The federal agencies that operate dams and sell power on the Columbia River will keep spilling water over the Lower Snake River dams next month to float young salmon downstream. They didn't want to. But with the weight of scientific opinion clearly against them, they decided to make the best of a bad thing.

The Bonneville Power Administration, the Bureau of Reclamation, the U.S. Army Corps of Engineers, and the Northwest office of NOAA had asked the federal district court to let them follow a 2010 Spring Fish Operation Plan under which they'd stop spilling water over the lower Snake River dams by May 1.

On April 19, they told the court never mind.

Given all the scientific opinion to the contrary — everyone but NOAA thought that stopping spill was a bad idea — their chance of convincing the court seemed slim.

Those agencies are, of course, the defendants in the long-running suit over the Biological Opinion issued by the Bush administration in 2008, tweaked but basically defended by the Obama Administration last year, and scheduled to make another appearance in U.S. District Judge James Redden's court next month.

Federal courts have been hammering them over biological opinions for nearly 20 years. Redden, who tossed the Bush administration's first attempt at a BiOp, has expressed strong skepticism about this one, too.

When last seen, the BiOp would have made this year's proposed spring fish operation plan the new norm: federal agencies could spill or not spill at their own discretion. The fish operation plan was basically an effor to jump the gun.

Nineteen years after Columbia and Snake River salmon populations were first listed as threatened or endangered, we're still arguing about how to get them down the river.

Needless to say, young salmon of all species — except landlocked kokanee — make their way downstream to salt water. They don't really swim down. The current sweeps them from the spawning streams to the sea — unless, that is, the river has been dammed. Then, downstream passage can be a problem.

The old river, the river that cut its way through the basalt of the Columbia Gorge, is basically gone.

All the salmon populations in the Columbia River and its tributaries evolved in (or were intelligently designed for; this doesn't require Darwin) that river. They do best when the system functions naturally, or as close to naturally as generations of dam-building permit.

Therefore, the question is how you manipulate the flows through reservoirs, through and over dams to replicate the conditions to which wild fish adapted. Beyond the obvious — screening turbine intakes so young fish aren't sliced into sashimi, minimizing exposure to slack-water predators, so they're not swallowed whole — this is largely a question of moving them downstream quickly enough so they're not saltwater fish trying to survive in a freshwater environment..

Starting in 2006, plaintiffs in the BiOp litigation have persuaded Redden to order spill at lower Snake River dams every spring. Arguably — the plaintiffs certainly argue this way — these spills have been at least partly responsible for the recent increase in salmon returns. The Fish Passage Center has compared salmon survival rates for the low water years of 2005 and 2007 — before and after the court started ordering spill — and has found that fish did better in 2007. Two years ago, Redden told the lawyers in the case, "I conclude the status quo [regarding spring spill operations] should be maintained" while the feds completed the 2008 BiOp.

This year, the feds asked the judge to change his mind. What was new? Had anything changed, or was the feds' spring operation plan a classic example of people doing the same thing repeatedly and expecting a different result?

Yes and no. What hadn't changed (what may never change) was that the usual suspects advocated the usual courses of action. What had changed was that they had acquired some new scientific data and therefore offered some new rationales.

The federal agencies argued that in low-water years, steelhead do better when they're barged. But steelhead aren't the only fish around. Even if barging does help steelhead, the Fish Passage Center has pointed out, the feds' proposal would also "increase the proportion of yearling spring/summer Chinook, fall Chinook, coho and sockeye transported. The available data indicates that transportation may be detrimental to sockeye and does not show a benefit for spring/summer Chinook yearlings or fall Chinook juveniles."

As Earthjustice lawyer Steve Mashuda points out, sockeye are the most critically endangered fish in the whole Columbia/Snake River system. They were the first listed under the Endangered Species Act in 1991. They are the symbolic red fish that had almost disappeared from Idaho's Redfish Lake.

Besides, the Fish Passage Center noted that barged steelhead tend to screw up more. In the real world, even fish make mistakes. Salmon heading upstream to spawn sometimes stray into rivers and streams where they don't belong. If a stream still has a wild population, strays can dilute the gene pool. Steelhead that have been barged downstream stray a lot more frequently than those that have not.

All in all, the Center observed that found that "spill increases reach survival, decreases travel time and increases (the smolt-to-adult ratio, which is basically the proportion of young fish that comes back to spawn)." The Center concluded that the NOAA analysis "does not provide convincing support for the BiOp to change juvenile fish passage operations."

And the Fish Passage Center wasn't alone in taking a dim view of the federal agencies' science. A February report from the Western Division of the American Fisheries Society had already cast doubt on the data supporting and the objectivity of the federal government's arguments for more barging. It had taken a more general swipe at the underpinnings of the Adaptive Management Implementation Plan that the Obama Administration had appended to the Bush BiOp. This is significant. Eliminating spill in a low-water year would seem to have been the first stab at "adaptive management."

The adaptive management plan made much of using the "best available science." The Fisheries Society scientists weren't buying it. "Rather than use a precautionary principle to protect threatened and endangered salmon and steelhead," they wrote, "the (adaptive management plan) seems to use a precautionary principle to support the 2008 Biological Opinion and to defend the status quo." Despite "repeated use of the term 'best scientific information,' " they wrote, their own group came to the conclusion that that the (adaptive management plan) does not always use the "best scientific information.”

A week later, the Independent Scientific Advisory Board, which reviews questions about fish for the Northwest Power and Conservation Council, expressed its own doubts about shutting off spill. Instead, the ISAB recommended viewing spill as the baseline, explaining that "spill more closely mimics natural situations and ecological processes than maximum transportation leads to a mixed strategy of concurrent spill and transport to conserve diversity and future potential of the ecosystem."

This wasn't a new idea. The group quoted its own report from 2008: "Finally, the perspective on spill included in ISAB Report 1999-4 deserves special recommendation in this report: 'Spill: The general principle is that all juvenile passage alternatives should be evaluated against the baseline of spill. As an avenue of hydroelectric project passage, spill more closely mimics natural situations and ecological processes than other available routes. Spill . . . should be considered the default recommendation rather than simply one of the alternatives.' ”