Lake Level following 3 day flush - CRC still open

wayne gustaveson

Moderator
Staff member
#1
The jet tubes at the dam were opened on Monday (Nov 5, 2018) and 38,100 CFS of water was released Mon, Tues, through Wednesday. The lake level (tracked on http://lakepowell.water-data.com/) indicate that the lake level dropped from 3590.27 on Nov 4, to 3589.85 (Nov 5), to 3589.09 Nov 6th.

This means that the Castle Rock Cut is still open. There was still 7.5 feet of water in the Cut when I came through yesterday at 3 PM.

Be extremely carefully when coming through the Cut, but my guess is that the Cut is passable for a few more days. I will try to get out there one more time before the weekend is over and let you know what I find.

Here is a report from Lake Powell Life:

Starting November 5, 2018, over at Glen Canyon Dam and lasting sixty hours a high flow experiment will be conducted. It’s only has happened eight times since 1996 the Glen Canyon Dam high frequency experiment (Controlled Floods). At 11 pm on November 5, the first bypass tube was opened up to about twenty-five percent shortly after the first tube was opened John Lux a control room operator at Glen Canyon Dam opened bypass tube three, at noon tubes two and four were opened. By 2 pm all four hollow jet tubes were opened at seven five percent which equals 15,000 cubic feet per second with an additional 23,100 cubic feet from the power plant that totals the volume to 38,100 cubic feet over the next sixty hours.

This controlled flood with help moves sediment down the Colorado River the way the rivers natural flow. The surge will help build beaches and the Grand Canyon and Lake Mead. The construction of Glen Canyon Dam prevented the sediment from flowing down the river like it naturally should raise the concern for the control floods. The beaches and sandbars that the control floods rebuild can impact recreation use along with wildlife and fishing said Marlon Duke from the Bureau of Reclamation Little Colorado region. Duke said, “the loss of the water from Lake Powell in this control flood is about seven inches, but once the spring comes around with the runoffs from snow the water levels will level out to normal.”

All seven generators will be running at full capacity during this control flood at the Glen Canyon Dam. The Western Area Power Administration, a branch of the U.S. Department of energy that uses the water from the dam to provide power. There is a hydro powering cost to do the controlled flood because the water that goes through the bypass tubes bypassing the generator that produces electricity from the power distributor’s eyes that’s energy loss. W.A.P.A will be affected from the controlled flood and have to spend around $920,000 to find sources to provide power later on in the year.
 

Flipper

Well-Known Member
#2
I almost understand the reasons for doing such a flush to redistribute silt and sand for beaches and habitat down stream. What I don't understand is why now? A drop like this causes unnecessary work for the marinas and their crews that maintain the boat storage areas plus all the other things that have to be adjusted when the water levels change. It also waste kinetic energy in the form of stored water above the generators that could be used for electricity generation. My biggest personal complaint of which any one making these decisions could care less is that is displaces the fish and slows the fishing for a week or so. Maybe that is selfish on my part, but I do really enjoy my fall fishing. Why don't they do this in June when there is about 40,000 cubic feet coming in? If they did that the lake would stay level for four or so days, save a lot of work for the marina crews and nobody would even no it was going on? The June time frame would also be a much more natural time frame to do it being it would happen when it would naturally due to the runoff?
 

fastarget

Active Member
#6
I wonder if the benefits of this experiment out-weigh the costs to the lake and the 920,000 to WAPA and others. It is not who came up with the idea it is who approved it.
 

Dave I.

Well-Known Member
#8
There are a lot more lake runners in June than there are river runners. This past year, I had customers that said there was too little water and had to carry their rafts for over 50% percent of the river, but that is also above the dam. But, regardless, I have never heard a river runner complain about the river level being too high.
 

Cliff

Well-Known Member
#9
The river would probably be well above the then current sand bars as the sand bars are carried down stream with the flood. Where would they stop for the nights on the river? Not all river runners are equipped to handle that high of water. I can remember as a young kid how big some of the rapids were before the dam went in. Only professionals need apply. All one needs to do is go look at what some "pass winners" use to ply the river on. I have asked several pro runners what they think of this or that rig that is setting up at Lees Ferry and they just shake their head. The risk for the government agencies would be way too high to allow the flood during the summer.
 

botnb

Well-Known Member
#10
What did the "river runners" do with a spring runoff of 60,000 fps, the was a natural event , bitch to the feds ????
 

Cliff

Well-Known Member
#12
They didn't have the thousands of amateurs going down the river then. No lottery draw either. Just like climbing Mt Everest back then compared to today. Many die each year now as thousands pay someone to help them up the mountain. I don't think many went down back then during the highest floods. Almost suicidal back then.
 

Dave I.

Well-Known Member
#13
So, back to the question. Why have these "experiments" at all? Before the "experiment" there were sandy beaches for the runners to camp on. Why feel the need that they need to be flushed farther down river? Why feel the need to kick Lake Powell while she's down in a drought year? Why do the officials think they need to mess with the assigned release of water for these experiments at all? It makes no sense to have these experiments just to move sand around. The wildlife will adapt to where the beaches are, so should humans.
 
#14
Read a big article in today paper here in Grand Junction on the river and drought. It was held at CMU with 7 states and 1 Indian representatives. Their big concern is getting more upstream reservoirs and maintain the levels in Powell first. Funny how nothing was mentioned about the big flush.
 
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Cliff

Well-Known Member
#18
I've never heard the flush is to help the chubs. I've never heard anything about why, other than they want to see how it moves sand around. Don't we know what it does by now?
Hence my question in light of no other information- When does an "experiment" end and a normal way of operating begin? What are we experimenting for after several episodes all with the same outcome?
What is the underlying reason? I don't have the answers, I'm just asking the question.
 

Cliff

Well-Known Member
#19
In doing some more research it seems that for several years now there is a growing concern over the increasing population of Brown Trout in GC (most centered on 4 mile Bar). They were stocked near Bright Angel back in the 20s and 30s and seem to have moved upstream with the fall flows. The numbers have skyrocketed in direct correlation with the years of FALL timed HFEs! There seems to be a direct correlation here. Many ideas were put forth in 2017 but with mixed reviews on effective ways to combat the increase of BT. One item missing from the proposed ways to deal with the issue was angler participation in their removal. That wasn't even mentioned in the report I read. It was mentioned briefly in another report by way of prizes or bounties for capture and kill of brown trout.

One item that came up a lot was electrofishing for removal but the Indian stake holders will have trouble with that as they have issues with killing anything without a beneficial use.

Spring times HFEs and "trout management" flows were the bigger ideas. Most felt that if not addressed the rainbow trout fishery will disappear.
 

Cliff

Well-Known Member
#20
BTW, forgot to add- the rainbow trout fishery has been in a steep decline for at least 4 years now as shown by the average hourly catch rate. 50% of the RBT are 6 inches or less. At least the way I read the charts.
 
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