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, recognized fish passage issues and juvenile fish screen issues at the following locations:  1) the Old Lowden (OL) diversion at RM 29.3 on the Walla Walla River, and 2) the Bergevin-Williams (BW) diversion located at RM 31.6 on the Walla Walla River and 3) the Blalock Irrigation District (BID) diversion located at RM 5.1 on Mill Creek.   He proposed that WWCCD design and install upgraded diversions that provide for adult passage and NMFS compliant fish screens with funding provided under 1996-011-00.

Old Lowden and Bergevin-Willi... ams Diversions
     The BW and OL diversions have a negative effect on adult steelhead and bull trout 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 OL ditch and BW ditch for irrigation.  Both diversions have a negative effect on juvenile steelhead and bull trout survival due to the use of antiquated non-compliant juvenile fish screens. i'
     In 2008 BPA awarded contract CR36326 to WWCCD.  This contract provided funds for development of designs for fish friendly diversions equipped with NMFS compliant juvenile fish screens to replace the gravel push up dams at the OL and BW diversions on the Walla Walla River.  WWCCD subcontracted with HDR-FishPro and together with the irrigators determined that consolidation of the OL and BW diversions with the state-of-the-art Garden City (GC) & Lowden 2 (L2) diversion would be the most efficient and effective option available.  The L2 & GC diversion is a modern BPA funded diversion constructed in 2001.  It provides state-of-the-art features such as a pneumatic dam, a fish ladder, fish screens and air blast fish screen cleaning system.  The current BW and OL diversion project (CR210955) will consist of:  a) an irrigation water intake structure installed at the existing GC & L2 diversion,  b) a primary pump station installed at the existing GC & L2 diversion, c)  a NMFS compliant fish screen installed at the existing GC & L2 diversion, d) an air blast cleaning system incorporated in with the existing L2 and GC air blast system, e) a buried pipeline under the Walla Walla River channel to connect the new BW & OL diversion which is located on the south side of the channel to the BW & OL pipeline which will be installed on the north side of the channel immediately after completion of the BW & OL diversion and f) a telemetry system to monitor important parameters at the diversion and report water use.  In addition, there will be a booster pump station (Option 1) installed on the north side of the channel to provide water to a secondary lateral. Plans and specifications for the BW and OL diversion consolidation project and the booster pump station (Option 1) are available as a PISCES attachment.    
Benefits
     The proposed consolidation of diversions would eliminate the last two major physical fish passage barriers on the mainstem Walla Walla River in Washington – the OL and BW gravel push up irrigation diversions (gravel dams) that are presently used to divert flow into the OL and BW irrigation ditches.  This fishery benefit includes not only the permanent elimination of the two gravel dams per se but also the necessity of operating heavy equipment in the channel to construct and maintain these gravel dams.
     The proposed consolidation of diversions would also replace non-functional, antiquated fish screens at the OL and BW diversions with NMFS compliant juvenile fish screens.
Post Construction O&M
       As a result of the current BW and OL diversion project and the BW and OL pipeline project (BPA contract 49521) the irrigators on the two ditch conveyance systems are consolidating and are currently in the process of forming a non-profit corporation for the purpose of administering their affairs as they relate to the new diversion and pipeline.  With completion of the BWOL diversion and pipeline projects this newly formed corporation will take ownership and assume O&M responsibilities for both the diversion and pipeline.  WWCCD will utilize an agreement format similar to the Attachment entitled “Example of O& M Agreement for Similar Project”.

Blalock Diversion
     The Blalock irrigation district (BID) diversion, located at RM 5.1 on Mill Creek, is unscreened and, at 10 cfs, is a potential source of mortality for juvenile steelhead, bull trout and spring Chinook due to entrainment in flows diverted for irrigation.  
     In 2011 the WWCCD received a federal FRIMA (Fisheries Restoration and Irrigation Mitigation Act) grant through WDFW to develop specifications and a design for the Blalock Irrigation District (BID) diversion and fish screen.  WWCCD subcontracted with HDR-FishPro to work with the irrigators and state and tribal biologists to design a new diversion structure for the BID which meets the needs of the irrigators and complies with the NMFS juvenile fish screen requirements.   Plans and specifications for the BID diversion and fish screen project are available as a PISCES attachment.  The BID diversion upgrade project to be completed under this contract (CR210955) will consist of:  1) a concrete structure that houses fish screens and associated air blast cleaning system manifold which will be installed parallel to the flow in Mill Creek,  2)  an air compressor, pressure tank and electronic control system that will be in a weather proof shed located inside a secure fenced area owned by the City of Walla Walla.  
Benefits    
     The proposed project will provide a NMFS complaint juvenile fish screen for the largest unscreened diversion on Mill Creek.  At 10 cfs the BID diversion screen has been a high priority for WDFW for at least a decade.  
Post Construction O&M
       With completion of the BID diversion and fish screen project the board of directors will, on behalf of Blalock Irrigation District, assume ownership and responsibility  for operation and maintenance of the new diversion, fish screen and air blast cleaning system.  The signed agreement to this effect between WWCCD and the BID is included as an “attachment”.   Show More