As part of the Yakima-Klickitat Fisheries Project (YKFP), the Yakama Nation proposed developing hatchery strategies to increase harvest levels, natural spawning abundance, and spatial/temporal distribution of summer- and fall-run Chinook and coho salmon in the Yakima Subbasin. The YKFP focused on enhancing existing stocks of anadromous fish in the Yakima and Klickitat river basins while maintaining genetic resources and reintroducing stocks formerly present in the basins.
A major challenge in these basins is the limited water supply during summer and fall and the need to develop innovative ways to re-use water. Hatchery production goals include 2.2 million fall Chinook sub-yearlings and 500,000 coho yearlings at the existing Prosser hatchery; 250,000 each of summer Chinook yearlings and sub-yearlings at the existing Marion Drain hatchery (on re-use); and 500,000 coho sub-yearlings and 200,000 coho yearlings at the new Holmes Ranch facility (on re-use).
The Yakama Nation contracted with McMillen Jacobs Associates (McMillen Jacobs) to complete a Step 1 Master Plan and supporting tasks:
- Master Plan: The Step 1 Master Plan was approved through the Northwest Power and Conservation Council (NPCC) Independent Scientific Review Panel (ISRP) process. The Master Plan addressed modifications to existing hatchery facilities at the Prosser and Marion Drain hatcheries, development of a new hatchery at Holmes Ranch, alternatives for adult trapping improvements at Sunnyside Dam, and hydraulic/hydrologic analysis. McMillen Jacobs worked with the Yakama Nation fisheries staff to refine project goals and to confirm biological criteria and related water supply needs in order to develop preliminary design parameters. Because of the limited water supply during summer and fall, the team studied ways to maximize the use of available groundwater supplies, construction phasing, and bio-security during construction.
- As-Built Mapping: Survey and base mapping of the existing Prosser and Marion Drain hatcheries and an off-site water supply corridor pinpointed undocumented improvements, defined elevations to develop a hydraulic profile, identified underground supply and drain pipe routes, and provided data for a potential new water supply pipeline route and screened intake.
- Acclimation Sites: We conducted an alternatives analysis of potential lower river sites for acclimation ponds for sub-yearling fish, and adult holding and spawning facilities to enhance fall Chinook salmon populations in the lower Yakima River.
- On-Call Services: Ongoing design and other work efforts following completion of the Step 1 Master Plan.