AQU 18 – APPENDIX G A CONCEPTUAL FOUNDATION FOR THE MANAGEMENT OF THE LEWIS RIVER SALMONID POPULATIONS Merwin Hydroelectric Project, FERC No. 935 Yale Hydroelectric Project, FERC No. 2071 Swift No. 1 Hydroelectric Project, FERC No. 2111 Swift No. 2 Hydroelectric Project, FERC No. 2213 June 24, 2003 Prepared for PacifiCorp Portland, Oregon and Public Utility District No. 1 of Cowlitz County Longview, Washington Prepared by George Gilmour, Meridian Environmental, Inc. Kathy Dubé, Watershed GeoDynamics Jim Lichatowich, Alder Fork Consulting PacifiCorp / Cowlitz PUD Lewis River Hydroelectric Projects FERC Project Nos. 935, 2071, 2111, 2213 TABLE OF CONTENTS 4.18.5 Results and Discussion ............................................................................................1 4.18.5.1 Conceptual Foundations – What are They and Why are They Important?.................................................................................................1 A Basin-wide Conceptual Foundation ......................................................3 4.18.5.2 The Lewis River as a Natural-Cultural System ........................................5 Natural-Cultural Systems ..........................................................................5 Lewis River Basin Natural Attributes .......................................................8 Cultural Attributes.....................................................................................9 4.18.5.3 Historical and Current Habitat Forming Processes.................................29 Flow.........................................................................................................30 Sediment..................................................................................................36 Large Woody Debris ...............................................................................39 Riparian Habitat ......................................................................................40 Water Temperature..................................................................................43 Nutrients..................................................................................................49 Aquatic Habitat Connectivity..................................................................50 Aquatic Habitat Conditions.....................................................................53 4.18.5.4 Historical and Current Fish Assemblages...............................................59 Historical Assemblages...........................................................................59 Current Assemblages...............................................................................62 4.18.5.5 Historical and Current Genetic Structure and Life History Diversity..................................................................................................83 Genetic Diversity.....................................................................................84 Life History Diversity .............................................................................95 4.18.5.6 Decadal Climate and Ocean Productivity Fluctuations ........................104 4.18.5.7 Lewis River Regulatory / Policy Context .............................................105 Laws and Treaties..................................................................................105 Policies and Plans..................................................................................109 What Trumps What? .............................................................................111 4.18.5.8 A Conceptual Foundation for the Management of the Lewis River Salmonid Populations. ................................................................112 Statement 1............................................................................................112 Statement 2............................................................................................114 Statement 3............................................................................................115 Statement 4............................................................................................115 Statement 5............................................................................................116 Statement 6............................................................................................117 4.18.5.9 Recommendations to Guide Future Fish Management.........................117 Recommendation 1................................................................................117 Recommendation 2................................................................................117 Recommendation 3................................................................................118 Recommendation 4................................................................................118 06/24/03 2002 Technical Report - Page AQU 18 Appendix G-i \\Neoserver\disk1\Projects\Lewis River\Final Tech Reports 04-04\04.0 AQU\AQU 18_Appendix G (concept found).doc PacifiCorp / Cowlitz PUD Lewis River Hydroelectric Projects FERC Project Nos. 935, 2071, 2111, 2213 TABLE OF CONTENTS (CONTINUED) Recommendation 5................................................................................118 Recommendation 6................................................................................119 Recommendation 7................................................................................119 Recommendation 8................................................................................119 4.18.5.10 Schedule..............................................................................................119 4.18.5.11 References...........................................................................................120 LIST OF TABLES Table 4.18-1. Summary of Lewis River Hydroelectric Projects effects on aquatic resources and water quality........................................................................12 Table 4.18-2. The average number of salmon and steelhead harvested in the Lewis River recreation fishery based on punch card returns to WDFW.......................................................................................................25 Table 4.18-3. Summary of streamflow statistics for Lewis River stream gages. .............35 Table 4.18-4. Average annual sediment input to selected Lewis River sub-basins under background and current conditions..................................................37 Table 4.18-5. Preferred temperature ranges, and upper lethal temperature ranges for various life stages of resident and anadromous salmonids found in the Lewis River basin. ...........................................................................43 Table 4.18-6. Maximum of daily maximum, minimum of daily minimum, and 7-day running mean of daily maximum water temperatures by site..........45 Table 4.18-7. The total number of fish, and percent of each species salvaged in the Swift canal compared with screw trap catch results. ...........................53 Table 4.18-8. Current aquatic habitat metrics in measured stream reaches in the Lewis River watershed...............................................................................55 Table 4.18-9. The length and area of potentially accessible anadromous fish habitat, and the percent of total accessible habitat in the 3 reaches of the North Fork Lewis River upstream of Merwin Dam. .......................58 Table 4.18-10. Length of potentially accessible anadromous fish habitat and the percent of total accessible habitat in the three reaches of the North Fork Lewis River upstream of Merwin Dam.............................................59 Table 4.18-11. Adjusted EDT-based historical production potential estimates for habitat located above Merwin Dam. ..........................................................60 Table 4.18-12. Lewis salmon and steelhead run reconstruction for above-Merwin production. .................................................................................................61 Table 4.18-13. Fish species present in the Lewis River hydroelectric project area..........63 Table 4.18-14. Current WDFW fish production goals for the Lewis River basin............66 Table 4.18-15. EDT estimates of adult anadromous fish production potential under current (patient) conditions in the Lewis River basin above Merwin Dam. .............................................................................................70 Page AQU 18 Appendix G-ii - 2002 Technical Report 06/24/03 \\Neoserver\disk1\Projects\Lewis River\Final Tech Reports 04-04\04.0 AQU\AQU 18_Appendix G (concept found).doc PacifiCorp / Cowlitz PUD Lewis River Hydroelectric Projects FERC Project Nos. 935, 2071, 2111, 2213 LIST OF TABLES (CONTINUED) Table 4.18-16. Releases of out-of-basin coho salmon stocks in the Lewis River from 1963 through 1992. ...........................................................................72 Table 4.18-17. Peak kokanee spawner counts in tributaries to Lake Merwin, 1978 to 1982. ......................................................................................................81 Table 4.18-18. Tiger muskellunge plants into Lake Merwin............................................83 Table 4.18-19. Samples of lower Columbia River spring and fall chinook salmon used in the NMFS status review. ...............................................................87 Table 4.18-20. Samples of Columbia River coho salmon used for genetic analysis in the NMFS status review.........................................................................89