Draft Environmental Impact Report For The Las Flores Estates Tentative Subdivision Map Prepared for: City of El Centro 1275 W. Main Street El Centro, CA 92243 Contact: Norma Villicaña, Acting Planning Director (760) 337-4545 Prepared by: Jones & Stokes 9775 Businesspark Avenue, Suite 200 San Diego, CA 92131 Contact: Bob Stark 858/578-8964 March 2008 Jones & Stokes. 2008. Draft Environmental Impact Report for the Las Flores Estates Tentative Subdivision Map. March. (J&S 312.07.) San Diego, CA. Prepared for the City of El Centro, CA. Contents Chapter Page Summary ............................................................................................................... S-1 S.1 Project Synopsis ........................................................................ S-1 S.1.1 Project Description........................................................ S-1 S.1.2 Project Setting .............................................................. S-1 S.2 Summary of Significant Effects with Mitigation Measures ................................................................................... S-1 S.3 Project Alternatives .................................................................... S-2 S.4 Areas of Controversy ................................................................. S-2 Chapter 1 Introduction .............................................................................................. 1 1.1 Regulatory Documents .................................................................. 2 1.2 Requested Actions ......................................................................... 2 1.3 Environmental Impact Report Organization ................................... 2 Chapter 2 Project Description ............................................................................... 2-1 2.1 Project Location .......................................................................... 2-1 2.2 Project Purpose and Objectives .................................................. 2-1 2.3 Project Description ...................................................................... 2-2 2.3.1 Residential ............................................................................ 2-2 2.3.2 Park ....................................................................................... 2-2 2.3.3 Stormwater Retention Area ................................................... 2-2 2.3.4 Infrastructure ......................................................................... 2-7 2.4 Land Uses ................................................................................... 2-7 2.4.1 Low-Density Residential ....................................................... 2-8 2.5 Zoning ......................................................................................... 2-8 2.6 Required Approvals .................................................................... 2-8 Chapter 3 Environmental Setting .......................................................................... 3-1 Chapter 4 Environmental Analysis ....................................................................... 4-1 Section 4.1 Agricultural and Mineral Resources ................................................ 4.1-1 4.1.1 Existing Conditions .................................................................. 4.1-1 4.1.1.1 Agriculture in Imperial County ...................................... 4.1-1 4.1.1.2 Applicable General Plan Goals and Policies Related to Agricultural Conversion ............................... 4.1-5 4.1.1.3 Minerals in Imperial County .......................................... 4.1-5 4.1.2 Impacts and Mitigation Measures ............................................ 4.1-5 Draft Environmental Impact Report March 2008 Las Flores Estates i J&S 312.07 City of El Centro Table of Contents 4.1.2.1 Thresholds of Significance ........................................... 4.1-5 4.1.2.2 Impacts and Mitigation Measures ................................ 4.1-6 Section 4.2 Air Quality........................................................................................... 4.2-1 4.2.1 Existing Conditions .................................................................. 4.2-1 4.2.1.1 Regional Setting ........................................................... 4.2-1 4.2.1.2 Local Climatology ......................................................... 4.2-1 4.2.2 Impacts and Mitigation Measures ............................................ 4.2-7 4.2.2.1 Regulatory Setting ........................................................ 4.2-7 4.2.2.2 Thresholds of Significance ......................................... 4.2-14 4.2.2.3 Impacts and Mitigation Measures .............................. 4.2-17 Section 4.3 Biological Resources ........................................................................ 4.3-1 4.3.1 Existing Conditions .................................................................. 4.3-1 4.3.1.1 Natural Vegetation Communities and Plants ............... 4.3-1 4.3.1.2 Wildlife .......................................................................... 4.3-5 4.3.2 Impacts and Mitigation Measures ............................................ 4.3-6 4.3.2.1 Thresholds of Significance ........................................... 4.3-6 4.3.2.2 Impacts and Mitigation Measures ................................ 4.3-7 Section 4.4 Geology and Soils ............................................................................. 4.4-1 4.4.1 Existing Conditions .................................................................. 4.4-1 4.4.1.1 Regional Setting ........................................................... 4.4-2 4.4.1.2 Local Geology .............................................................. 4.4-3 4.4.2 Impacts and Mitigation Measures ............................................ 4.4-4 4.4.2.1 Thresholds of Significance ........................................... 4.4-4 4.4.2.2 Impact Analysis ............................................................ 4.4-5 Section 4.5 Hazards ............................................................................................... 4.5-1 4.5.1 Existing Conditions .................................................................. 4.5-1 4.5.1.1 Site History ................................................................... 4.5-1 4.5.1.2 Site Reconnaissance and Records Review ................. 4.5-2 4.5.1.3 Environmental Database Review ................................. 4.5-2 4.5.2 Impacts and Mitigation Measures ............................................ 4.5-3 4.5.2.1 Regulatory Setting ........................................................ 4.5-3 4.5.2.2 Thresholds of Significance ........................................... 4.5-5 4.5.2.3 Impacts and Mitigation Measures ................................ 4.5-6 Section 4.6 Hydrology and Water Quality ........................................................... 4.6-1 4.6.1 Introduction .............................................................................. 4.6-1 4.6.1.1 Surface Water Hydrology and Water Quality ............... 4.6-1 4.6.1.2 Groundwater ................................................................ 4.6-2 4.6.1.3 Flooding ....................................................................... 4.6-2 4.6.2 Impacts and Mitigation Measures ............................................ 4.6-2 4.6.2.1 Methods and Assumptions ........................................... 4.6-2 4.6.2.2 Thresholds of Significance ........................................... 4.6-3 4.6.2.3 Impacts and Mitigation Measures ................................ 4.6-3 Draft Environmental Impact Report March 2008 Las Flores Estates ii J&S 312.07 City of El Centro Table of Contents Section 4.7 Noise ................................................................................................... 4.7-1 4.7.1 Existing Conditions .................................................................. 4.7-2 4.7.1.1 Land Use and Noise-Sensitive Receivers .................... 4.7-2 4.7.1.2 Baseline Noise Monitoring ........................................... 4.7-5 4.7.1.3 Existing Traffic Noise Levels ........................................ 4.7-6 4.7.2 Impacts and Mitigation Measures ............................................ 4.7-7 4.7.2.1 Regulatory Setting ........................................................ 4.7-7 4.7.2.2 Thresholds of Significance ......................................... 4.7-10 4.7.2.3 Noise Prediction Methodology ................................... 4.7-11 4.7.2.4 Impacts and Mitigation Measures .............................. 4.7-12 Section 4.8 Public Services and Utilities ............................................................. 4.8-1 4.8.1 Existing Conditions .................................................................. 4.8-1 4.8.1.1 Water Services ............................................................. 4.8-1 4.8.1.2 Sewer Services ............................................................ 4.8-3 4.8.1.3 Solid Waste .................................................................. 4.8-5 4.8.1.4 Fire Protection/Emergency Medical Services ....................................................................... 4.8-6 4.8.1.5 Law Enforcement ......................................................... 4.8-9 4.8.1.6 Schools ...................................................................... 4.8-10 4.8.1.7 Recreation .................................................................. 4.8-11 4.8.2 Impacts and Mitigation Measures .......................................... 4.8-13 4.8.2.1 Impact Significance