DISTRIBUTION AND SPAWNING HABITAT OF LATE-RUN CHINOOK SALMON First-Draft LAKE CHELAN HYDROELECTRIC PROJECT FERC Project No. 637 December 7, 2000 Prepared by: BioAnalysts, Inc. Boise, Idaho Prepared for: Public Utility District No. 1 of Chelan County Wenatchee, Washington Late-Run Chinook Salmon TABLE OF CONTENTS SECTION 1: INTRODUCTION........................................................................................1 SECTION 2: SPAWNING DISTRIBUTION OF LATE-RUN CHINOOK SALMON ..........1 2.1 Columbia River Basin.................................................................................................................................... 2 2.2 Puget Sound................................................................................................................................................... 2 SECTION 3: SPAWNING HABITAT REQUIREMENTS .................................................5 SECTION 4: ARTIFICIAL SPAWNING CHANNELS ......................................................9 SECTION 5: STREAM ENHANCEMENT PROJECTS .................................................10 SECTION 6: REFERENCES.........................................................................................11 LIST OF TABLES Table 2-1: Listing of streams with lengths less than four miles used by late-run chinook salmon in the Puget Sound and along the coast of Washington. Chinook presence from StreamNet (2000) and stream miles from Williams et al. (1975a, 1975b). ................................................................................................................. 4 Table 3-1: Summary of published information on water depth and velocity in late-run chinook spawning beds. ........ 6 LIST OF FIGURES Figure 3-1: Relationship between usable-area and stream discharge, North Nemah River (from Collings 1972). ....... 7 Figure 3-2: Relationship between usable-width and spawning flow (from Thompson 1972). ...................................... 8 First-Draft Study Report Lake Chelan Project No. 637 December 7, 2000 Page i SS/5103 Late-Run Chinook Salmon APPENDICES APPENDIX A: LIST OF STREAMS (WASHINGTON) APPENDIX B: LIST OF STREAMS (OREGON) APPENDIX C: ANNOTATED BIBLIOGRAPHY Lake Chelan Project No. 637 First-Draft Study Report SS/5103 Page ii December 7, 2000 Late-Run Chinook Salmon SECTION 1: INTRODUCTION The Public Utility District No. 1 of Chelan County (Chelan PUD) is proposing to construct an enhanced stream along the Chelan River. This stream, located in the lower half-mile section of the Chelan River (Reach 4), would provide spawning and rearing habitat for late-run (summer/fall) chinook salmon (Oncorhynchus tshawytscha) and summer steelhead (O. mykiss). Chelan PUD proposes to provide minimum flows of 30 cubic feet per second (cfs) from December 1 through May 14 and 40 cfs from May 15 through November 30. Native vegetation planted along the riparian zone would stabilize streambanks, moderate water temperatures and improve food supply for fish. Chelan PUD reasons that the enhanced stream will provide more spawning and rearing habitat than would occur within the main-channel of the Chelan River. During high-runoff years, flows through the Chelan River can reach 6,000 cfs and scour important spawning and rearing habitat in the river. Flows in the enhanced stream would be regulated so as to reduce erosion of spawning and rearing habitat. The purpose of this report is to assess whether late-run chinook salmon would find suitable conditions and be likely to spawn within the proposed enhanced stream.1 The report first describes the distribution of late-run chinook in the state of Washington and Oregon. In this section, we identify some of the smaller streams (<50 cfs) that are used by late-run chinook for spawning. Next, the report describes the spawning habitat used by chinook. Here, we focus mostly on suitable water depths and velocities, because they are related to streamflows. We assume that suitable spawning gravels, water quality, and cover will be available and that stream temperatures will not preclude spawning. The report describes the success of artificial channels constructed for chinook spawning. Finally, the report provides a summary of stream enhancement projects that have been shown to be effective for particular target species, including late-run chinook salmon. SECTION 2: SPAWNING DISTRIBUTION OF LATE-RUN CHINOOK SALMON Late-run chinook salmon will spawn in small streams and side-channels two to three meters wide (e.g., small side-channels in the Okanogan and Methow rivers) and in the mainstem of large rivers like the Columbia and Snake rivers (Healey 1991; Miller and Hillman 1997). In this section, we identify the spawning distribution of late-run chinook salmon in the Columbia River basin, in Puget Sound, along the Washington coast, and along the Oregon Coast. We compiled a listing of all streams that late-run chinook use for spawning in Appendix A (Washington) and B (Oregon). Where available, we also included mean and maximum flows for the months of October through December. We found no flow data for most of the smaller streams. 1 This report does not consider the use of the enhanced stream by steelhead. First-Draft Study Report Lake Chelan Project No. 637 December 7, 2000 Page 1 SS/5103 Late-Run Chinook Salmon 2.1 Columbia River Basin Late-run chinook salmon in the Columbia River basin can be separated into two physiologically distinct types; the “tules” and the “upriver brights” (Myers et al. 1998). The tules spawn in the lower Columbia River basin west of the Cascade Crest, while upriver brights spawn east of the crest. Tules return to the river in mid-August and spawn within a few weeks. They spawn primarily in tributaries downstream from Bonneville Dam (Appendix A and B). They are distinguished by their dark skin coloration and advanced state of maturation at the time of freshwater entry. In contrast, brights mature more slowly (having a greater distance to travel upriver before spawning) and therefore retain their silvery oceanic coloration well into their freshwater migration. Brights spawn in the mainstem Columbia and Snake rivers and their tributaries, primarily in the Deschutes and Yakima rivers (Myers et al. 1998) (Appendix A and B). The most abundant population of brights spawns in the Hanford Reach of the Columbia River (an 84-km reach from near Richland to Priest Rapids Dam) (Swan 1989). Chapman et al. (1994) and Utter et al. (1995) considered the summer-run and fall-run (bright) chinook of the main Columbia River to consist of one evolutionarily significant unit (ESU) from the Hanford Reach through upriver areas, based on biochemical genetic traits. Thus, the late-run chinook in the upper Columbia River basin would include upriver brights and summer chinook that spawn as far upstream as the middle reaches of the Wenatchee River, Methow River, and the lower Similkameen River. A few late-run chinook also spawn in the Okanogan, Chelan, and Entiat rivers. These fish also spawn in the Columbia River between Rocky Reach Dam and Wells Dam (Giorgi 1992). Miller and Hillman (1997) observed late-run chinook spawning in the Twisp River and in small side-channels in the Methow and Okanogan rivers. Some of these channels were less than 2 m wide and some redds were in water depths of about 30 cm (1 ft). In the Entiat River, Giorgi (1992) found late-run chinook redds in water depths of 30-60 cm (1-2 ft). 2.2 Puget Sound Late-run chinook salmon spawn in most of the major streams in Puget Sound (Appendix A). For example, they spawn in the Elwha, Skokomish, Cedar, Green, Nisqually, Puyallup, White, Snohomish, Stillaguamish, Skagit, Nooksack, and Samish rivers (Cramer et al. 1999). Within many of these larger rivers they also spawn within small tributaries (Table 2-1). For example, in the Skagit, late-run chinook spawn in streams less than 2-miles long. Although we have no flow data for these streams, it is unlikely that their fall-early winter mean flows exceed 50 cfs. Chinook salmon spawn in Dogfish Creek, which is 3.5 miles long and its flows average about 8.9 cfs (Williams et al. 1975a). 2.3 Washington Coast Late-run chinook spawn in most of the major rivers along the Washington Coast (Appendix A). They spawn in the North, Willapa Bay, Elk, Satsop, Wynoochee, Chehalis, Quinault, Queets, Hoh, Calawah, Bogachiel, Sol Duc, Sooes, and Hoko rivers (Myers et al. 1998). As in the Puget Sound area, late-run chinook also spawn in small streams and tributaries. For example, in both the Chehalis and Willapa rivers, late-run chinook spawn in streams with lengths less than 4-miles long (Table 2-1). It is unlikely that these short streams have mean flows greater than 50 cfs. Lake Chelan Project No. 637 First-Draft Study Report SS/5103 Page 2 December 7, 2000 Late-Run Chinook Salmon 2.4 Oregon Coast Among the Oregon coastal rivers that support populations of chinook salmon, all support late-run chinook and less than about one-fourth support early-run (spring) chinook (Nicholas and Hankin 1988) (Appendix B). Late-run chinook spawn in the Nehalem, Miami, Kilchis, Wilson, Trask, Tillamook, Nestucca, Salmon, Siletz, Yaquina, Alsea, Siuslaw, Umpqua, Smith, Coos, Coquille, Floras, Sixes, Elk, Rogue, Hunter, Pistol, Chetco, and Winchuck rivers (Nicholas and Hankin 1988). Within these larger systems, late-run chinook spawn in smaller tributaries. One such tributary, Powell Creek in the Rogue River system, has mean flows much less than 50 cfs during the period October through December. First-Draft Study Report Lake Chelan Project No.