CHETCO RIVER WATERSHED ASSESSMENT Prepared for The Chetco River Watershed Council Prepared by Mike Maguire South Coast Watershed Council June 2001 South Coast Watershed Council PO Box 666 Gold Beach, Oregon 97444 (541) 247-2755 TABLE OF CONTENTS ABSTRACT AND ACKNOWLEDGEMENTS……………………………………...…i INTRODUCTION AND PURPOSE………………………………………………..…..ii I WATERSHED CHARACTERIZATION………………………….…………..1 INTRODUCTION AND SUBWATERSHEDS……………………..………………………..…1-2 LAND OWNERSHIP AND USE………………………………………………………………..2-4 II WATERSHED ISSUES………………………………………………………….5 BACKGROUND AND INTRODUCTION ………………………………………………………5 RESULTS………………………………………………………………………………………..5-6 III HISTORICAL CONDITIONS………………………………………………….7 INTRODUCTION…………………………………………………………………………………7 SUMMARY…………………………………………………………………………….………7-12 IV ECOREGIONS………………………………………………………………....13 BACKGROUND AND INTRODUCTION……………………………………………..…....13-14 DESCRIPTION OF ECOREGIONS………………………………………………………….14-21 V CHANNEL HABITAT TYPES……………………………………………..…23 BACKGROUND……………………………………………………………………………..…..23 INTRODUCTION AND METHODOLOGY………….……………………………………..23-24 CHANNEL SENSITIVITY / RESPONSIVENESS…………………………………………..24-25 DESCRIPTION OF CHANNEL HABITAT TYPES………………………...………………25-34 RESULTS AND KEY FINDINGS.…………………………………………………….…….34-36 VI FISH & FISH HABITAT…..…………………………………………………..38 BACKGROUND……………………………………………………………………………...38-42 INTRODUCTION…………………………………………………………………………….42-47 KEY FINDINGS……………………………………………………………………………...48-49 VII WATER QUALITY…………………………………………………………….50 BACKGROUND……………………………………………………………………………...50-53 INTRODUCTION…………………………………………………………………………….53-56 METHODOLOGY……………………………………..…………………………………….…..56 RESULTS……………………………………………………………………………………..56-59 KEY FINDINGS………………………………………………..…………………………….......60 VIII SEDIMENT SOURCES…………………………………..……………………61 BACKGROUND……………………………………………………………….……………..61-62 INTRODUCTION………………………………………………………………...…………..62-63 METHODOLOGY…………………………………………………………………...……….63-64 RESULTS AND KEY FINDINGS ……………………………………………………………...64 OTHER……………………………………………………………………………………...……65 IX RIPARIAN………………………………………………………………………66 BACKGROUND……………………………………………………………………………...66-67 INTRODUCTION…………………………………………………………………….………67-68 METHODOLOGY……………………………………………………………...…………….68-69 RESULTS………………………………………………………………………….……………..70 KEY FINDINGS………………………………………………………..………………………...71 X WETLANDS………………………………………………………….…………73 BACKGROUND………………………………………………………………………….…..73-74 INTRODUCTION………………………………………………………………………...…..74-76 METHODOLOGY………………………………………………………………………….…....77 RESULTS, KEY FINDINGS AND DISCUSSION.………………………………………….….78 XI HYDROLOGY…………………………………………………….……………79 BACKGROUND…………………………………………………………………..……………..80 INTRODUCTION………………………………………………………………………….…81-84 FORESTRY IMPACTS ON HYDROLOGY…………………………………………......….84-88 METHODOLOGY AND RESULTS……………………………………………...…85-86 KEY FINDINGS.AND DISCUSSION……………………..………………………..86-88 AGRICULTURE AND RANGELAND IMPACTS ON HYDROLOGY……………………88-92 METHODOLOGY………………………………………………………………..….90-91 RESULTS AND KEY FINDINGS……..……………………………..……………..91-92 FOREST AND RURAL ROAD IMPACTS ON HYDROLOGY……………………………92-94 INTRODUCTION……………………………………………………………...…..…....93 METHODOLOGY AND RESULTS…………….…………….……………………..…93 KEY FINDINGS………………………………………………………………………...94 URBAN IMPACTS ON HYDROLOGY………………………………………………...………94 METHODOLOGY……………………………………………………………..………..94 RESULTS AND KEY FINDINGS……………………………………………..………..95 XII WATER USE……………………………………………………………………97 BACKGROUND…………………………………………………………………….………97-100 INTRODUCTION…………………………………………………………………………...….100 METHODOLOGY………………………………………………………………………....100-103 RESULTS KEY FINDINGS….…………………..………………………………………….…103 XIII WATERSHED SYNTHESIS…………………………………………………104 XIV APPENDIX…………………………………………………………………….106 ABSTRACT The Chetco River Watershed Assessment was prepared for the Chetco River Watershed Council whose members are dedicated to sustaining the health of their watershed. This document contains detailed information about the Chetco River watershed and follows guidelines described in the Governor’s Watershed Enhancement Board’s 1999 Draft Oregon Watershed Assessment Manual. Funding was provided by the Oregon Watershed Enhancement Board, Oregon Department of Environmental Quality, United States Bureau of Land Management, Oregon Department of Agriculture, Curry County Soil and Water Conservation District and Oregon State University Extension Service. ACKNOWLEDGEMENTS The completion of the Chetco River Watershed Assessment was accomplished through the combined effort of private citizens, watershed council members, contracted technical specialists, and local state and federal government agencies. The South Coast Watershed Council would like to thank the following people who generously provided time and energy to improve the quality of this assessment. Additional people helped whose names are not included below. We also acknowledge them. CONTRIBUTORS Cindy Meyers Riparian, Sediment, and Fish Matt Swanson Riparian and Wetland Chris Massingill Watershed Synthesis and Fish Joe Wierzba and Harry Hoogesteger Fish Hyatt Barnes Computer Support Lucy LaBonte, Carol Barnes History and Gerry Livingston Mike Mathews Riparian REVIEWERS Harry Hoogesteger South Coast Watershed Council Cindy Meyers South Coast Watershed Council Matt Swanson South Coast Watershed Council Chris Massingill South Coast Watershed Council Connie Risley United States Forest Service Frank Burris Oregon State University Extension Service Dale Stewart United States Bureau of Land Management Todd Confer Oregon Department of Fish and Wildlife Kathy Wiggins Oregon Department of Forestry Bruce Follansbee Lower Rogue Watershed Council Russ Stauff Oregon Department of Fish and Wildlife Lloyd Van Gordon Oregon Department of Water Resources Chetco River Watershed Assessment i INTRODUCTION & PURPOSE The Chetco River Watershed Assessment contains technical information about past and present conditions in the watershed. This document updates and expands on information presented in the South Coast Watershed Action Plan (1995). This assessment is a resource to promote better understanding of the Chetco River and its drainage area. The assessment was conducted in response to a need for more detailed information on salmonid fish and their habitat as well as water quality within the watershed. Particular emphasis was placed on private lands within the basin. The Chetco River Watershed Assessment is based on current information and should be periodically updated, as new information becomes available. The assessment methodology followed guidance provided by the Governor’s Watershed Enhancement Board’s 1999 Draft Oregon Watershed Assessment Manual. In some instances, diversions were made from this manual based on discussions with technical specialists and/or limitations pertaining to the time and scope of the project. The assessment examined historical conditions, ecoregions, channel habitat types, salmonid fish and their habitat, water quality, sediment sources, riparian conditions, wetland conditions, hydrology and water use. Among the components addressed in the Oregon Watershed Assessment Manual that were not included in this assessment was an assessment of channel modifications. The purpose of this assessment was to compile, summarize and synthesize existing data and information pertaining to Chetco River’s watershed conditions. Near completion of this document an interdisciplinary team, comprised of twelve technical specialists, reviewed the individual components of the assessment. The interdisciplinary team later met to discuss key findings, issues and/or concerns related to each of the assessment components. This information was then synthesized to provide a foundation for the prioritization of projects outlined in the Chetco River Watershed Action Plan (August, 2001). The action plan is a complementary document that addresses site specific and watershed wide recommendations for achieving restoration, enhancement and protection goals. Chetco River Watershed Assessment ii I WATERSHED CHARACTERIZATION A INTRODUCTION The Chetco River, located almost entirely within Curry County, drains approximately 352 square miles or 225,000 acres. The Chetco is the largest coastal watershed (excluding the Rogue River) in Oregon south of the Coquille. The Chetco mainstem is about 56 miles long with its headwaters and the first 28 miles of the mainstem located within the Kalmiopsis Wilderness. Flowing in a westerly direction the Chetco empties into the Pacific Ocean at Chetco Cove located about 6 miles north of the California line between the towns of Brookings and Harbor. Elevations in the watershed range from sea level to approximately 5,098 feet on Pearsoll Peak. Major tributaries include Box Canyon Creek, Tincup Creek, Boulder Creek, Mislatnah Creek, Quail Prairie Creek, Eagle Creek, South Fork, Emily Creek, North Fork and Jack (s) Creek. The upper portion of the basin is characterized by steeply sloped forested areas with narrow valleys and tributary streams that have moderately steep to very steep gradient. The lowest 11 miles of the river is bordered by private land. Rural residential development, forestry, and urban areas are the dominant land uses in this lower portion of the basin. The Chetco estuary, estimated at 1.7 miles in length has been substantially altered from its natural state. B SUBWATERSHEDS The Chetco River watershed was divided into 17 “subwatersheds” for the purpose of this assessment. These subwatersheds generally follow hydrologic boundaries. However, some units include a series of small watersheds that do not drain into a common stream or