Fish screens and fish passage were identified in the Walla Walla Subbasin Plan as critical limiting factors that must be addressed to achieve recovery of ESA-listed Mid-Columbia steelhead and bull trout and ensure the success of reintroduced spring Chinook salmon in the Walla Walla Basin.  Consistent with the recommendations of the Subbasin Plan, Gary James, CTUIR Fisheries Program Manager, proposed under 1996-011-00 the design and construction of adult passage and juvenile screening facilities at the Old Lowden (OLDC) diversion located at RM 29.3 and the Bergevin-Williams (B-W) diversion located at RM 31.6, both of which are located on the Walla Walla River.  Project 1996-011-00 was subsequently combined with 2 other capital projects into 2007-396-00.

The two irrigation diversions being addressed have a negative effect on adult anadromous fish passage during the irrigation season when heavy equipment is used to push up temporary gravel dams to divert water from the Walla Walla River into the Old Lowden ditch and Bergevin-Williams ditch for irrigation.  They also have a negative effect on juvenile anadromous fish survival due to the use of non-compliant fish screens.  We determined in our feasibility study conducted by HDR - FishPro in 2008 that consolidation of the OLDC and B-W diversions with the state-of-the-art Garden City/Lowden 2 diversion (BPA funded project sponsored by CTUIR) which was constructed in 2000 is the most efficient and effective option available.  The upgraded diversion constructed under this contract will be married with a pipeline project, scheduled for construction in the Nov 2009 - March 2010 time frame, which will save an estimated 4.81 cfs of water lost to conveyance and increase instream flows for fish.

The project constructed under this contract will be in accordance with plans and specifications prepared by HDR-FishPro under contract 36326 which are available as a PISCES attachment.