Chloe and I were met at the gas station in Hornbrook by Mark Betancourt, a friendly and easy going reporter writing a story for EOS on the reservoir sediment. Unfortunately for his story, he got stuck with me for the whole day! He asked a lot of insightful questions which I did my best to answer. Change had slowed on the river and much was the same as two weeks before. Meander bends had increased, maybe the river had widened and incised a bit more but after the dramatic changes of the last several trips, this one felt rather tame. One interesting tidbit was that the tributaries had begun flowing on the surface of the reservoir sediment where they had mainly been disappearing into the soil in previous trips. Could this be a sign that the sediments are draining and becoming more cohesive? Many small gullies had been etched into the previously flat terraces above the main river in both reservoirs, as shown below.
We had seen a spike in SSC and river flows in the preceding days which was confirmed by the Timelapse cameras. Iron Gate had refilled all the way to the confluence of camp and scotch creeks between the 14th and 20th of the month, with reservoir elevation peaking sometime on the 20th. The videos below show the action in Iron Gate over this period.
IG01 showing fluctuating reservoir levels
IG02 over the same period. Note the reactivation of the bank mudflows as the high water recedes from Feb 20-26
IG03. If you're quick you can catch the bald eagles in the tree in lower left of image. I've seen more than six there on my visits.
IG04. Note how the refill event allows the river to establish an even wider channel upon base-level lowering. The flows on Feb 12 and Feb 26 are almost identical. ~750 cfs. This appears to be close to the upstream extent of the refill event.
IG05. The tributary also uses the high flows and raised base level to establish a wider channel. It's a little difficult to tell without point matching a little closer, but I believe it incises slightly through this time step as well which is intriguing because it is running through what appears to be its historic gravel/cobble bed.
At Copco there was no refill event but the high flows came down through the same period.
CP01. Higher flows come down but no ponding occurs even here just a few hundred yards upstream of the dam
CP02. The river here widens and bends more deeply into the high bank on image right
CP03. The river increases its meander bend and the high velocity flows generated by the mid-channel bar continue to incise. By the 26th, cobbles are present at the bottom of the steep bank in the center of the frame. The camera unfortunately slips throughout this period and was readjusted during the visit here.
CP04. Several large mudflow failures can be seen activating on the left bank, associated with small tributaries flowing over the surface. The main river incises and further develops the eddy on image left. Flows are slightly higher on the 26th than the 12th but the river still sits lower in its channel, evidence of continuing incision.
Below are some stills from the day.
The tributary visible in IG02. Note that it has begun to cut through the railroad grade and that surface flow is restored
The meander bend at IG03. Note very pretty stream networks developing in the mud flats
Looking downstream from near IG02. Note (hard to see) slab failures on the reservoir rim
Looking upstream at Camp/Scotch creek. The surface flow on the right I believe is associated with a spring that comes out in the former reservoir
Construction workers here appear to be cutting off the meander bend in the lower part of the frame. They had dug a channel in the center of the frame and appear to be trying to get the streams to flow through the cutoff channel instead.
Jenny creek running clear as it enters the former reservoir. By Thursday, 2/15, it was clear as it entered the mainstream Klamath, perhaps indicating that, at least for now, erosion has stopped in Jenny creek. I was unable to observe if it was clear at the confluence from the road
Mark takes in the immensity of the landscape near CP02
Looking upstream from near CP03. Note that the thalweg has shifted into the river right side of the mid-channel bar sometime in the last two weeks as the river has continued to grow the outside bend
Greatly increased tributary bank failures can be seen here, looking just upstream from CP04. The mudflow failures seen in the lower and central parts of the frame are associated with surface flow and a small tributary to the left of the image
The Klamath runs into the former Copco impoundment and doesn't stop until it reaches the Pacific.
See you next time!
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