Project Effectiveness Monitoring in the Fender Mill Side Channel

Side channel restoration to improve juvenile salmonid rearing habitat remains a key component of the Upper Columbia Basin salmon recovery habitat enhancement strategy. Side channel restoration projects often focus on diverting main channel surface waters to create inundated off-channel habitat, either as a flow through side channel or backwater alcove. Yakama Nation Fisheries recently completed a promising new type of side channel restoration project which involved using a sophisticated groundwater collection system instead of surface water diversions to create thermally enhance side channel surface flows. Known as the Fender Mill Side Channel Restoration Project, Yakama Nation Fisheries reconnected roughly 2,000 linear feet of side channel to Methow River located between the towns of Winthrop and Mazama using a groundwater infiltration gallery.



The goal of this monitoring component of the project was to evaluate benefits and limitations of connecting side channel systems using groundwater infiltration galleries. The project evaluated how the Fender Mill side channel was used by coho, steelhead, and chinook (PCSRF funds). It also explored the potential impact the thermally enhanced flow has on growth and survival of juvenile salmonids. Metrics of juvenile growth and survival collected from Fender Mill Side Channel were compared to similar data collected by other Yakama Nation Fisheries (YNF) projects that were monitoring other recently completed restoration actions including: 1890s side channel (another groundwater fed channel), Chewuch RM 4.5 side channel (a flow through channel) and mainstem habitat in the Chewuch and Twisp rivers.



Snorkel surveys and spawning ground surveys were used to document fish use of Fender Mill side channel by season, species, and life stage. Fish growth and survival rates were measured through remote PIT tagging and subsequent recapture and detection. Restoration effectiveness monitoring also was conducted in the same side channel segment. Statistical comparisons were made between the results obtained from the Fender Mill channel and results obtained from other side channel and main-stem habitats in the Methow Basin.



A full description of the methodology, results, and discussions, including tables and figures, can be found in the “Fender Mill Side Channel Restoration Effectiveness Monitoring: Final Report”, which has been attached to this project entry.

This proposal seeks to create a monitoring project that will evaluate benefits and limitations of using groundwater to restore side channel habitat. The proposed monitoring project will detail how both target and non-target fish species actually use the restored Fender Mill side channel, and compare the effectiveness of this type of side channel restoration action towards increasing juvenile salmon growth and survival in relation to other side channel reconnections recently completed in the Methow Subbasin. Intensive effectiveness monitoring of side channel reconnection projects is now taking place throughout the region, with a specific focus on the effectiveness of recent side channel restoration actions in the Methow Subbasin. At present, three separate monitoring programs conducted by co-managing agencies are assessing fish use and response to most of the recently completed side channel treatments. However, while these monitoring programs are critical to increasing our scientific knowledge of the effectiveness of differing side channel types and restoration techniques, none of these programs are currently set up to monitor the Fender Mill side channel or the response target species might have to infiltration gallery fed surface waters.