Poley-Allen Fish Passage Project

The project site is located at a privately-owned irrigation diversion dam on the Lostine River approximately 1 mile south of the town of Lostine, Oregon (RM 4.8), and includes the mainstem Lostine River and the Poley-Allen irrigation diversion dam and intake. Prior to restoring the diversion, the structure was an upstream passage barrier for ESA listed spring Chinook Salmon, steelhead and Bull Trout. Through the implemented modifications to the existing channel spanning concrete sill and concrete abutment, roughened channel installation downstream of the sill, and LWM placement in the adjacent side channel, this project maximizes year-round fish passage and diversify fish habitat for all life history stages of Bull Trout, steelhead, and Chinook Salmon, while maintaining access to irrigation water for current water rights holders. Various invasive weed species were removed in the riparian area, and willow trench planting was done on the restored streambank.

Project partners included the Grande Ronde Model Watershed and BPA.

By eliminating this partial passage barrier, adult Chinook will experience reduced migration travel times through this stretch of the Lostine River when temperatures are highest and flows are lowest. Through improving habitat conditions in the side channel adjacent to the diversion, juvenile salmonids will have additional rearing area, providing cover, greater feeding opportunities, and velocity refuge during higher flows. Through passage and habitat restoration through this reach, greater habitat connectivity will be achieved for all life stages of salmonids and aquatic species.