Protecting the Best: Upper Luckiamute Mainstem Anchor Habitat Enhancement

The Upper Luckiamute Mainstem Anchor Habitat Enhancement project area lies within the timberlands of the Upper Luckiamute 6th field hydrologic unit in the northwest corner of the watershed in Polk County. Historical practices such as splash dams, log drives, logging to the water’s edge, and log removal impacted upper Luckiamute sub-basins, including the mainstem Luckiamute River. The reach represents some of the best habitat in the Luckiamute watershed and had the highest numbers of steelhead and cutthroat trout observed in the 2008 snorkel surveys. However, the streambed is scoured to bedrock in many areas, riparian conifers are absent in large sections, and there is little channel-floodplain interaction. The proposed project area is the highest priority without an active project. Resolving current and future in-stream large wood deficiencies through log placement, riparian planting, and thinning an overstocked Douglas fir plantation in the riparian management area will result in both immediate and long-term habitat benefits and restore key ecological processes throughout the reach.

The LWC identified those reaches in the Luckiamute basin that have the highest potential for recovery with a primary focus on steelhead production and secondary focus on coho and cutthroat production. The upper Luckiamute River exhibits the key geomorphological features and water quality conditions that make it ideal for steelhead. Extensive modeling, on-the-ground surveying, and communications with regional experts has revealed the upper Luckiamute River mainstem as high priority anchor habitat for federally listed winter steelhead and other sensitive aquatic species in the Luckiamute watershed. The project’s target reach (approximately 1.6 miles) is near the uppermost extent of steelhead distribution within the Luckiamute basin. Results from six years of summer snorkel surveys (2002-2003 and 2008-2011) show that the upper Luckiamute River is the most productive steelhead reach in the watershed. For example, a subset of the upper Luckiamute 6th field, including the West Fork of the Luckiamute and its tributaries and about five miles of the mainstem Luckiamute above West Fork, contained 91% of all steelhead and 45% of all the cutthroat observed in the entire Luckiamute basin (Bio-Surveys Rapid Bio-Assessment Report 2008). In subsequent survey years, steelhead and cutthroat productions rates were highest within this uppermost sub-basin (Bio-Surveys RBA Report 2011). Although present, in-channel large wood is in short supply in the project reach and upslope and adjacent large wood sources are not sufficient to provide the structural complexity the upper Luckiamute needs now to continually maintain or improve salmonid production. Large wood placement will accelerate the processes that form complex off-channel habitat and recruit and retain high quality spawning substrate, while forest enhancements will ensure those processes persist into the future. In short, the objectives outlined in this proposal are necessary to improve and maintain the critical high-quality habitat characteristics that support relatively high abundance of salmonids in the upper Luckiamute.