Tuesday May 26, 2026
Active NorCal —
For roughly eight decades, the concrete wall of the Hemphill Diversion Dam kept salmon penned in below it. Built in the 1930s, the eight-foot structure pooled water from Placer County’s Auburn Ravine and routed it through canals to nearby farms and ranches. It did its job for water users, but it also became the single biggest roadblock for migrating fish in the county.
“The dam was the most significant barrier to salmon and steelhead in Placer County,” said Gregg McKenzie, executive director of the Placer County Conservation Program.
That changed in 2022, when the Nevada Irrigation District teamed up with local groups and state and federal agencies to take the dam out. In its place went a roughened rock ramp, a low, natural-looking incline of gravel and boulders that lets fish swim over it while still diverting water into the canals.
The results came quickly. “With the old structure, only about 10 percent of the fish could get upstream. Now, we get 90 percent passage rather than 90 percent blockage,” said James Haufler, president of Friends of Auburn Ravine.
A November 2025 survey counted 42 living salmon and four egg nests in stream sections that had been off-limits for generations. Earlier DNA testing also detected Chinook salmon and Pacific lamprey upstream.
Fish now reach six additional miles of prime spawning habitat, a meaningful gain for California salmon and steelhead. As Haufler put it, “We don’t need to have battles between fish and farms.”