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Wanapum Dam in Trouble???

7K views 64 replies 30 participants last post by  FinLuver 
#1 ·
#3 ·
[quote="cmann886, post: 913852, member:
I lived in southern Idaho when the Teton Dam breached. The results were devastating for those in the path of the flood...and that was a small dam.
[/quote]

I learned to be a carpenter rebuilding Rexburg, Ririe, Sugar City, etc. Fortunately, I was living upriver from the dam when it went.

D
 
#4 ·
Nunnally and Lenice are upslope from Wanapum, so no worries there. And Wanapum is upstream of Priest Rapids, so PR can also be drawn down if necessary to partially re-regulate any sudden breach at Wanapum. If the condition requires a major draw down for very long, this does not bode well for the spring smolt out-migration. The reservoirs have to be near full pool for smolt bypass facilities to function and to provide spill for smolt passage. Under a major draw down condition, all water goes through the turbines. This could get exciting for Grant PUD if the spring runoff produces high flows.

Sg
 
#6 ·
Salmo G.....talk more about the downstream migration of smolts through that dam. Be interested in knowing what options the PUD has for the downstream migration mitigation IF the dam remains below full pool.

David.....Bad news for the city of Portland. Looks like power rates will be going up in Oregon.. Oh well, they needed to learn how to conserve energy anyway.
 
#7 ·
Salmo G.....talk more about the downstream migration of smolts through that dam. Be interested in knowing what options the PUD has for the downstream migration mitigation IF the dam remains below full pool.

David.....Bad news for the city of Portland. Looks like power rates will be going up in Oregon.. Oh well, they needed to learn how to conserve energy anyway.
Everything is getting more expensive anyway. PPNL is constantly trying for double digit rate hikes, as it is.

So I and Portland are pooched anyway. I'm going to install solar. Or build my own reactor. Or burn dung.

At least I can fish. It'll be cheaper than staying home with the lights and heat on.
 
#11 ·
Vladimir,

I don't know. Wanapum is a run of river dam and project and intended to operate with the pool elevation within a fairly narrow range. I don't know if the dam has an ROV (river outlet valve), not all do. I don't know if it can be drained below the penstock invert. I'll check with my engineer co-worker Monday. He works a on the mid-C projects and knows who to ask for answers.

Sg
 
#12 ·
Anybody fishing downstream of the dam.... BE CAREFUL! They're drawing it down fast, and are issuing flash flood warnings for all of western grant county. Not just the mainstem Columbia, but creeks, gullys, any drainage lower than the dam is susceptible(they're warning). So if you're fishing certain spring creeks, watch your six.
 
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#14 ·
A 32 foot crack is significant. I heard they are drawing it down quickly to relieve the pressure but to take it out would cost millions of tax payers' money. Probably better to survey and repair if possible before anyone starts talking about removal. Look how long it has taken on the Elwa and that stretch of the Columbia is twenty times greater than the Elwa or larger.
 
#15 ·
A 32 foot crack is significant. I heard they are drawing it down quickly to relieve the pressure but to take it out would cost millions of tax payers' money. Probably better to survey and repair if possible before anyone starts talking about removal. Look how long it has taken on the Elwa and that stretch of the Columbia is twenty times greater than the Elwa or larger.
Just means we should get started now. It'll take a while.

I'm under no illusions that this would lead to removal. Just dreaming.
 
#20 ·
Salmo g. No ROV on any Mid-C dam. Only Chief Joe and G.C. have pen stocks.
At Wanapum and Priest Rapids power production would be terminated well before the spillway flow would stop.
Wanapum has been drawn down four ft. so far today. It looks like they will hit their target of 551.5 by the time day shift goes to work on Monday.
Priest Rapids is being operated with in its normal level of one foot from the top.
That tells me not to worry. They have a problem and when it is safe to do so closer inspections and survey will determine a strategy for repair.
 
#21 ·
My office is directly below Wanapum Dam. I heard about the issue last week and headed for a meeting in BC. I got back and immediately headed for the Hoh. Tomorrow I'm headed for Omak. My idea is to keep having out-of-town meetings, vacation, and weekends until they get it figured out before heading back to the "office". The downside to not being in the office is I don't have any intel that has not made the press releases yet.
 
#24 ·
This appears to be a very serious issue for Grant PUD and for fish. The dam is 55 years old, so the PUD should have more than recovered its initial investment, but Grant's reputation for having the lowest electric rates in the nation may be at risk, depending on the costs associated with fixing this problem. A major repair could be measured in years, and I suppose, hundreds of millions of dollars. Yes, the worst case could be that serious. Hope it's not a worst case scenario.

It looks like the dam near pier 5 has shifted downstream about 6". Maybe this isn't too big a deal, and its just settling, perhaps associated with the huge concrete pour on the upstream side of the non-powerhouse section of the dam. But the basalt foundation of the dam is on a geologic fault. The fault can be seen in photos taken across the valley, and it extends down into and across the river. If the fault has moved, even 6", this could pose a serious and extremely expensive repair to the dam.

Now for the fish. The best news so far is that there is no good news. With the preliminary drawdown of 20', neither the upstream fish ladders or downstream fish passage bypass are functional. That's right, when the first spring chinook arrives at Wanapum within two months, the existing fish ladders cannot pass fish. At least not as is. Alternatives include jerry-rigging a water supply to the fishway entrance so that upstream migrants can be trapped and then hauled around the dam. The other alternative is to trap-and-haul from the one ladder at Priest Rapids that is equipped with a fish trap. Downstream passage can be effected by spilling at the Wanapum tainter gates. But with a lower reservoir level, smolts like chinook may be more attracted to the turbine penstocks than to the spillway gates.

If the pool surface elevation has to be drawn below the spill gate invert, then the only water outlet is the turbine penstocks. (Maybe penstock is the wrong term for a dam of this design, but it refers to the open water passage from the upstream side of the dam through the turbines and out the raceway.) That would kind of undo all the improvements recently made in downstream smolt passage migration. But thus far no one knows how deep a drawdown is going to be necessary. 2014 is going to be an exciting year for Columbia River salmon and steelhead.

Sg
 
#29 ·
But the basalt foundation of the dam is on a geologic fault. The fault can be seen in photos taken across the valley, and it extends down into and across the river. If the fault has moved, even 6", this could pose a serious and extremely expensive repair to the dam.
Sg
I guess the box with the question "is the proposed dam site on or perilously close to a geological fault line", was missing on that application... or removed for convenience Gas Font Heat Pattern Event
 
#27 ·
David D.,

I don't expect Grant PUD to be fined for unintentional taking of ESA fish. Of course, neither Grant's FERC license or its HCP with NMFS and USFWS anticipated a fault crack in the base and foundation of the dam. Grant's $$ penalties will come in the cost of repairs. Worst case, this will be a major construction project. Best case, it's gonna' take a lot more than a few tubes of caullking compound.

Sg
 
#31 ·
FSA,

When plans were made, prior to 1959, Wanapum seemed like the best site because of the basalt bedrock under the river at that point. Why geologists thought the bedrock on or near a fault would never move is way beyond my expertise, not to mention, pay grade.

This is getting complicated and involving pool elevations at upstream dams, which then involves fish passage facilities at those dams. The Wanapum draw down means the entrance to the Rock Island fish ladder is out of water. I keep learning more - there must be a ton of investigators looking into this - and it's not getting better from an electrical energy or fish passage perspective.

Sg
 
#36 ·
It moved back upstream an inch!? I can see it stop moving, but how does taking pressure off make it move back?
 
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