Background
The Catherine Creek system contains three ESA listed species: Snake River spring chinook and summer steelhead, and bull trout.  All of these populations are severely depressed from historic levels.  Catherine Creek was rated one of the highest habitat restoration priorities in the Grande Ronde Subbasin Plan.  Elimination of passage barriers is one of the highest priority actions.

There have been numerous local Watershed Analyses, Biological Assessments completed by the U.S. Forest Service, Oregon Department of Fish and Wildlife, Grande Ronde Model Watershed Program and local groups within the Grande Ronde Basin.  The most relevant to fish passage issues in Catherine Creek are Stream and Riparian Conditions in the Grande Ronde Basin, Huntinton 1993 and The Grande Ronde Model Watershed Action Plan 1994.  Both of these plans identified fish passage at irrigation diversion structures for this reach of Catherine Creek as factors limiting salmon production.  Huntington, p 4.  Grande Ronde Model Watershed Program Action Plan, p 27.

The regional plan is the Grande Ronde Subbasin Plan (NPCC 2004) and Grande Ronde Supplement (NPCC 2004).   Much of the prior assessment information, as well as personal knowledge of the Basin fish biologists, was incorporated into these plans.  Restoration priorities were established through the planning process by the Grande Ronde Subbasin Planning Team. These documents identify Catherine Creek as the number two priority geographic area for Snake River ESA listed spring chinook.  Catherine Creek and the Upper Grande Ronde chinook populations were predicted (EDT analysis) to experience “dramatic” population increases as a result of habitat restoration work.  Although the plan did not identify individual passage barriers (lack of data); fish passage, in high priority watersheds, has always been considered one of the key issues where blockages are identified.  The State Diversion, at low flows, can impede adult chinook migration and most certainly blocks juvenile upstream passage.  

The Grande Ronde Supplement identified key habitat quantity and temperature as factors limiting chinook survival in this reach of Catherine Creek, Table 3-1, p 15.  The inability  of bull trout, and juvenile steelhead and chinook to pass the State Diversion at low flows when water temperatures are warming limits access to better habitat and cooler  water  upstream of the site.

The State Diversion is a full channel-spanning concrete wall with about a two-foot drop during extreme low flow.  Check boards are used during low flow to divert water into the irrigation ditch, creating a three foot drop.  The structure may impede the latter part of the adult chinook migration, depending on when the boards are placed, the timing of the run and the stream flow.  The structure does not meet fish passage standards (6”drop) and is a complete impediment (upstream) to juvenile steelhead and chinook, and bull trout at low flows.  

Project Objectives are:
•Reestablish year-around passage for all life stages of native fish, with emphasis on ESA-listed summer steelhead, spring chinook and bull trout.
•Meet 6” passage criteria

Proposed Actions
The project will be implemented on Catherine Creek at the State Diversion, approximately RM 20.  Construction is scheduled during the in-water work window July 1 – August 15, 2007.  The proposed project was reviewed by the GRMW Technical Committee and approved by the GRMW Board of Directors for implementation in 2007.

The GRMW will be the project sponsor and will coordinate all aspects of project management including agency and landowner coordination, ESA consultation, permitting, cultural resource activities, contract administration, fiscal management, subcontracting and construction oversight.

Preliminary design, final design and cost estimate will be done by professional engineering staff of the Oregon Department of Fish and Wildlife Fish Screening and Passage Program in Salem.  The proposed action is to install a fish a ladder on the south bank.  The off-channel concrete ladder design was selected to minimize potential damage from debris and ice flows known to occur in Catherine Creek, and to minimize the potential for debris to plug the ladder.  An in-channel structure was considered but would also be prone to block ice flows and cause flooding.  The design team briefly discussed metal fabrication of a structure, as a least cost alternative to concrete, but felt concrete would be much more durable.

Partners are BPA, ODFW and the irrigators.   Additional cost-share funds have been acquired from the Oregon Watershed Enhancement Board.  BPA and OWEB funds will be used for construction.  The irrigators will be responsible for maintenance and operation.