Mill Creek Watershed Assessment Umpqua Basin Environmental Chemistry, Inc. Prepared by E&S Environmental Chemistry, Inc. for the Umpqua Basin Watershed Council May, 2006 Umpqua Basin Watershed Council 1758 NE Airport Road Roseburg, Oregon 97470 (541) 673-5756 www.ubwc.org Mill Creek Watershed Assessment Final Report May, 2006 Prepared by E&S Environmental Chemistry, Inc. P.O. Box 609 Corvallis, OR 97339 Kai Snyder Tim Sullivan Deian Moore Richard Raymond This document should be cited as: Snyder, K., T. Sullivan, D. Moore, and R. Raymond. 2006. Mill Creek Watershed Assessment. Prepared by E&S Environmental Chemistry, Inc. for the Umpqua Basin Watershed Council, Roseburg, OR. This project has been funded in part by the United States Environmental Protection Agency under assistance agreement CO- 000451-03 to the Oregon Department of Environmental Quality. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Mill Creek Watershed Assessment Page ii Table of Contents List of Figures................................................................................................................................ vi List of Tables ................................................................................................................................ vii List of Maps ................................................................................................................................... ix Acknowledgments........................................................................................................................... x 1. Introduction ........................................................................................................................... 1 1.1. Purpose and Development of the Watershed Assessment ............................................ 1 1.1.1. The Umpqua Basin Watershed Council .......................................................... 1 1.1.2. The Watershed Assessment and Action Plan .................................................. 1 1.1.3. Assessment Development................................................................................ 2 1.2. Watershed Description.................................................................................................. 2 1.2.1. Location, Size, and Major Features ................................................................. 2 1.2.2. Ecoregions....................................................................................................... 3 1.2.3. Topography...................................................................................................... 5 1.2.4. Geology............................................................................................................5 1.2.5. The Mill Creek Watershed Stream Network ................................................... 8 1.2.6. Climate............................................................................................................. 8 1.2.7. Vegetation........................................................................................................ 9 1.3. Land Use, Ownership, and Population ....................................................................... 10 1.3.1. Land Use and Ownership............................................................................... 10 1.3.2. Population and Demographics....................................................................... 14 1.3.2.1. Population......................................................................................... 14 1.3.2.2. General Demographic Characteristics and Housing......................... 14 1.3.2.3. Social Characteristics........................................................................ 14 2. Past Conditions...................................................................................................................... 1 2.1. Pre-Settlement: Early 1800s ......................................................................................... 1 2.1.1. Native Americans ............................................................................................ 1 2.1.2. European Visitors............................................................................................ 2 2.2. Settlement Period: Late 1840s to the 1890s................................................................. 3 2.2.1. Gold Mining.....................................................................................................4 2.2.2. Agriculture....................................................................................................... 5 2.2.3. Commercial Fishing.........................................................................................5 2.2.4. Logging............................................................................................................ 5 2.2.5. Transportation.................................................................................................. 6 2.3. Onset of the Modern Era: Early 1900s to the 1960s..................................................... 7 2.3.1. Transportation.................................................................................................. 7 2.3.2. Logging............................................................................................................ 8 2.3.3. Fisheries........................................................................................................... 9 2.3.4. Agriculture....................................................................................................... 9 2.4. Modern Era: 1970s to the Present............................................................................... 10 2.4.1. Logging.......................................................................................................... 10 2.4.2. Dam Construction.......................................................................................... 11 2.4.3. Tourism.......................................................................................................... 11 2.5. Douglas County Population Growth........................................................................... 11 2.6. Historical Changes in Vegetation ............................................................................... 12 2.7. Major Natural Disturbances........................................................................................ 12 3. Current Conditions.............................................................................................................3-1 3.1. Stream Function.........................................................................................................3-1 Mill Creek Watershed Assessment Page iii 3.1.1. Pre-Settlement Stream Channel Conditions .................................................3-1 3.1.2. Stream Morphology......................................................................................3-2 3.1.2.1. Stream Morphology and Sediment Transport Processes.................3-2 3.1.2.2. Stream Habitat Surveys...................................................................3-6 3.1.2.3. Overview of Conditions...................................................................3-8 3.1.3. Stream Connectivity...................................................................................3-13 3.1.3.1. Irrigation Ditches...........................................................................3-14 3.1.3.2. Dams..............................................................................................3-14 3.1.3.3. Culverts..........................................................................................3-14 3.1.4. Channel Modification.................................................................................3-15 3.1.4.1. Historical Channel Modification Projects .....................................3-17 3.1.4.2. Recent Channel Modification Projects ..........................................3-17 3.1.5. Stream Function Key Findings and Action Recommendations..................3-18 3.1.5.1. Stream Morphology Key Findings ................................................3-18 3.1.5.2. Stream Connectivity Key Findings................................................3-18 3.1.5.3. Channel Modification Key Findings .............................................3-18 3.1.5.4. Stream Function Action Recommendations ..................................3-18 3.2. Riparian Zones and Wetlands ..................................................................................3-20 3.2.1. Riparian Zones............................................................................................3-20 3.2.2. Wetlands.....................................................................................................3-22 3.2.2.1. Overview of Wetland Ecology....................................................3-22 3.2.2.2. Description of Current Wetlands in the Mill Creek Watershed..3-24 3.2.2.3. Restoration Opportunities in the Mill Creek Watershed.............3-24 3.2.3. Riparian Zones and Wetlands Key Findings and Action Recommendations.......................................................................................3-27 3.2.3.1. Riparian Zones Key Findings .....................................................3-27 3.2.3.2. Wetlands Key Findings...............................................................3-27 3.2.3.3. Riparian Zones and Wetlands Action Recommendations...........3-28