Olalla Creek and Tributaries Fish Passage and Enhancement Project

Located in the Olalla Creek Watershed, the Olalla Creek and Tributaries Fish Passage and Enhancement Project successfully removed two barriers to fish passage and replaced them with structures designed to facilitate aquatic organism movement. In the summer of 2022, PUR, BLM, and Kevin Saylor Excavating installed one fish-friendly crossing on Old Lane Creek and another on Bushnell Creek. Both stream crossings now provide OC coho and other native fish with unimpeded access to rearing and spawning habitats upstream. Unfortunately, a combination of staff turnover and rising contractor costs hindered the completion of the large wood placements and willow planting. PUR will continue to work with private landowners in the Olalla Creek Watershed to implement large wood placement once additional funding is secured.

The results of this restoration project are expected to benefit all aquatic species present in Olalla, Byron, Bushnell and Old Lane Creeks through large wood placement, willow planting and replacing two failing culverts. Planting of willow wattles will help to prevent further soil erosion, help with bank stabilization, provide shade, stream roughness and help to lower turbidity levels. As they grow, they will create cover for fish to hide from predators and will provide a food source for juvenile fish. As more food is made available for juvenile salmonids, they will become larger and their survival rate greatly increases. Restoring fish passage in Bushnell and Old Lane Creeks will open up high- medium intrinsic potential habitat for fish. This is critical habitat for the recovery of OC coho salmon and steelhead. Fish habitat structures are designed to improve summer and winter instream habitat conditions because there will be a substantial increase in cover habitat and through time more pools will become available as the logs induce scour and deposition. Residual pool depth will increase, and water temperatures will decrease as a result of increased hyporheic water retention in the floodplain. Coarse substrate will accumulate and begin to create quality spawning riffles. The structures will also provide cover for juvenile salmonids and other native fish species.