Something entirely new: Using dams to save salmon
In the Yakima Basin, irrigators and the Yakama Nation are investigating how reservoirs can be used to create artificial currents that mimic natural ones
By Nathan Gilles. December 15, 2022. Columbia Insight
Swimming in a pool of slow-moving water surrounded by swift currents, a roughly two-foot-long coho salmon appears to be assessing her next move.
Ahead of her is a low spot where the pebbly rocks lining the stream bed peak to the surface as the water rises before disappearing again as the water drops with the current.
The difference in water depth is subtle—no more than a couple of inches—but this expert at swimming upstream seems to notice. She waits for the right moment to cross the shallows obstructing her journey.
It’s November in central Washington state’s Yakima River Basin on the eastern edge of the Cascade mountains.
Much of the lower basin falls well within the mountain range’s rain shadow and is dominated by grasses, sagebrush and irrigated agriculture.
But here in the higher elevations of the upper basin I’m surrounded by forests of green firs, cedars and pines.
The cool fall weather has yellowed the leaves of the maples, aspens and cottonwoods. And the needles of the larches, the region’s native deciduous conifers, are showing the rich ocher of their autumn color.
The stream in front of me, the one with the patient coho, is flowing fast. But it shouldn’t be. The annual fall rains haven’t arrived yet.
This small stream, aptly named Little Creek, should be bone dry.
But this oddity is exactly why I’m here. Little Creek could hold a glimpse into a hopeful future, one in which salmon can weather decades if not centuries of climate change.
This future will require a combination of human ingenuity and cooperation. It’s a future that blurs the line between natural and artificial.
I’m skeptical, but I’m willing to be surprised.
Nathan Gilles 