D RAFT MILE SQUARE REGIONAL PARK MASTER PLAN ENVIRONMENTAL IMPACT REPORT SCH#: 2020089024 EIR NO. 633 P REPARED FOR : OC Parks 13042 Old Myford Road Irvine, CA 92602 Contact: Natalia Gaerlan P R E P A R E D B Y : ICF 49 Discovery, Suite 250 Irvine, CA 92618 Contact: Tanya Jones April 2021 ICF. 2021. Mile Square Regional Park Master Plan Environmental Impact Report. Draft. April. (ICF 359.20.) Irvine, CA. Prepared for OC Parks. Irvine, CA. Contents Page Appendices ...................................................................................................................................... vi Tables ............................................................................................................................................. vii Figures .............................................................................................................................................. x Acronyms and Abbreviations ............................................................................................................ xi Executive Summary ........................................................................................................................... ES-1 ES.1 Purpose of the EIR .............................................................................................................. ES-1 ES.2 Project Overview ................................................................................................................ ES-1 ES.3 Project Objectives ............................................................................................................... ES-1 ES.4 Project Impacts and Mitigation Measures ........................................................................... ES-2 ES.4.1 Summary of Project Impacts ................................................................................... ES-2 ES.4.2 Significant and Unavoidable Impacts .................................................................... ES-27 ES.5 Project Alternatives .......................................................................................................... ES-27 ES.6 Potential Areas of Controversy/Issues to be Resolved ....................................................... ES-30 ES.7 How to Comment on this Draft EIR ................................................................................... ES-30 Chapter 1 Introduction and Scope of Environmental Impact Report .................................................... 1-1 1.1 The Purpose of this Environmental Impact Report ................................................................ 1-1 1.2 The California Environmental Quality Act .............................................................................. 1-1 1.3 Public Agency Involvement ................................................................................................... 1-2 1.4 Scope of Analysis .................................................................................................................. 1-2 1.4.1 Document Format .................................................................................................... 1-3 1.5 Intended Use of this EIR ........................................................................................................ 1-4 1.6 Review of the EIR .................................................................................................................. 1-4 Chapter 2 Project Description .............................................................................................................. 2-1 2.1 Introduction and Overview ................................................................................................... 2-1 2.2 Project Background............................................................................................................... 2-1 2.3 Project Setting ...................................................................................................................... 2-2 2.3.1 Regional Location ..................................................................................................... 2-2 2.3.2 Local Vicinity ............................................................................................................ 2-2 2.3.3 Existing Site Characteristics ...................................................................................... 2-3 2.3.4 93-Acre Mile Square Golf Course Parcel ................................................................... 2-4 2.3.5 Surrounding Land Uses ............................................................................................. 2-4 2.3.6 Existing General Plan and Zoning .............................................................................. 2-4 2.4 Project Objectives ................................................................................................................. 2-5 Mile Square Regional Park Master Plan EIR April 2021 i ICF 359.20 OC Parks Contents 2.5 Description of the Proposed Project...................................................................................... 2-5 2.5.1 Proposed Project Improvements .............................................................................. 2-5 2.5.2 Proposed Project Phasing ......................................................................................... 2-9 2.5.3 Operations and Maintenance ................................................................................. 2-10 2.6 Required Approvals ............................................................................................................ 2-11 Chapter 3 Environmental Impact Assessment ...................................................................................... 3-1 Introduction ................................................................................................................................... 3-1 Environmental Elements Analyzed in the EIR .................................................................................. 3-1 Organization of Environmental Impact Analysis .............................................................................. 3-2 3.1 Aesthetics .......................................................................................................................... 3.1-1 3.1.1 Concepts and Terminology .................................................................................... 3.1-1 3.1.2 Environmental Setting ........................................................................................... 3.1-3 3.1.3 Regulatory Setting ................................................................................................. 3.1-8 3.1.4 Environmental Impacts........................................................................................ 3.1-10 3.2 Air Quality ......................................................................................................................... 3.2-1 3.2.1 Environmental Setting ........................................................................................... 3.2-1 3.2.2 Regulatory Setting ................................................................................................. 3.2-9 3.2.3 Environmental Impacts........................................................................................ 3.2-16 3.3 Biological Resources .......................................................................................................... 3.3-1 3.3.1 Environmental Setting ........................................................................................... 3.3-1 3.3.2 Regulatory Setting ............................................................................................... 3.3-22 3.3.3 Environmental Impacts........................................................................................ 3.3-29 3.4 Cultural Resources ............................................................................................................. 3.4-1 3.4.1 Environmental Setting ........................................................................................... 3.4-1 3.4.2 Regulatory Setting ................................................................................................. 3.4-7 3.4.3 Environmental Impacts........................................................................................ 3.4-10 3.5 Energy ............................................................................................................................... 3.5-1 3.5.1 Environmental Setting ........................................................................................... 3.5-1 3.5.2 Regulatory Setting ................................................................................................. 3.5-2 3.5.3 Environmental Impacts.......................................................................................... 3.5-4 3.5.4 References Cited ................................................................................................... 3.5-8 3.6 Geology, Soils, and Paleontological Resources ................................................................... 3.6-1 3.6.1 Environmental Setting ........................................................................................... 3.6-1 3.6.2 Regulatory Setting ................................................................................................. 3.6-4 3.6.3 Environmental Impacts.......................................................................................... 3.6-8 3.7 Greenhouse Gas Emissions ...............................................................................................