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What may be the largest return in decades of wild fall chinook salmon to Bear Creek will get a helping hand through Medford, where a combination of drought and concrete fish barriers threaten to bog them down in downtown. State fish biologists used sandbags Tuesday to control creek flow over an abandoned sewer pipe and concrete cover exposed by erosion under Jackson Street bridge and built a fish ladder with sand bags and rocks to help boost fish over the 4-foot-tall barrier. Just to get there, however, chinook still must swim under a bridge of concrete once poured to protect cables buried beneath the creek. Erosion has eaten the gravel bed away to a point where the entire creek flows underground beneath it. Chinook were able to swim through the tunnel and jump over the exposed pipe last year. However, the water at the base of the pipe is likely too shallow this year for chinook to develop the momentum needed to launch themselves over it. The impediment threatens to halt some or even most of the fall chinook from reaching upper Bear Creek spawning grounds as far as Ashland, where they have been documented annually since 2011. “Between the jump and the low flows, we have to give them a boost to get them to Ashland,” said Dan VanDyke, Rogue District fish biologist for the Oregon Department of Fish and Wildlife. An ODFW crew spent most of Wednesday morning fashioning the ladder and stacking sand bags to funnel what water is left in Bear Creek through it as flows continue to drop through October. “We’ve got to get this done,” said biologist Ryan Battleson, who built the ladder. “The chinook are knocking on the door.” Pete Samarin, another ODFW fish biologist, said he would like to bump up Emigrant Lake water releases to Bear Creek as a way to provide better passage through October while the bulk of the run moves from the Rogue River into the Bear Creek Basin, which is a key spawning and rearing waterway for wild chinook and steelhead. A federal settlement requires the Talent Irrigation District to maintain a minimum flow of 2 cubic feet per second into upper Bear Creek for salmon habitat. But Samarin said he would like to see that doubled or tripled through October as fall chinook migrate up Bear Creek and into Ashland Creek or even Emigrant Creek to spawn. Adding 2 cfs to the releases would cost TID 120 acre-feet of water through all of October. “Four cfs is slightly better, but it’s still not good,” Samarin said. Emigrant was listed Tuesday at just 9 percent full, with about 3,554 acre-feet of water. TID Manager Jim Pendleton says he is not inclined to release more water because of already low conditions at Emigrant Lake and a need to ensure his required releases can be fulfilled. “I don’t want to support that out of Emigrant Lake,” Pendleton says. “I have to make sure I can keep going with what I got.” The short-term fixes to the fish-passage ills under the Jackson Street bridge come as biologists and others work out a long-term solution of removing the two impediments altogether. However, the Oregon Department of Transportation has balked at a quick-fix removal, saying the agency wants to see an engineering study that crafts a removal plan that does not threaten over time to erode dirt and rocks around an Interstate 5 viaduct abutment upstream in Hawthorne Park. The abutment rests on dirt and rocks and is not anchored in bedrock. VanDyke said the engineering study is estimated to cost $40,000. ODFW and a consortium of supporting groups plan to ask the Oregon Watershed Enhancement Board for that money next month. Reach Mail Tribune reporter Mark Freeman at 541-776-4470 or [email protected] . Follow him on Twitter at @ MTwriterFreeman .