CALAPOOYA WATERSHED ANALYSIS Prepared for: Eugene District Bureau of Land Management 2890 Chad Drive Eugene, Oregon 97440-2226 Prepared by: Western Watershed Analysts 313 D Street, Suite 203 Lewiston, Idaho 83501 Maxim Technologies, Inc. P.O. Box 4699 303 Irene Street Helena, Montana 59604 June 1999 TABLE OF CONTENTS Page 1.0 WATERSHED CHARACTERIZATION ............................................1-1 1.1 Regional Setting .......................................................1-1 1.2 Human Use Characteristics ..............................................1-2 1.3 Physical Characteristics .................................................1-3 1.4 Biological Characteristics ................................................1-6 2.0 ISSUES AND KEY QUESTIONS ................................................2-1 3.0 CURRENT AND REFERENCE CONDITIONS ......................................3-1 3.1 Riparian Reserves .....................................................3-1 3.2 Erosion Processes .....................................................3-2 3.3 Hydrologic Change ....................................................3-12 3.4 Water Quality ........................................................3-17 3.5 Stream Channels .....................................................3-19 3.6 Terrestrial Resources ..................................................3-20 3.7 Riparian Resources ...................................................3-50 3.8 Aquatic Resources ....................................................3-57 REFERENCES FIGURES FIGURE 1-1 Upper Williamette River Sub-Basin FIGURE 1-2 Calapooya Watershed Analysis Unit FIGURE 1-3 Current Ownership and Land Use Allocations FIGURE 1-4 Geology Map Units FIGURE 1-5 Hydrologic Features FIGURE 1-6 Current Vegetation Seral Stages FIGURE 1-7 Special Habitat Features FIGURE 3-1 Riparian Reserves FIGURE 3-2 Landslide Inventory FIGURE 3-3 Mass Wasting Mangement Units FIGURE 3-4 Soil K Factors FIGURE 3-5 Soil Erosion Potential FIGURE 3-6 Slope Classes FIGURE 3-7 Road Types FIGURE 3-8 Soil Productivity FIGURE 3-9 ROS Potential Zones FIGURE 3-10 Source, Transport and Response Reaches FIGURE 3-11 Rosgen Classifications FIGURE 3-12 Historic Vegetation - circa 1914 FIGURE 3-13 Historic Vegetation - circa 1936 FIGURE 3-14 BLM Stand Structure FIGURE 3-15 BLM Stand Ages FIGURE 3-16 Snag Survey Locations FIGURE 3-17 Special Status Species FIGURE 3-18 Large Woody Debris Recruitment Potential FIGURE 3-19 Stream Shading Hazard Classes FIGURE 3-20 Known Fish Presence FIGURE 3-21 Potential Salmonid Species Distribution APPENDICES Appendix A Landslide Inventory Data Appendix B Hillslope Erosion Data Appendix C Road Sediment Calculations Appendix D Hydrologic Calculations Appendix E Water Quality Data Appendix F Stream Channel Summaries Appendix G Snag Survey Data Appendix H Riparian Data Summaries Appendix I Fisheries Data Summaries LIST OF TABLES TABLE 3-1 Acreages of BLM Land Use Allocations by Sub-watershed ......................3-1 TABLE 3-2 Soil Timber Productivity ................................................3-11 TABLE 3-3 Hydrologic Condition Class and Forest Canopy Density for each Vegetation Cover Type ...............................................................3-14 TABLE 3-4 Hydrologic Modeling Results for Average Storm and Current Vegetative Conditions . 3-15 TABLE 3-5 Acreages of 1914 Vegetation Classifications by Ownership Category ............ 3-20 TABLE 3-6 Acreages of 1936 Vegetation Classifications by Ownership Category ............ 3-21 TABLE 3-7 Acreages of Current Vegetation Seral Stage Classifications by Ownership Category . 3-22 TABLE 3-8 Acreages of BLM Stand Size Classes by BLM Land Use Allocation .............. 3-22 TABLE 3-9 Acreages of BLM Stand Age Classes by BLM Land Use Allocation .............. 3-23 TABLE 3-10 Terrestrial Wildlife Species Addressed in the Calapooya WAU .................. 3-24 TABLE 3-11 Snag Densities and Decay Classes for Mature/Old-growth Stands ............... 3-27 TABLE 3-12 Acreage of Current Vegetation Seral Stages within 1.2 Miles of Spotted Owl Activity Centers ............................................................. 3-33 TABLE 3-13 Acreage of BLM Stand Structure within 1.2 Miles of Spotted Owl Activity Centers ... 3-33 TABLE 3-14 Special-Status Plants Documented in the Calapooya WAU on BLM Lands ........ 3-48 TABLE 3-15 Acreage of Senstitive Plant Habitat by BLM Land Use Allocation ................ 3-49 TABLE 3-16 Coding System or Large Woody Debris ....................................3-51 TABLE 3-17 Miles of Near-Term LWD Recruitment Potential on BLM and Private Lands ....... 3-53 TABLE 3-18 Long-Term LWD Recuitment Potential on BLM and Private Lands ............... 3-54 TABLE 3-19 Minimal Stream Shade Requirements by Elevation Class ...................... 3-55 TABLE 3-20 Miles of Stream Shade Hazard Ratings on BLM and Private Lands .............. 3-56 TABLE 3-21 Known Fish Presence on BLM and Private Lands ............................3-58 TABLE 3-22 Potential Salmonid Species Distribution on BLM and Private Lands .............. 3-59 Watershed Characterization 1.0 WATERSHED CHARACTERIZATION This section provides a regional setting for the products of the region include manufacturing and Calapooya Watershed Analysis Unit (WAU) and rare metals production but occupy a relatively low describes dominant human, physical, and portion of the land use in the region. biological features and functions that characterize it. This discussion provides a basis for the Physiography, Climate, and Drainage watershed analysis, providing a context for addressing ecosystem condition and function in The Calapooya WAU lies predominantly within the the WAU. Western Cascade physiographic province as described by the Standards and Guidelines and 1.1 REGIONAL SETTING Franklin and Dyrness (1973), though some of the lands in the western portion of the WAU contain Geographic Location and Population landscapes representative of the Willamette Valley province. The Coburg Hills, a prominent The Calapooya Watershed Analysis Unit (WAU) is physiographic feature of the region, forms a located in western Oregon midway between transition between the two provinces. Western Eugene/Springfield and Albany/Corvallis within the Oregon has a maritime climate characterized by Calapooya fifth-code watershed in the eastern part wet, mild winters, cool, dry summers and a long of the Upper Willamette River Sub-basin (Figure 1­ frost-free period. Annual precipitation in the region 1). The WAU covers approximately 53 square is approximately 42.5” with average January miles (33,790 acres) within the Calapooya temperatures about 39° and July temperatures watershed, which covers about 372 square miles. averaging around 65°. By comparison, mean The Calapooya WAU is accessed by State annual precipitation within the WAU is about 55". Highway 228 between the Halsey I-5 interchange Drainages in these provinces flow to the to the west and Sweet Home to the east. The Willamette River which in turn joins the Columbia towns of Brownsville, Crawfordsville, and Holley River at Portland. (population approximately 5,689) are within or adjacent to the WAU and the entire WAU is within Vegetation and Habitat Linn County (population approximately 91,227). The Calapooya WAU itself is situated south of the Major vegetational areas of the region include the Calapooya River and extends upslope to the divide Tsuga heterophylla (western hemlock) Zone and with the Mohawk River to the south (see Figure 1­ Willamette Valley Zone described by Franklin and 2). This river is known locally as the Calapooia Dyrness (1973). Douglas-fir is typically dominant River though referenced by the BLM as the in the western hemlock Zone as a sub-climax Calapooya River and should not be mistaken for a species at various seral stages reflective of the drainage of the same name to the south. disturbance in the post-settlement period. Grasslands, Oregon white oak woodlands, and Ownership and Land Use coniferous stands of Douglas-fir represent the successional pattern in the Willamette Valley Zone Forest and agricultural production represent the though much of this zone is in agricultural predominant land uses in the region. The Bureau production. These vegetational areas are entirely of Land Management and Forest Service are the within the range of the Northern Spotted Owl. Big major federal land administrators in the region. game including Roosevelt elk and black-tailed The Calapooya WAU is within the McKenzie deer are also found throughout the region. Finally, Resource Area of BLM’s Eugene District. The extensive riparian areas and aquatic habitat Willamette National Forest is located east and conditions support anadromous and resident upstream of the WAU. Several large private salmonid fisheries within the WAU and the industrial forest land owners are also represented. Calapooya watershed. Agriculture operations are primarily restricted to the valley bottoms and include grass seed, dairy, 1.2 HUMAN USE CHARACTERISTICS and livestock production. Other significant Calapooya Watershed Analysis 1 - 1 Watershed Characterization Ownership Land Use Land ownership within the Calapooya WAU is Prior to the performance of this watershed presented in Figure 1-3. Small private landowners analysis, three land use allocations have been represent the single largest ownership category in designated for BLM lands in the Calapooya WAU the WAU (approximately 13,116 acres). Close to pursuant to the Eugene District’s Record of 700 small private landowner parcels exist