United States Department of the Interior Bureau of Land Management June 2016 Environmental Assessment DOI-BLM-CO-S050-2014-0037 EA North Delta Grazing Permit Renewals Location: BLM Public Lands North of Delta, Colorado U.S. Department of the Interior Bureau of Land Management Uncompahgre Field Office 2465 South Townsend Avenue Montrose, CO 81401 Phone: (970) 240-5300 TABLE OF CONTENTS TABLE OF CONTENTS ........................................................................................................................................ 2 BACKGROUND/INTRODUCTION ..................................................................................................................... 6 PURPOSE AND NEED FOR THE ACTION ...................................................................................................... 13 PLAN CONFORMANCE REVIEW .................................................................................................................... 13 SCOPING, (INTERNAL AND EXTERNAL) AND ISSUES: ............................................................................ 17 DESCRIPTION OF PROPOSED ACTION AND ALTERNATIVES ................................................................ 20 Proposed Action (Current Livestock Grazing Management) (also the No Action Alternative) ............. 20 Modified Grazing Alternative (BLM’s Preferred Alternative) .................................................................. 21 No Grazing Alternative .................................................................................................................................. 32 ALTERNATIVES CONSIDERED BUT ELIMINATED FROM DETAILED ANALYSIS ...................... 40 Reduced-Grazing Strategy for LHA Findings - Considered but Not Carried Forward .......................... 40 AFFECTED ENVIRONMENT and ENVIRONMENTAL CONSEQUENCES ................................................. 41 AREAS OF CRITICAL ENVIRONMENTAL CONCERN (ACEC) ........................................................ 46 WILD AND SCENIC RIVERS ..................................................................................................................... 48 LANDS WITH WILDERNESS CHARACTERISTICS ............................................................................. 49 CULTURAL RESOURCES ........................................................................................................................... 51 NATIVE AMERICAN RELIGIOUS CONCERNS .................................................................................... 53 SOILS (includes a finding on Standard 1) .................................................................................................... 54 VEGETATION (includes a finding on Standard 3) .................................................................................... 59 INVASIVE, NON-NATIVE SPECIES (includes a finding on Standard 3) .............................................. 86 TERRESTRIAL WILDLIFE; including Migratory and Special Status Birds, Special Status Terrestrial Wildlife ............................................................................................................................................................. 89 THREATENED, ENDANGERED, AND SENSITIVE SPECIES PLANTS (includes a finding on Standard 4) .................................................................................................................................................... 122 WILDLIFE, AQUATIC INCLUDING THREATENED, ENDANGERED, AND SENSITIVE SPECIEs (includes a finding on Standard 3 & 4) ....................................................................................................... 135 WETLANDS & RIPARIAN ZONES (includes a finding on Standard 2) ............................................... 139 WATER -- SURFACE (includes a finding on Standard 5) ....................................................................... 143 SOCIO-ECONOMICS ................................................................................................................................. 149 RANGE MANAGEMENT ........................................................................................................................... 152 FIRE ............................................................................................................................................................... 162 CUMULATIVE IMPACTS ............................................................................................................................. 163 ACEC ............................................................................................................................................................. 170 Lands with Wilderness Characteristics ...................................................................................................... 170 Wild and Scenic Rivers ................................................................................................................................. 170 Soils................................................................................................................................................................. 172 Vegetation ...................................................................................................................................................... 172 Invasive, non-native species ......................................................................................................................... 173 Terrestrial Wildlife, including Migratory and Special Status Birds, Special Status Terrestrial Wildlife ......................................................................................................................................................................... 174 Threatened, Endangered, and sensitive species Plants.............................................................................. 175 Wetlands and riparian zones ....................................................................................................................... 176 Water-Surface ............................................................................................................................................... 176 Socio-Economics ............................................................................................................................................ 177 Range Management ...................................................................................................................................... 178 Consultation and Coordination ........................................................................................................................... 179 INTERDISCIPLINARY REVIEW:................................................................................................................ 181 Appendix A: Drought Monitoring Plan ............................................................................................................. 183 2 Appendix B: Bighorn /Domestic Sheep Risk of Association Modeling............................................................ 190 Disease Summary .......................................................................................................................................... 190 Probability of Interaction Model (PoIM) ................................................................................................... 191 Risk of Contact Model (RoC)....................................................................................................................... 197 Additional Discussion ................................................................................................................................... 202 Tables ............................................................................................................................................................. 206 Figures ............................................................................................................................................................ 235 Appendix B Literature ................................................................................................................................. 239 Appendix C ......................................................................................................................................................... 243 REFERENCES ................................................................................................................................................... 284 TABLE OF TABLES Table 1 North Delta Allotments .............................................................................................................................. 7 Table 2. Land Health Assessment Summary by Allotment .................................................................................... 9 Table 3 Land Health Acreage by Allotment for Standard 3 Healthy Vegetation Communities ......................... 12 Table 4 Proposed Action (Current Livestock Grazing Management) Grazing Allotments and Authorization .... 20 Table 5 Summary of 10 Year Actual Use ............................................................................................................. 23 Table 6. Modified Grazing Alternative AUM Adjustments ................................................................................. 25 Table 7 Drought Trigger Points ............................................................................................................................ 30 Table 8 Summary of Alternatives ........................................................................................................................