Williamson County Regional Habitat Conservation Plan Final
Total Page:16
File Type:pdf, Size:1020Kb
Final Williamson County Regional Habitat Conservation Plan FINAL WILLIAMSON COUNTY REGIONAL HABITAT CONSERVATION PLAN Prepared for Williamson County Conservation Foundation 350 Discovery Boulevard, Suite 207 Cedar Park, Texas 78613 Prepared by SWCA Environmental Consultants 4407 Monterey Oaks Boulevard Building 1, Suite 110 Austin, Texas 78749 www.swca.com Smith, Robertson, Elliott, Glen, Klein & Bell, L.L.P. 221 West 6th Street, Suite 1100 Austin, Texas 78701 Prime Strategies, Inc. 1508 South Lamar Boulevard Austin, Texas 78704 Capital Market Research, Inc. 605 Brazos Street #300 Austin, Texas 78701 Texas Perspectives, Inc. 1310 South 1st Street Suite 105 Austin, Texas 78704 SWCA Project Number 10622-139-AUS August 15, 2008 [THIS PAGE INTENTIONALLY BLANK] Table of Contents TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................... vii CHAPTER 1 — BACKGROUND, PURPOSE, AND NEED ....................................................1-1 1.1 Background ..................................................................................................................1-1 1.1.1 Introduction..........................................................................................................1-1 1.1.2 Species Conservation Efforts Conducted by Williamson County .......................1-4 1.1.3 The Williamson County Regional Habitat Conservation Plan ............................1-6 1.1.4 The Concept and Benefits of a Regional Habitat Conservation Plan ..................1-6 1.2 Texas State Law Relevant to Regional Habitat Conservation Plans............................1-8 1.3 Purpose and Need for Action .......................................................................................1-9 1.4 Termination Statement ...............................................................................................1-10 CHAPTER 2 — ALTERNATIVES CONSIDERED BUT NOT SELECTED...........................2-1 2.1 Introduction ..................................................................................................................2-1 2.2 Alternative 1: No Action .............................................................................................2-1 2.3 Alternative 2: Modified (Reduced Take and Mitigation) Williamson County RHCP ...........................................................................................................................2-2 2.4 Alternative 3: Williamson County Land Use Zoning-Based RHCP...........................2-6 2.5 Alternative 4: Williamson County RHCP with Upfront Purchase of All Preserves...2-7 CHAPTER 3 – PERMITTED AND ADDITIONAL SPECIES..................................................3-1 3.1 Introduction ..................................................................................................................3-1 3.2 Covered Species ...........................................................................................................3-3 3.2.1 Karst Invertebrates...............................................................................................3-3 3.2.1.1.....Bone Cave Harvestman (Texella reyesi)..........................................................3-5 3.2.1.2.....Coffin Cave Mold Beetle (Batrisodes texanus)...............................................3-7 3.2.1.3.....Primary Threats to the Karst Invertebrates ......................................................3-7 3.2.1.4.....Travis/Williamson Counties Karst Invertebrate Recovery Plan......................3-9 3.2.1.5.....Distribution and Status of the Karst Invertebrates in Williamson County ......3-9 3.2.2 Migratory Songbirds ..........................................................................................3-13 3.2.2.1.....Golden-cheeked Warbler (Dendroica chrysoparia) ......................................3-13 3.2.2.2.....Black-capped Vireo (Vireo atricapilla).........................................................3-24 3.3 Additional Species......................................................................................................3-30 3.3.1 Karst Invertebrates.............................................................................................3-30 3.3.1.1.....Tooth Cave Ground Beetle (Rhadine persephone)........................................3-33 3.3.2 Salamanders .......................................................................................................3-33 3.3.2.1.....Georgetown Salamander (Eurycea naufragia) ..............................................3-33 3.3.2.2.....Jollyville Plateau Salamander (Eurycea tonkawae).......................................3-35 3.3.2.3.....Salado Springs Salamander (Eurycea chisholmensis) ...................................3-37 3.3.2.4.....Buttercup Creek Salamander (Eurycea n.sp.)................................................3-37 Final Williamson County i Regional Habitat Conservation Plan Table of Contents Table of Contents, continued CHAPTER 4 – COVERED ACTIONS .......................................................................................4-1 4.1 Authorized Actions ......................................................................................................4-1 4.2 Impacts of Covered Actions on Karst Invertebrate Species.........................................4-2 4.2.1 Estimating Take of Karst Invertebrates ...............................................................4-2 4.2.2 Impacts of Covered Actions on Karst Habitat .....................................................4-3 4.2.3 Impacts of Covered Actions on Occupied Karst Habitat.....................................4-7 4.2.3.1.....Levels of Impact on Occupied Karst Habitat...................................................4-7 4.2.3.2.....Estimated Number of Affected Caves ...........................................................4-10 4.3 Impacts of Covered Actions on Golden-cheeked Warbler.........................................4-13 4.3.1 Types of Impacts That May Result from Covered Actions ...............................4-13 4.3.2 Estimated Acres of Take of Golden-cheeked Warbler Habitat .........................4-15 4.4 Impacts of Covered Actions on Black-capped Vireo.................................................4-18 4.5 Georgetown Salamander ............................................................................................4-19 4.6 Cumulative Impacts....................................................................................................4-20 4.6.1 Cumulative Impacts on Karst Species ...............................................................4-20 4.6.2 Cumulative Impacts on Golden-cheeked Warbler.............................................4-21 4.6.3 Cumulative Impacts on Black-capped Vireo .....................................................4-22 CHAPTER 5 – AVOIDANCE, MINIMIZATION, AND MITIGATION MEASURES............5-1 5.1 Goals and Objectives of the Williamson County RHCP..............................................5-1 5.1.1 Biological Goals and Objectives of the RHCP....................................................5-1 5.1.1.1.....Biological Goals...............................................................................................5-2 5.1.1.2.....Biological Objectives.......................................................................................5-2 5.1.1.3.....Conservation Measures for Attaining Biological Objectives ..........................5-3 5.2 RHCP Program Administration ...................................................................................5-5 5.3 Karst Invertebrates (Covered Species).........................................................................5-7 5.3.1 Conservation Plan Components...........................................................................5-7 5.3.1.1.....Land Acquisition and Management for Mitigation .........................................5-7 5.3.1.2.....Land Acquisition and Management for Recovery Enhancement ..................5-10 5.4 Golden-cheeked Warbler (Covered Species) .............................................................5-11 5.4.1 Conservation Plan Components.........................................................................5-11 5.4.1.1.....Identifying, Avoiding, and Minimizing Impact to Warbler Habitat..............5-11 5.4.1.2.....Minimizing Disturbance during the Nesting Season .....................................5-12 5.4.1.3.....Mitigating Impacts to Warbler Habitat through Conservation Bank Credits 5-12 5.4.1.4.....Purchasing and Preserving Warbler Habitat within Williamson County ......5-13 5.5 Black-capped Vireo (Covered Species) .....................................................................5-14 5.5.1 Conservation Plan Components.........................................................................5-14 5.5.1.1.....Preserving Black-capped Vireo Habitat through Avoidance.........................5-14 5.5.1.2.....Minimizing Disturbance during the Nesting Season .....................................5-14 5.5.1.3.....Vireo Habitat Management and Restoration Program in Williamson County............................................................................................................5-14 5.6 Additional Species......................................................................................................5-15 5.6.1 Georgetown Salamander....................................................................................5-16 5.6.1.1.....Georgetown Salamander Research and Monitoring