Appendix D | Fish Passage Presentation to Ad Hoc Ad Hoc Committee Meeting | October 2, 2019 Potter Valley Project 1 Fish Passage Options
2
Scott Dam 3
Cape Horn Dam 4
Fish Passage Working Group ´ Charge: The Fish Passage Working Group (FPWG) is developing information and recommendations on fish passage for the 5 Potter Valley Project Ad Hoc Committee. The FPWG is composed of Potter Valley Project stakeholders charged with identifying a prioritized list of conceptual-level passage options that would meet three fish passage objectives for targeted anadromous fish species beyond Cape Horn and Scott dams, located within the upper mainstem Eel River, California. If these fish passage objectives are achieved, recommended fish passage options will promote the recovery and long-term viability of currently depressed fish populations in the Eel River. The FPWG strives to identify fish passage options that meet the following objectives for each targeted fish species: 1. Population viability of upper Eel River anadromous fishes: § Viable Fish Population (VFP)Concept: abundance, productivity, spatial structure, and diversity. 2. Access to abundant high quality habitat: Access to sufficient habitat quantity and quality to complete essential life stages and § promote long-term population viability. Avoid exposing fish to low quality habitat that harbors introduced predatory fish § species . 3. Functional fish passage: § Safe, timely, reliable, and effective upstream and downstream passage. § Fish passage options that minimize stress, injury, delay and mortality ~ while maximizing efficiency.
Approach 6 1. Developed conceptual passage scenarios with options . 2. Developed a Passage Scoring Matrix. 3. Refined passage scenarios with detailed assumptions for each option . This provided the “fish passage scorers” a defined concept for each passage option. 4. Scored options independently and collectively as a group. 5. Reviewed and discussed trends in the scores. 6. Documented assumptions, unknowns, areas of agreement and diverse perspectives.
Fish Passage Scenarios 7 1 Fishway at 2 Trap & 3 Partial Scott 4 Remove Scott Existing Scott Haul Dam Dam and Modify Dam Options Removal Cape Horn Dam 1. 1.1 1 Semi- 2. 2.1 Tr Trap & 3. 3.1 Lo Lower Scott 4. 4.1 Re Remove Scott Na Natural, Low- Ha Haul, Van Dam to 80 Da 80’ – Meet Dam and Modify Da Gradient Bypass ss Arsd sdale to Ca Cape Horn Dam PVID demand and Channel Ch Scott Dam Sc environmental flows 4. 4.2 Re Remove bot oth Options 1.2 Original 1. 2. 2.2 2 Trap & Scott Dam and Sc Me Mead & Hunt Ha Haul, at Sc Scott 3. 3.2 Lower Scott Ca Cape Horn Dam (M&H) Fish (M sh Dam Da Da Dam to 50’ – 1) With Diversion La Ladder Retain (provides another accumulated baseline for flows 1.3 Modified 1. sediment and fish) M&H Fish sh Ladder La 2) No Diversion
Scenarios & Options 8
1. Fishway at existing Scott Dam 9
1.1 - Semi-Natural, Low-Gradient Bypass 10
1.2 and 1.3 - M&H Fish Ladder 11 1.2 M&H Fish Ladder: 1.3 Modified M&H Fish Ladder: Taller exit gallery • Downstream • migrating fish can use extended fish ladder/ exit gallery
2. Trap & Haul 12
2. Trap and Haul 13 2.1 - Trap at CHD Release at tributary 2.2 – Trap at SD Release in middle of reservoir
3. Partial Scott Dam Removal 14
3. Partial Dam Removal 15
4. Dam Removal / Modification 16
4. Remove SD, Remove/Modify CHD 17
Scoring the Options 18
Fish Passage Scoring Matrix|Example 19 SCORING APPROACH ESSENTIALS ü Clearly define criteria parameters and option assumptions ü Score independently from other options ü Document range of scores ü Take detailed notes on assumptions, unknowns, and diverse perspectives
Fish Passage Scenarios & Options Table | Example 20 Link to Table
Scoring Key (see Scoring Passage Matrix for complete parameter definitions) 21
Results: Averages ~ HAPPY! 22
Results: Ranges ~ Uncertainty….. 23
Results: Averages and Ranges ~ Non-Biological 24 (e.g., Ops and Engineering Feasibility) Averages Ranges
Results: Important Factors for Salmonids 25
Preliminary Trends from the Scores ´ Dam removal benefits all species and life stages evaluated. However, 26 without other water supply options, may not satisfy two-basin solution. ´ Upstream passage options available for adult salmonids (juveniles?) and lamprey (with varying long-term biological viability), but success likely achievable. ´ Different perspectives on value of Scott Dam releases during dry season and associated water quality conditions downstream. ´ Downstream passage challenges for both salmonids and other species (lamprey) of interest à Likely most limiting factor for fish passage options that retain Scott Dam ´ Engineering passage with aging infrastructure may be major challenge. ´ Assumes Cape Horn Dam / Van Arsdale Fish Station meet NMFS/CDFW standards.
Looking Forward 27 ´ Integrate work with Water Supply Working Group ´ Issues requiring further investigation and/or additional expertise: ´ Downstream passage options ´ Non-biological factors ´ Alternative flow schedules ´ Cape Horn Dam conditions (e.g., flow Rx’s) ´ Other non-passage factors described in report
Suggested Studies 28 ´ Flow Rx’s associated with desired water quality and habitat conditions downstream of Scott Dam ´ Fish production and life cycle modeling ´ Predatory fish suppression techniques ´ Fish behavior / response to reservoir habitat conditions
For Reference: 29 Other Options / Equipment
Lake Pillsbury Water Surface Elevations 30
Trap & Haul – Example Design 31
Fish Weir Example 32 Weir at entrance to a fishway (Nimbus Hatchery fish weir/ladder)
Surface Spill Bypass Example for Outmigration (Wanapum Dam, Columbia River) 33
Floating Surface Collector Concept 34 Upper Baker Lake Floating Surface Collector
Guide Nets 35
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