Icicle Creek is the largest tributary of the Wenatchee River subbasin. Stream conditions, floodplain connectivity and riparian habitat below the wilderness boundary have been impacted by road construction, campgrounds, timber harvest, private development, fish passage impediments and water withdrawals by irrigation districts, the city of Leavenworth, the Leavenworth National Fish Hatchery (Leavenworth NFH) and private parties. (Andonaegui, 2001; Berg and Lowman, 2001). 

Local technical experts and NOAA-Fisheries have identified assessment of passage at the Icicle Creek boulder field (RM 5.6) as a priority action. There are more than 26 main-stem miles of potential fish habitat available above the boulder field. Ecosystem Diagnosis and Treatment (EDT) and Interior Columbia Technical Review Team (ICTRT) intrinsic potential models predict very large increases in capacity for steelhead with access to the upper Icicle.  The habitat above the boulder field is more than 20 miles of virtually undisturbed US Forest land and wilderness.

TU recently completed a Boulder Field passage assessment, convened technical experts and stakeholders, and developed preferred alternatives to achieve passage at two identified impediments: An area around a large boulder (aka the Anchor Boulder) and an Irrigation Diversion Dam at low flows. 

TU has utilized local expertise, regional fish passage engineers and other regional scientists to identify fish passage impediments, anthropogenic impacts on passage as well as site appropriate fish passage alternatives.  Further, TU has engaged key watershed stakeholders in this process, identified and worked to address other data gaps related to fish passage enhancement on this project.  

This project resolves the longstanding question of the potential for fish passage above the Icicle boulder field, which is one of the most significant fish passage questions in the Wenatchee Basin and the third highest priority in the basin. TU secured research funding, retained top experts in the field, convened key stakeholders and regional experts and released in June of 2013: The Icicle Creek Boulder Field Passage Assessment.

Jason Hatch, project manager, TU Washington Water Project

jhatch@tu.org

Jason Hatch, project manager