Environmental Assessment for issuance of an Endangered Species Act Section 10(a)(1)(B) Permit for incidental take of Fender’s blue butterfly, Taylor’s checkerspot butterfly, Willamette daisy, Kincaid’s lupine, Bradshaw’s lomatium, Nelson’s checkermallow, and peacock larkspur in Benton County. Benton County Corvallis, Oregon U.S. Fish and Wildlife Service Portland, Oregon December 2010 Title for Proposed Action: Environmental Assessment for issuance of an Endangered Species Act Section 10(a)(1)(B) Permit for incidental take of Fender’s blue butterfly, Taylor’s checkerspot butterfly, Willamette daisy, Kincaid’s lupine, Bradshaw’s lomatium, Nelson’s checkermallow, and peacock larkspur in Benton County. Unit of Fish and Wildlife Service Proposing Action: US Fish and Wildlife Service, Portland, Oregon. Legal Mandate for Proposed Action: Endangered Species Act of 1973, as amended, Section 10(a)(1)(B), as implemented by 50 CFR 17.22 for endangered species; National Environmental Policy Act of 1969, as implemented by 40 CFR 1500, et. seq. Applicant: Benton County, Oregon. Date: December 2010. This document was prepared for U.S. Fish and Wildlife by staff at the Institute for Applied Ecology: Michelle Michaud, Habitat Conservation Planner (Primary Author) Tom Kaye, Executive Director Carolyn Menke, Conservation Biologist Rachel Schwindt, Conservation Biologist The Institute for Applied Ecology is a non-profit 501(c)(3) organization whose mission is to conserve native ecosystems through restoration, research, and education. P.O. Box 2855 Corvallis, OR 97339-2855 (541)753-3099 www.appliedeco.org Benton County Prairie Species EA Contents List of Tables ................................................................................................................................. iii List of Figures ................................................................................................................................ iii Appendices ..................................................................................................................................... iii 1 Purpose and Need for Action ....................................................................................................... 1 1.1 Introduction ..................................................................................................................... 1 1.2 Purpose ............................................................................................................................ 1 1.3 Need ................................................................................................................................ 2 1.4 Location and Scope ......................................................................................................... 3 1.5 Decisions to be made by USFWS ................................................................................... 4 2 Alternatives .................................................................................................................................. 5 2.1 Alternative 1: Proposed Action Alternative .................................................................... 5 2.1.0 Activities and Impacts of the HCP.......................................................................... 5 2.1.1 Rationale of the Proposed Alternative .................................................................... 9 2.2 No Action Alternative ................................................................................................... 10 2.3 Alternatives Considered and Rejected .......................................................................... 11 2.3.0 Benton County Coverage Only/Animal Species Only.......................................... 11 2.3.1 All Lands in Benton County/ Eight Species ......................................................... 11 2.3.2 All Lands in Benton County/Fender’s Blue Butterfly Only ................................. 12 2.3.3 Coverage of Private Development Activities on Lots Generated through Partitions in Fender’s Blue Zone ........................................................................................................... 12 2.3.4 Private Landowners Share Mitigation Costs for Impacts on their Lands ............. 13 3 Description of the Affected Environment .................................................................................. 14 3.1 Physiographic Setting ................................................................................................... 14 3.1.0 Overview ............................................................................................................... 14 3.1.1 Willamette Valley Ecoregion ................................................................................ 15 3.2 Climate .......................................................................................................................... 15 3.3 Topography/Soils .......................................................................................................... 15 3.4 Prairie Habitat Vegetation............................................................................................. 16 3.4.0 Wet Prairies ........................................................................................................... 16 3.4.1 Upland Prairies...................................................................................................... 16 3.5 Wildlife and Fish........................................................................................................... 16 3.5.0 Mammals............................................................................................................... 16 3.5.1 Amphibians ........................................................................................................... 17 3.5.2 Reptiles ................................................................................................................. 17 3.5.3 Birds ...................................................................................................................... 17 3.5.4 Invertebrates .......................................................................................................... 17 3.5.5 Fish ........................................................................................................................ 18 3.6 Listed, Proposed and Candidate Species ...................................................................... 18 3.6.0 Listed Species ....................................................................................................... 18 3.6.1 Proposed and Candidate Species .......................................................................... 22 3.7 Water Resources (Quantity and Quality) ...................................................................... 24 3.7.0 Water Quality Limited Streams ............................................................................ 25 3.7.1 Groundwater ......................................................................................................... 26 3.8 Wetlands ....................................................................................................................... 26 3.9 Air Quality .................................................................................................................... 26 i Benton County Prairie Species EA 3.10 Cultural and Historical Resources ................................................................................ 27 3.11 Land Use/Socio-Economic ........................................................................................... 27 3.12 Transportation ............................................................................................................... 29 4 Environmental Consequences .................................................................................................... 30 4.1 Proposed Action Alternative ......................................................................................... 30 4.1.0 Climate .................................................................................................................. 31 4.1.1 Topography/Soils .................................................................................................. 36 4.1.2 Prairie Habitat Vegetation..................................................................................... 38 4.1.3 Wildlife and Fish................................................................................................... 42 4.1.4 Threatened and Endangered Species .................................................................... 45 4.1.5 Critical Habitat ...................................................................................................... 58 4.1.6 Water Resources ................................................................................................... 63 4.1.7 Land Use/Socio-Economic/Environmental Justice ............................................... 67 4.1.8 Cultural and Archaeological Resources ................................................................ 68 4.1.9 Air Quality ............................................................................................................ 70 4.1.10 Transportation ....................................................................................................... 73 4.2 No-Action Alternative .................................................................................................. 75 4.2.0 Climate .................................................................................................................