Lake Powell Pipeline Project Final Study Report 12 Special Status Plant Species and Noxious Weeds April 2016 Table of Contents EXECUTIVE SUMMARY .................................................................................................................. ES-1 CHAPTER 1 INTRODUCTION ............................................................................................................ 1-1 1.1 Introduction ................................................................................................................................... 1-1 1.2 Summary Description of LPP Project Alignment Alternatives ..................................................... 1-1 1.2.1 South Alternative ................................................................................................................... 1-1 1.2.2 Existing Highway Alternative ............................................................................................... 1-8 1.2.3 Southeast Corner Alternative ................................................................................................. 1-8 1.2.4 Transmission Line Alignments ............................................................................................ 1-10 1.2.5 Natural Gas Pipeline and Generators Alternative ................................................................ 1-13 1.3 Summary Description of No Lake Powell Water Alternative ..................................................... 1-18 1.3.1 WCWCD No Lake Powell Water Alternative ..................................................................... 1-19 1.3.2 KCWCD No Lake Powell Water Alternative ...................................................................... 1-23 1.4 Summary Description of the No Action Alternative ................................................................... 1-23 1.4.1 WCWCD No Action Alternative ......................................................................................... 1-23 1.4.2 KCWCD No Action Alternative .......................................................................................... 1-23 1.5 Identified Issues ........................................................................................................................... 1-24 1.6 Impact Topics .............................................................................................................................. 1-24 CHAPTER 2 STUDY AREA .................................................................................................................. 2-1 2.1 Project Overview ........................................................................................................................... 2-1 2.2 Project Alignment .......................................................................................................................... 2-1 2.3 Land Ownership ............................................................................................................................ 2-1 2.4 Ecological Setting .......................................................................................................................... 2-2 2.4.1 Colorado Plateau ................................................................................................................... 2-2 2.4.2 Mojave Desert ....................................................................................................................... 2-2 2.5 Climate .......................................................................................................................................... 2-5 2.5.1 Climatic Effects on the Field Survey ..................................................................................... 2-5 2.6 Survey Area ................................................................................................................................... 2-9 CHAPTER 3 METHODOLOGY ........................................................................................................... 3-1 3.1 Pre-survey Preparations, Field Equipment, and Materials ............................................................ 3-1 3.2 Survey .......................................................................................................................................... 3-18 3.3 50-meter Transects ................................................................................................................. 3-23 3.4 Analysis ....................................................................................................................................... 3-24 Lake Powell Pipeline i 4/30/2016 Final Special Status Plant Species/Noxious Weeds Study Report Utah Board of Water Resources Table of Contents CHAPTER 4 SPECIAL STATUS SPECIES ......................................................................................... 4-1 4.1 Introduction ................................................................................................................................... 4-1 4.2 Results of Special Status Species Survey ...................................................................................... 4-3 4.3 Species Accounts ........................................................................................................................... 4-4 4.3.1 Acer glabrum (Rocky Mountain maple) ................................................................................ 4-4 4.3.2 Acer grandidentatum (Bigtooth maple) ................................................................................. 4-4 4.3.3 Aralia racemosa (American spikenard) ................................................................................. 4-5 4.3.4 Arctomecon humilis (Dwarf bear-poppy) ............................................................................. 4-6 4.3.5 Asclepias welshii (Welsh’s milkweed) .................................................................................. 4-7 4.3.6 Astragalus ampullarioides (Shivwits milkvetch) ................................................................... 4-8 4.3.7 Astragalus ampullarius (Gumbo milkvetch) .......................................................................... 4-8 4.3.8 Astragalus holmgreniorum (Paradox milkvetch) ................................................................... 4-9 4.3.9 Astragalus striatiflorus (Escarpment milkvetch) ................................................................. 4-10 4.3.10 Camissonia bairdii (Baird camissonia) .............................................................................. 4-11 4.3.11 Camissonia gouldii (Diamond Valley suncup) .................................................................. 4-11 4.3.12 Ceanothus greggii var. vestitus (Mohave ceanothus) ........................................................ 4-12 4.3.13 Cladium californicum (California sawgrass) ..................................................................... 4-12 4.3.14 Cornus sericea (Red-osier dogwood)................................................................................. 4-13 4.3.15 Cryptantha semiglabra (Smooth catseye) .......................................................................... 4-14 4.3.16 Cycladenia humilis var. jonesii (Jones cycladenia) ........................................................... 4-23 4.3.17 Cystopteris utahensis (Utah brittle-fern) ........................................................................... 4-23 4.3.18 Echinocactus polycephalus var. xeranthemoides (Kanab barrel cactus) ........................... 4-24 4.3.19 Enceliopsis argophylla (Silverleaf sunray) ........................................................................ 4-30 4.3.20 Epilobium nevadense (Nevada willowherb) ...................................................................... 4-30 4.3.21 Euphorbia nephradenia (Utah spurge) ............................................................................... 4-31 4.3.22 Gilia latifolia var. imperialis (Cataract gilia) ..................................................................... 4-31 4.3.23 Habenaria zothecina (Alcove bog orchid) ......................................................................... 4-32 4.3.24 Imperata brevifolia (Satintail grass) .................................................................................. 4-32 4.3.25 Jamesia americana var. zionis (Zion jamesia) ................................................................... 4-33 4.3.26 Lepidium montanum var. claronense (Claron pepperplant) .............................................. 4-34 4.3.27 Lupinus caudatus var. cutleri (Cutler lupine) .................................................................... 4-34 4.3.28 Mentzelia memorabalis (September 11 stickleaf) ............................................................. 4-41 4.3.29 Oenothera murdockii (Chinle evening primrose) .............................................................. 4-41 4.3.30 Ostrya knowltonii (Western hophornbeam) ...................................................................... 4-42 4.3.31 Pediocactus peeblesianus var. fickeiseniae (Fickeisen pincushion cactus) ....................... 4-42 Lake Powell Pipeline ii 4/30/2016 Final Special Status Plant Species/Noxious Weeds Study Report Utah Board of Water Resources Table of Contents 4.3.32 Pediocactus sileri (Siler’s pincushion cactus) .................................................................... 4-43 4.3.33 Pediomelum aromaticum var. barnebyi (Indian breadroot) ............................................... 4-56 4.3.34 Pediomelum epipsilum (Kane breadroot) .........................................................................