A rush of water may have scoured away threatened wildlife in Portland’s Forest Park

The Portland Audubon is worried that a large release of drinking water into a tributary off of Balch Creek may have washed away delicate populations of salamanders, frogs and fish.

For 100 years the society has been repairing and looking after the unnamed tributary, which they unofficially call Bone’s Creek , which runs through Portland’s Forest Park. Audubon conservation director Bob Salinger said that at this time of year the creek is almost dry. But on Monday it was washed through by a wall of water.

“A lot of water rushing through a creek suddenly like that can scour the creek. It creates huge sedimentation and siltation. It can wipe out wildlife populations like invertebrates and amphibians,” he said. “You never want to have that sudden blast of water going through your ecosystem like that. That absolutely needs to be prevented.”

Andrea Watson with the Tualatin Valley Water District said one of their water storage tanks was schedule for re-painting. So they dechlorinated the estimated 150,000 gallons it contained, then slowly drained it from 8 a.m. to 2 p.m.

“I wouldn’t exactly call this typical,” said Watson. “We don’t drain water generally, we try to use it as it’s intended, ... for drinking water or fire protection. But there are times when you need to maintain, or you need to clean a reservoir ... and this is the typical procedure.”

Watson said the water district does not need a permit for such releases.

“It’s not that we don’t care. We do care,” said Watson. “If they had reason to believe that this was not a good time, then ... we would have loved to hear from them in advance.”