics in Ft. Collins, we have new parts installed that will hopefully solve the problem and get things running.

In the meantime, work on both dam removal and restoration of the old reservoir is happening fast.  I figure I’ll use the rest of this cloudy morning in Husum to provide some mid-July progress updates.  Here they are… and remember you can click on images to enlarge…

Two weeks ago I was given the opportunity to cross the dam and go through the  demolition area with Stephen Caruana of Kleinfelder and Associates (prime engineers on the project).  This photo was taken from the west hillside, and shows the ramp that leads to the original wooden flow-line route, where concrete from the demolition is being placed in the trench for later recontouring, retopsoiling and revegetation.  

This second photo was taken today (7-14-12) from Station 1, and shows how much of the dam has been busted, loaded and hauled to the spoils location along the old flow-line route.  I’d hazard a guess that 30% of the dams original height has been reduced so far.  I also noticed that Merit seems to be doing a good job of preventing the broken concrete from entering the river above and below the site.  This picture shows them using three hydraulic excavators (with jackhammer heads) to precisely break the cement into chunks that can be handled by the loaders and off-road dump trucks.  If drilling and blasting methods had been used, the difficulties with containing the broken concrete would have been much higher, and there would have been more likelihood of impacting downstream water quality and aquatic life.  

This third photo shows the White Salmon River immediately downstream of the currently breached dam.  As such, this reach was the first to feel the impact of last October’s (2010) breach.  Surprising is the fact that it has not changed much from the pre-October condition.  Note that turbidity in this section, and in the now exposed reservoir reach, is visually almost back to normal, except during days when the contractor is actively pushing reservoir sedments into the river during regrading operations (see below).  The same thing can’t yet be said for the lower river, where the gradient shallows prior to entering the Bonneville pool.  The lower river’s sediment transporting ability is still adjusting to the high sediment load, although the two are coming close to a balance.

In my way of thinking (as a person who used to earn his buck doing mined land reclamation in the Black Hills of South Dakota), this view of the old reservoir about 1/2 mile above the dam shows the most exciting aspect of the rapid-flush river restoration method employed at Condit.  The Condit rapid-flush method is interesting given that it relies on the power of water stored behind the dam to complete the first and most important phase of restoration, that being the removal and regrading of many of the near shore and low-wall sediments. The success, at least in this reach, is evident at the bottom of the photo, where sloughing of reservoir sediments to the original ground surface has occurred.  Note the 100 year old and well preserved stumps!   Above this level, where hillside gradients are shallower and sediments were more stable, thick terraces of reservoir sediment still remain.  Providing for the long-term stability of these upland terraces (to minimize erosion, sedimentation, and water quality degradation), therefore, came to be recognized as the most important component of restoration surrounding Condit Canyon.  Restoration at Condit (and all other landscape restoration projects) primarily involves “kick-starting” processes that lead to improvements in a) hydrology, b) topography, c) soil mantles, and d) vegetation.  By far, the most important targets for this work are riparian (stream side) areas and hillsides, as opposed to river channels themselves.

The active restoration seen in the background and foreground is bulldozing to regrade the perched sediment veneers back to more stable slope angles.  A small side channel has also been regraded to restore the hydrology, and enable establishment of a permanent plant cover.  Seeding and planting will occur in fall 2012 and spring 2013.  The photo also shows where the company has placed logs salvaged from the reservoir.  Logs were recently placed both horizontally and vertically on the slope, to provide sites for plant germination, shading, colonization by invertebrates, and habitat for cavity nesting birds.  

As a final note… just as PacifiCorp is successfully using very old cable logging technology and local knowledge to accomplish important aspects of the dam removal, it will be vital to use established, time-tested revegetation methods and plant materials for regenerating the forests that once occupied the slopes around the canyon.   Local foresters, natural resource specialists and nurserymen have, for the past 50 years, developed proven methods of reestablishing forests… something that is vital to addressing weed colonization, soil erosion, river sedimentation, loss of stream shade, and insufficient large wood recruitment for fish habitat.  To ensure restoration success, it will be important for the company to put high emphasis on establishing the climax forest vegetation types as quickly as possible, which is something the old-timers found a good method of doing.  

Condit Dam History – Part 2

Before hydropower, irrigation diversions and commercial rafting, the main commercial use of the White Salmon (and surrounding rivers of the Columbia River Gorge) was for transporting logs harvested along the river corridor.  Several “splash dams” were constructed, as far north as the Trout Lake valley.  When collapsed, these dams would create surges of water large enough to carry logs downriver to mill off-load sites.  Logging and farming were mainstays of the pioneer White Salmon valley economy, as they are to a large degree today.

The scene shifted in 1910 with publication of a US Geological Survey professional paper, which reported on the department’s field assessment of the hydroelectric generating potential of the White Salmon, Little White Salmon, Klickitat and Lewis river basins.  That study by John C. Stevens (Water Supply Paper 253) concluded that the basins with the highest production potentials were the Klickitat, followed by the White Salmon and Lewis.    Concurrently, Herbert and Mortimer Fleishhacker of San Francisco were seeking ways to power their Crown Willamette Paper Mill in Camas, WA.  Harnessing the White Salmon via another of their financial interests, the Northwestern Electric Company, became a possible mode.

Condit Dam History – Part 1

When looking back over the human history that surrounds the White Salmon River and Condit Dam, it is easy to forget that the lower river had been used for thousands of years by Klickitat people (and their predecessors) for harvesting salmon, steelhead and perhaps Pacific lamprey.  Some historians have estimated the native American population at Nakipanic (the village site at Husum Falls, now Husum) was several hundred.  Given that, there were more people living in the Husum town center before 1855 (date of the Yakima Treaty) than there are today.  This concentration of people lends strong support to the presence of a large and vibrant community before homesteading… perhaps more vibrant than today’s.  While construction of Condit Dam in 1913 spelled the certain end of the fishery above river mile 3.2 (i.e., Condit Dam), it’s likely that the 1855 treaty that resulted in translocation of people north to the Yakama reservation, spelled the real end of the fishery and an early way of life on the White Salmon.  The photo at left (taken from Williams “Guardians of the Columbia”, 1912), shows Jacob Hunt, who was born and lived his life in Nakipanic.