Upper Arroyo Seco Habitat Enhancement Plan Pasadena, Los Angeles County, California Prepared for City of Pasadena Department of Water and Power 100 North Garfield Avenue, Room N306 Pasadena, California 91109 Contact: Elisa Ventura, P.E. T: (626) 744-4465 Prepared by Psomas 225 South Lake Avenue, Suite 1000 Pasadena, California 91101 Contact: Marc Blain, Senior Project Manager/Biologist T: (626) 351-2000 F: (626) 351-2030 August 2019 Upper Arroyo Seco Habitat Enhancement Plan TABLE OF CONTENTS Section Page 1.0 Introduction ..................................................................................................................... 1 1.1 Project Location ..................................................................................................... 1 2.0 Relevant Plans, Policies, and Regulations ................................................................... 3 2.1 Hahamongna Watershed Park Master Plan .......................................................... 3 2.2 Arroyo Seco Watershed Management and Restoration Plan ................................ 3 2.3 Angeles National Forest Land Management Plan ................................................. 3 2.4 USDA-FS Weed Management Strategy ................................................................ 4 2.5 Integrated Regional Water Management Plan ...................................................... 4 2.6 One Arroyo Report ................................................................................................ 5 2.7 Arroyos & Foothills Conservancy .......................................................................... 5 2.8 Regulatory Framework .......................................................................................... 6 2.8.1 Federal ...................................................................................................... 6 2.8.2 State .......................................................................................................... 7 2.8.3 Local .......................................................................................................... 9 3.0 Physical Site Conditions .............................................................................................. 11 3.1 Topography ......................................................................................................... 11 3.2 Climate ................................................................................................................ 11 4.0 Survey Methods ............................................................................................................ 12 4.1 Invasive Vegetation Survey and Mapping ........................................................... 12 5.0 Biological Resources .................................................................................................... 13 5.1 Vegetation ........................................................................................................... 13 5.2 Wildlife ................................................................................................................. 14 6.0 Environmental Resource Protection ........................................................................... 16 6.1 Special Status Resources ................................................................................... 16 6.2 Special Status Vegetation Types......................................................................... 18 6.3 Special Status PlantS .......................................................................................... 18 6.4 Special Status Wildlife ......................................................................................... 22 6.4.1 Nesting Birds ........................................................................................... 25 6.5 Jurisdictional Resources ..................................................................................... 25 6.6 Protected Trees ................................................................................................... 25 R:\Projects\2PAS010102\Habitat Enhancement Plan\Habitat Enhancement Plan-081519.docx i Table of Contents Upper Arroyo Seco Habitat Enhancement Plan 7.0 Invasive/Non-Native Vegetation Removal ................................................................... 27 7.1 Non-Native Trees ................................................................................................ 28 7.1.1 Cut-and-Paint Stump Treatment .............................................................. 28 7.1.2 Allelopathic Litter ..................................................................................... 28 7.1.3 Retention of Coarse Woody Debris or Snags .......................................... 28 7.2 Non-Native Shrubs .............................................................................................. 28 7.3 Non-Native Annual and Perennial Herbs ............................................................ 29 7.3.1 Broadleaf weeds ...................................................................................... 29 7.3.2 Non-Native Grasses ................................................................................ 29 7.4 Ornamental Plant Species ................................................................................... 30 8.0 Native Plant and Seed Installation ............................................................................... 31 8.1 Area 1 (‘Spreading Grounds’) .............................................................................. 31 8.1.1 Container Planting ................................................................................... 31 8.1.2 Seed Mix Application ............................................................................... 32 8.1.3 Arroyo Seco Canyon Project ................................................................... 32 8.1.4 Basin Restoration .................................................................................... 32 8.2 Habitat Enhancement Demonstration Area ......................................................... 33 8.2.1 8.2.1 Restoration Goals ........................................................................... 33 8.2.2 Preliminary Ecological Assessment ......................................................... 33 8.2.3 Implementation ........................................................................................ 34 8.2.4 Native Plants and Seeds ......................................................................... 34 8.2.5 Training .................................................................................................... 34 8.2.6 Site Preparation ....................................................................................... 34 8.2.7 Site Installation ........................................................................................ 35 8.2.8 Long Term Maintenenace ........................................................................ 36 8.2.9 Long-Term Monitoring ............................................................................. 36 8.3 Area 2 (‘Riparian Corridor’) and Area 3 (‘East of Substation’) ............................. 36 8.4 Area 4 (‘Northern Mountain Slopes’) ................................................................... 36 9.0 Fencing and Interpretive Signage ............................................................................... 37 10.0 Wildlife Enhancements ................................................................................................. 37 11.0 Stakeholder Coordination ............................................................................................ 38 12.0 Implementation Approach ............................................................................................ 38 13.0 References ..................................................................................................................... 39 14.0 Glossary ......................................................................................................................... 41 R:\Projects\2PAS010102\Habitat Enhancement Plan\Habitat Enhancement Plan-081519.docx ii Table of Contents Upper Arroyo Seco Habitat Enhancement Plan TABLES Table Page 1 Slope Analysis Summary ................................................................................................ 11 2 Special Status Plant Species Known to Occur Within the Project Region ...................... 19 3 Special Status Wildlife Species Known to Occur Within the Project Region ................... 22 EXHIBITS Exhibit Follows Page 1 Habitat Enhancement Areas ............................................................................................. 1 2 Slope Analysis ................................................................................................................. 11 3 Non-Native Removals ..................................................................................................... 28 4 Sycamore Planting Area ................................................................................................. 32 5 Habitat Enhancement Areas – Upper Area 1 .................................................................. 32 APPENDICES Appendix A Specifications B Proposed Element Activity Phasing Schedule R:\Projects\2PAS010102\Habitat Enhancement Plan\Habitat Enhancement Plan-081519.docx iii Table of Contents Upper Arroyo Seco Habitat Enhancement Plan 1.0 INTRODUCTION This Upper Arroyo Seco Habitat Enhancement Plan (HEP) has been prepared to support the City of Pasadena’s goal of improving habitat functions and