The last thing you want in a federal courtroom – any courtroom – is a testy judge. But that is precisely what federal scientists confronted in the latest legal fight over the tiny Delta smelt, which needs fresh water to thrive in its increasingly saline marshy habitat.

“Testy” may be too kind a description. Fresno U.S. District Judge Oliver W. Wanger, who steps down this month after more than two decades on the bench, excoriated the scientists – one from the Bureau of Reclamation, the other from the Fish and Wildlife Service – for what he characterized as deliberately deceiving the court with inconsistent testimony. The FWS scientist, he said was a “zealot;” the other was ”untrustworthy as a witness.”

“I have spent my life in courtrooms. This is my life. I have never seen anything like this,” he thundered last week, according to a transcript of the proceedings.

Wanger didn’t stop there. His comments, covering page after page of the court transcript, can accurately be described as a “rant” or a “diatribe.” His pique apparently was enflamed because the scientists, he said, “accuse the court of using the wrong legal standards, not, in effect, knowing the law, misapplying it and not understanding it.”

Wanger, in language that was unusual even for California courtrooms, then went on at length dissecting the scientists’ testimony and announcing a finding that the government acted in bad faith. It was an odd, sustained tongue-lashing.

The FWS’ Jennifer Norris, he said, “has not been honest in this court. I find her to be incredible as a witness. I find her testimony to be that of a zealot. And I’m not overstating the case. I’m not being histrionic. I’m not being dramatic. I’ve never seen anything like it. And I’ve seen a few witnesses testify.”

Norris, he added, “Never varies from her answer, because she is a true believer. And she never – there is nothing that will shake her belief. There is nothing that will move her to an answer except that justifies the result and the end that is achieved.”

As for the Bureau of Reclamation’s Frederick Feyrer, he showed “absolute incredibility” and “absolute unreliability,” and “finally, the most significant finding, the court finds him to be untrustworthy as a witness,” Wanger stated.

Norris and Feyrer did not comment on Wanger’s statements, but the Interior Department through a spokesman defended the scientists’ work, calling it “consistent and thorough.”

“The Department of the Interior has been diligent responding to the varying matters before Judge Wanger’s court, including in the formation of the delta smelt biological opinion, first in 2005, which was then rewritten at the judge’s request in 2008. We stand behind the consistent and thorough findings by our scientists on these matters and their dedicated use of the best available science,” said spokesman Adam Fetcher.

The underlying issue of the case is the government’s plan to tap the Sacramento River to retain some fresh water supplies in the Delta, rather than let it be shipped south, a move that by some estimates could cut water to San Joaquin Valley irrigation districts by some 300,000 acre-feet, perhaps more. Wanger blocked the move, at least temporarily.  A detailed description of the issue can be found here.

The Delta, an estuary fed by several rivers, is at the heart of California’s water system and provides about half the state’s drinking water.

Ed’s Note: This story originally appeared in California Water Wars, www.calwaterwars.co.