Salmon survey confirms major habitat breakthrough in Auburn Ravine

A fall salmon survey conducted in Auburn Ravine in late November confirmed that Chinook salmon are now accessing upstream spawning habitat that had been blocked for nearly a century, marking a major milestone for local restoration efforts. Friends of Auburn Ravine volunteers surveyed the creek on Nov. 22 and observed 52 live fall-run Chinook salmon, along with one additional fish that had already died after spawning, according to James Haufler, a board member with the nonprofit. "The big thing about that particular survey is that all the salmon that came upstream this year made it past what used to be called Hemphill Dam," Haufler said. "That's now actually a fish passage site." For nearly 100 years, the Hemphill Dam blocked almost all salmon attempting to swim upstream in Auburn Ravine. In wet years, only an estimated 7 to 10 percent of fish were able to reach upstream spawning areas, while in drier years none made it past the barrier. The dam was removed in fall 2022 and replaced with a modern water diversion system known as a roughened rock ramp, which creates a gradual, "nature-like" slope that allows salmon to migrate upstream while maintaining irrigation water deliveries through the Hemphill Canal. "That project was something a lot of folks had been lobbying for many years, and it finally got done in the fall of 2022," Haufler said. "The very first year after it was put in, we had good passage. The next year, we had good passage again. But this is the first year that all the salmon that came in actually went past that old blockage." The project was managed by the Nevada Irrigation District and completed before the first major rains of fall 2022. When creek levels rose, salmon began migrating into Auburn Ravine from the Sacramento River, with movement documented by salmon cameras operated near downtown Lincoln. Before the dam was removed, salmon were largely limited to about two miles of spawning habitat between downtown Lincoln and the dam site. With the new fish passage in place, salmon now have access to eight miles of streambed upstream. "That's basically a four-times improvement over what they had before," Haufler said. The Nov. 22 survey involved 25 volunteers working in pairs for safety. Survey teams covered the creek from Lincoln upstream past Gold Hill Road near the Newcastle area. "We had a bunch of people out all the way from Lincoln going up past Gold Hill Road looking for salmon," Haufler said. "They saw a whole bunch of salmon, and that was really good news." Haufler said Friends of Auburn Ravine intentionally reports only fish that are directly observed rather than estimating totals. "We report what we've got proof of," he said. "We always say we saw this many, probably some more, but we're not trying to hype the numbers. We just want solid facts on file." Friends of Auburn Ravine has also operated a stationary salmon camera in downtown Lincoln for about a decade. While the camera provides valuable documentation during clear water conditions, muddy flows can limit visibility. This year's run appeared to peak early. After heavy rains in early November triggered migration, Haufler said no additional salmon were observed after Nov. 23. "That's odd," he said. "Usually, we see some come up later in November, sometimes December or even January. We didn't see the stragglers this year." While upstream passage has improved dramatically, downstream migration for juvenile salmon remains a concern. Young salmon begin moving downstream between February and June, often encountering seasonal flashboard dams used for agricultural irrigation west of Lincoln. "When those boards go in, some of them are six feet high, some eight or 10 feet high," Haufler said. "The babies get into the pool behind the dam and they don't feel the current anymore. Their instinct is to go with the flow." Some diversion sites have been improved with fish screens and modified structures, including screens designed to prevent juvenile fish from entering irrigation canals while allowing water deliveries to continue. Additional projects are still being pursued. "One of our main efforts right now is improving the downstream migration," Haufler said. "If we can solve that so more baby fish get out to the main river, then over time you're going to see more fish coming back." Based on current conditions, fisheries experts believe Auburn Ravine could support larger salmon runs if migration continues to improve. "I've talked to Fish and Wildlife and National Marine Fisheries folks," Haufler said. "They say if you had 350 fish in some years before, you're going to get that more consistently if you've got good upstream and downstream migration." Friends of Auburn Ravine works alongside its sister organization, Save Auburn Ravine Salmon and Steelhead, and relies heavily on volunteers for surveys, monitoring and annual creek cleanups. "It's a beautiful creek," Haufler said. "It's a community resource."