Project Objectives Improve upstream passage for ESA-listed steelhead trout and bull trout Increase sediment transport through reach which will improve channel stability (reduce erosion) Enhance BPA fish passage investments at Westland Dam Improve fish habitat and riparian habitat in Westland Ramos project reach. Retain and improve diversion capacity
Progress to-date Bedload and hydraulic studies have been completed. 30% design drawings are complete. Have had series of meetings with technical work group and stakeholders to refine project. Original concept of improvements to Feed Dam have changed significantly to ensure the project does not change existing operations and increase O&M costs. Drafted BE and HIP documents.
Fish Passage at Feed Dam Factors limiting fish passage Fishway Hydraulics Full crest spill at all flows False attraction
Feed Dam Fishway Hydraulic Drop at inlet to fishway is approx. 4 feet at low flows (160 cfs). Agency criteria is 1 foot.
(The Feed Dam is) the only significant barrier to upstream migrants…under adequate flow conditions. Reconstruction in the form of a full channel fishway or dam removal are likely the best options for upstream migrants at this facility. [Contor et al., CTUIR 1997] 100 80 60 40 20 0 1995-96 1994-95 1993-94 Summer Steelhead Mean Passage Times Spring Chinook Mean Passage Times 1996 1995 1994 Westland Feed Stanfield
Bedload Transport Issues Current bedload transport regime impairs fish habitat through Poor channel form Poor channel stability Degraded riparian area
Findings of Bedload Study Flows approaching the bankfull stage are required to transport sediment in the study reach. Modifications to the Westland Dam will increase sediment transport capacity, particularly important for the range of flows within the bankfull, or channel- forming flows.
Findings of Bedload Study Dam notching will not influence the erosion and deposition characteristics of the river for flows exceeding about 10,000 cfs (6-yr event). Modifications to Westland Dam are not likely to adversely affect channel form downstream of the dam. Modifications to Westland Dam will have favorable effects in the reach between the dams by improving capacity to transport sediment within the range of channel-forming flows.
Project Proposal for Westland Dam Two rubber bladder dams are proposed at Westland Dam to facilitate bedload transport past dam
Project Schedule Plan and select preferred alternativeApril 1999 Engineering feasibilityJanuary 2000 Sub-basin stakeholder consensusDecember 2000 Final design and permittingNov 2003 - October 2004 ImplementationJuly - September 2005 Develop and implement monitoring plan 2004 - ongoing
Expected Results Enhance Fish Passage Eliminate barriers to passage at all flows Minimize migration delays Improve Bedload Transport Substantially reduce in-channel maintenance Initiate conditions for channel stability Facilitate riparian recovery Maintain irrigation diversion capacities