DESCRIPTION
Three partial barriers to fish passage remain in Pataha Creek with two being located in the City of Pomeroy and the third on private property just down stream from the USNF Boundary. The two drops in Pomeroy spill over a concrete apron into pools. The third culvert is a under sized and over steep culvert.
The Nez Perce Tribe in cooperation with the Umatilla National Forest proposes to replace two fish passage barrier culverts on Pataha Creek with bridges. Pataha Creek is a tributary to the Tucannon River and is part of the Tucannon steelhead population. Currently the two barrier culverts inhibit juvenile fish passage because of slope and velocity of flow. These barrier structures are on the end of a 47 mile journey to the headwaters. The structures impede the accessibility to approximately 3.92 miles of quality rearing habitat limiting the return of juvenile steelhead, listed under ESA, from returning from downstream over-wintering habitat to headwater habitats. Downstream habitats have been deemed as thermal barriers in summer conditions, exceeding salmonid temperature tolerances. These structures were identified in the Walla Walla Community College (WWCC) SE WA Barrier Assessment 07-1881 (G. Anthorn, 2009) and CTUIR Barrier Assessment of Pataha Creek (E. Hoverson, 2010). WWCC has provided stream cross section measurements and input on restoration options and techniques. The project envisions the removal of the two culverts, design and construction of two replacement bridges and modification or removal of log weirs below each culvert.
