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Well, this is some good news.

https://www.usnews.com/news/best-st...oks-boosting-spill-at-columbia-and-snake-dams

PORTLAND, Ore. (AP) - A U.S. appeals court on Monday affirmed an order to spill more water over Columbia and Snake river dams to help protect salmon and steelhead and aid their migration to the sea.

The decision came after U.S. District Court Judge Michael Simon of Oregon ruled last spring that the U.S. Army Corps of Engineers must spill more water through spillways rather than turbines that pose a danger to the fish.

He sided with conservationists who say allowing extra water to flow between April and mid-June will help young salmon.

The Army Corps, National Marine Fisheries Service and another federal agency appealed Simon's ruling.

A three-judge panel of the 9th U.S. Circuit Court of Appeals said Monday that Simon rightly concluded that the salmon and steelhead are imperiled and will remain so without further conservation efforts.

The judges also pointed to decades of studies that show higher spill volumes lead to increased survival rates.

"At best, federal defendants establish uncertainty about the benefits of increased spill, but the existence of scientific uncertainty does not render the district court's findings clearly erroneous," Chief Judge Sidney Thomas wrote in the opinion.

The new spill operations are set to begin Tuesday at some dams on the Snake River and next week on some dams in the Columbia, one of the largest rivers in North America. The Snake is its largest tributary.

Conservation groups said it's the fourth time since 2005 that increased spill has been mandated by the district court.

"It's tragic that the federal agencies are still ignoring their own science in fighting spill at every step of the way," said Glen Spain, Northwest regional director of the Pacific Coast Federation of Fishermen's Associations.

Corps spokesman Matt Rabe declined comment on the litigation. He said the corps will follow the ruling and increase spill Tuesday.
 

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I find it somewhat unfortunate that the spill advocates have worked so hard in getting folks to believe that spill and spill alone actually increases the downstream migration speed of smolts. Is this actually true? Think about it. We are talking run of the river dams here with little storage capacity. What comes in must go out. Do people really think spilling increases the water velocity?

There are only a set number of ways water can get through a dam. 1) through the turbines (generally considered the least desirable but survival studies have shown survival through turbines to be in the low to mid 90s in some cases). 2) through the spill gates (which often results in survivals in the mid to high 90s range and accepted by some as the most desirable, but gas levels increase as a result, which can harm fish). 3) Specially constructed bypass systems (not all dams have these, but survival is often in the high 90s and they don’t gas up the river like spill gates) and 4) fish ladders (this is a constant in that the amount of water passing through stays relatively consistent). While the survival percentages listed above vary from year to year and project to project, the survival rates are pretty well understood at the various projects.

Water obviously flows downstream but by just opening spill gates does the water flow downstream any faster? Spill isn’t like flushing a toilet or pulling the plug on a drain. Rather it is more like opening a faucet valve. In years with more runoff, it is like opening the faucet wider. The specific route by which water passes the dam doesn’t affect water velocity rather water velocity is more associated with the volume of water within the system. Yes, there are studies that show smolts survive better (often described as water transit time or WTT) in high flow years. But is it a result of increased spill or more water needing to flow downhill quicker? Is it a coincidence that in years of high runoff, smolts travel quicker downstream and survive better?

Dams that have no additional bypass systems and have higher turbine mortality should spill more, as advocated by the federal mandate. But dams that have the capability to pass fish at high survival rates without gassing up the river should not necessarily be forced to spill more just because some groups have advocated spill saves fish because frankly it is not that simple. Just because a group says so doesn’t automatically make it so.
 

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I'm a general spill advocate for the Columbia and Snake River dams, but BDD has a valid point. Spill doesn't affect river velocity. River velocity is dependent on flow and stream channel morpholog, or cross section. With major storage dams high in the system (Grand Coulee, Flathead, Hungry Horse, Palisades, NF Clearwater, and probably a few others I'm not thinking of at the moment, capturing spring runoff, the amount of flow in the Snake and Columbia in the spring is greatly reduced from without project conditions. The reduced flow increases out migration time. The reservoirs do, however, slow the average velocity of whatever flow there is by greatly increasing the river channel cross section by whatever the shape of the reservoir is. This further slows the downstream migration time. What spill does do is attract downstream migrants away from deep turbine intakes to the near surface or surface spill flow. Whether to spill or not at a given project depends on the differential survival between turbine and spill passage and the presence of specific smolt passage facilities that have even higher passage survival rates. To say the whole shebang is complicated is an understatement.

Sg
 

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Discussion Starter · #9 ·
As I understand it flow and spill are 2 totally different things. Flow is the amount of water they release dam to dam. Spill is how much they run through the turbines vs over the spillway.

While I see a challenge in setting flows vs retaining water for irrigation or late summer flows(water temp and oxygen levels) spill seems to be all about money. Money made by turbines vs “wasted” water flows that just spill over the dam.

What is the gas levels you speak of? Is this just another way to save flows for late summer to deal with oxygen levels or something different?
 

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Thanks Sg for helping clarify a complex situation. I appreciate your free thinking, open mindedness and avoiding the lemming syndrome. I am certainly not opposed to spilling at dams to help pass migrating smolts. But I do appreciate helping the general public understand the complexities of the situation so we just don't say spill is good or bad, without thinking about what that actually means and repeating something without understanding it, just because a group says so. There are some that may give the impression that spill will solve all our salmon problems; rather spill is one of many tools that can help the situation but is not a silver bullet in salmon recovery (whatever that means).

Often spill occurs during spring run off because there is more water that needs to be passed than capacity to generate thru the turbines, called inadvertent spill. Then there is fish spill which is generally an amount of water that needs to be spilled to aid in fish passage and this is what the courts have ruled in the news release. Or mandated in a Biological Opinion.

Yard, I don't think there is much of a connection with spill and irrigation. The photo shows open and closed spill gates. When water passes over the spill gates, air (specifically nitrogen) is entrained in the water and increases the amount of gas (called total dissolved gas, TDG) that occurs in the water. This can occur naturally at any waterfall however, man-made spill gates can create much higher levels of TDG then what is generally found in nature and often takes much longer to dissipate out before reaching the next dam downstream, which if spilling a bunch, can compound the problem. High TDG levels can be bad in that it can create gas bubble trauma in fish, a condition that is similar to the "bends" in divers.

I can kind of make out what you are suggesting about money and wasted water. Water that is spilled is essentially lost revenue in that if not spilled, could have been ran through the turbines and generated electricity, which could be sold on the market. However as mentioned, during spring run off, there is often not enough turbine capacity and water must be spilled anyway. These court-mandated rules simply specify how much water needs to be spilled to aid fish.

So while Klickrolf may be correct in his statement that the faster the smolts move out, the higher survival will be, as Sg pointed out, spill doesn't affect water velocity. But the dams have slowed the overall velocity at which water reaches the estuary and if there isn't a blob waiting for the fish, perhaps they find conditions suitable for good growth and survival and return to be temporarily slowed down upon return by me catching and releasing one so it can continue upstream to spawn and continue the cycle.
 

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YS,

Spill happens for two reasons. One is when the spring runoff exceeds reservoir storage capacity and dam turbine capacity, so the excess water is spilled. If spill is discretionary, and occurs when turbines are not at full capacity, we always said that a power engineers job performance evaluation would get demerits for wasting water, wasting generation, which translates into lost revenue. That's not exactly true, but there is an element of truth to the inside joke.

The high volumes of spill that can occur at mainstem dams, like a huge waterfall, cause air, composed mainly of oxygen and nitrogen, to be entrained and compressed into the spilled water. This creates what is called super-saturation. The oxygen is OK, but excess nitrogen super-saturation above about 115 or 120% creates a toxic reaction in fish, similar to what we call the "bends" in scuba divers, as BDD mentioned. While spill can improve downstream smolt passage survival, too much spill can create a nitrogen condition that kills more smolts than if they passed through turbines at certain dams. So it's a balancing act to provide the amount of spill that derives the best attraction with survival and the lowest super-saturation mortality. It ain't easy.

Turbines are weird. There are three main types in common use in hydropower, Francis, Kaplin, and Pelton. Kaplin turbines have the highest fish survival, and Francis are intermediate, but definitely not good. And Pelton, for all its efficiency, has 100% fish mortality. Most mainstem Columbia and Snake dam turbines are Kaplin, with some Francis, and no Peltons. Turbine choice is case specific. But better Kaplin turbine designs that are more fish friendly have been in the works for a number of years now, so there is that little bit of light in the tunnel.

I remain on the side of spill. To the extent that spill increases overall downstream passage effectiveness and survival, it's a legitimate part of the cost of doing hydro business because the human benefits of hydroelectricity are incredibly significant.
 

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Discussion Starter · #15 ·
YS,

Spill happens for two reasons. One is when the spring runoff exceeds reservoir storage capacity and dam turbine capacity, so the excess water is spilled. If spill is discretionary, and occurs when turbines are not at full capacity, we always said that a power engineers job performance evaluation would get demerits for wasting water, wasting generation, which translates into lost revenue. That's not exactly true, but there is an element of truth to the inside joke.

The high volumes of spill that can occur at mainstem dams, like a huge waterfall, cause air, composed mainly of oxygen and nitrogen, to be entrained and compressed into the spilled water. This creates what is called super-saturation. The oxygen is OK, but excess nitrogen super-saturation above about 115 or 120% creates a toxic reaction in fish, similar to what we call the "bends" in scuba divers, as BDD mentioned. While spill can improve downstream smolt passage survival, too much spill can create a nitrogen condition that kills more smolts than if they passed through turbines at certain dams. So it's a balancing act to provide the amount of spill that derives the best attraction with survival and the lowest super-saturation mortality. It ain't easy.

Turbines are weird. There are three main types in common use in hydropower, Francis, Kaplin, and Pelton. Kaplin turbines have the highest fish survival, and Francis are intermediate, but definitely not good. And Pelton, for all its efficiency, has 100% fish mortality. Most mainstem Columbia and Snake dam turbines are Kaplin, with some Francis, and no Peltons. Turbine choice is case specific. But better Kaplin turbine designs that are more fish friendly have been in the works for a number of years now, so there is that little bit of light in the tunnel.

I remain on the side of spill. To the extent that spill increases overall downstream passage effectiveness and survival, it's a legitimate part of the cost of doing hydro business because the human benefits of hydroelectricity are incredibly significant.
Thanks for talking this through. I've certainly seen the effects with NAs firing bottle rockets at seagulls below the Dalles dam.

My impression is that this is to manage spills during times of low flows at out migration time. If we had high flows throughout the system this wouldn't be an issue, right?
 

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Yard, sounds like there may be a disconnect. I may or may not be able to align us, but I do wish to add one last potentially-clarifying post and then I'll hopefully be done on the subject. This is in response to what you wrote before editing it...at least what I could remember from yesterday.

First, I am not being critical of your posts, of spill, or of the federal mandate to spill water in aiding fish migration. Next, I did not specifically refer to you or anybody else posting on this thread with my lemming comment. Rather that was directed at individuals or groups who push their agendas regardless of what the data suggest, just because that is their agenda. The comment was for my admiration of Sg and his perspective; even though he admittedly advocates for spill, he can still acknowledge that the situation is indeed very complicated. I'd like to think my thoughts fall into that same category. Nowhere in any of my posts was I criticizing the spill concept...rather I defended spill in certain situations such as dams without bypass systems, dams with high turbine mortality rates, and in high water years, which in conjunction with spill can reduce smolt migration times. I did make a statement that spill in and of itself does not necessarily affect river velocity, which was collaborated by Sg. That is a far cry from suggesting that I am against spill or I am contradicting the beliefs of fish agencies. Finally, since I was the one who brought up gas levels, to which you asked a follow-up question, I respectfully responded after which my response was again collaborated by Sg.

There you have it...that is my deal.
 

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My impression is that this is to manage spills during times of low flows at out migration time. If we had high flows throughout the system this wouldn't be an issue, right?
Yard, since most of the spring runoff is stored in the high basin reservoirs, spring flows are invariably lower than natural, without projects, flows. However, even the remaining spring flow can exceed generation capacity at the dams, resulting in unintentional spill. This is what we relied on for juvenile fish passage prior to the court mandated spills by Judge Redden a few years back. Since mandated spills have been required by the court, that passage option is also available when the dam controlled spring runoff is less than the turbine capacity at the dams. Hydro engineers, by their training, and orders from the bean counters, act like their DNA is spill averse. Just look at BPA. BPA is a federal hydropower marketing agency. However since a federal act in 1980 that I can't think of the name just now, BPA has also had Columbia River fish conservation as part of its legislative mandate. Yet BPA makes decisions 100% of the time in favor of hydro generation and would always rather spend hundreds of millions of dollars on further studies of fish passage, habitat studies and improvement and restoration projects, and some genuine fish passage facilities that actually work pretty well, rather than spill 3 cents worth of water at a dam, which is roughly what they sell one killowatt of electricity for.

I think what you're reading here is that BDD and I agree that the system is more complicated than many people think. Spill is necessary, but it is more necessary at some dams than at others. And the amount of spill relative to turbine generation also varies from project to project. With a really good juvenile fish passage system, like some removable spillway weirs, very little spill is needed. At other projects, no known juvenile fishway is feasible, or it may be the case that just spilling water in the spring is cheaper than what a truly effective fish passage facility might cost. The job of the policymakers is to let the engineers and biologists design, install, and operate the best adapted system or combination of systems at each specific dam project. And spill is likely going to be part of the system at a lot of projects. That is the key to restoring naturally self-sustaining runs of salmon and steelhead in the mid-C and Snake River systems.

Sg
 

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Interesting. Does anyone think increasing the quantity of water flowing downstream through a river valley increases it's velocity? I do! Dams certainly effect things a bunch so, in a drainage as large as the Columbia/Snake the dams have to work together. It starts at the highest elevation water can be released. Forget about where it passes the dam as long as it passes the dam as quickly. If the elevation of the initial release site is 1" higher than the pool was previously, surface flows will increase, make it 2' and surface flows will increase more. Smolts are surface oriented and are either taken downstream by not resisting the current or they turn around and swim downstream (we know they do both). Surface flows are the fastest and surface flows are what they key on. When CFS (cubic feet/second) increases surface flows increase and smolts travel faster.

The Columbia system is extremely well endowed with predators, birds, pike this and that, bass, walleye all take smolts. Moving smolts out as quickly as possible always benefits the smolts. Run of the river dams still hold back water and discharge can be increased if chosen. It's a chain that must be operated as a system, top down discharge planned to the minutest detail should be expected.

Yes surface spill increases dissolved nitrogen but much has been done to reduce dissolved N2 at Columbia dams. The surface section portion of discharge always moves faster when more water is flowing through. Dissolved N2 doesn't kill many smolts any more. Faster surface flows do save some smolts because they reach the salt quicker.

Not arguing with BDD here but more water does move downstream faster than less water if the dams let it happen.
 

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Not arguing with BDD here but more water does move downstream faster than less water if the dams let it happen.
I think that what BDD was referring to is that the eight lower dams on the Columbia are all run-of-river dams, meaning they have very little live storage. So the flow discharged at each dam is largely determined by the inflow from the next project upstream.
 

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Yeah, what Sg said.

If you release all your stored water in the headwaters over a two month spring period, you'll flood Portland and then won't have any water left come September. Nature already provides the spring freshet to help juvenile fish down the river. At least on the Columbia, downstream dam operations is largely determined by what comes out of Chief Joseph dam; that is the driving force on flow. It would give everybody a warm and fuzzy feeling if there could be a coordinated effort (and there is some) but each operator is trying to maximize their own earning potential. There is a reason fly rod companies don't pool all their respective resources into a single bank account and operate business that way.

Klick you are right in that nitrogen doesn't kill many smolts...that is because it is monitored. The TDG is capped 115 and 120 percent of supersaturation (depending on tailrace or forebay) as set by the Department of Ecology. That is often the reason why more water can't be spilled as it would exceed the gas cap.

Again the more we delve in to this situation, the more we realize that there is a lot more going on than meets the eye.

I guess we could simplify things and just take the dams out and be done with it. Anybody guess how long it would take for us to reach recovery?
 
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