WatershedWatershed ManagementManagement ImprovementsImprovements inin thethe ChinoChino BasinBasin PREPARED FOR: Chino Basin Water Conservation District 4594 San Bernardino Street Montclair, California 91763 Associates 13620 Metropolis Avenue, Suite 110 Fort Myers, Florida 33912 O 239.204.5300 F 866.398.2426 JUNE 2018 FINAL REPORT www.waterscienceassociates.com Watershed Management Improvements in the Chino Basin PREPARED FOR: Chino Basin Water Conservation District 4594 San Bernardino Street Montclair, California 91763 Roger Copp Senior Water Resource Modeler JUNE 2018 FINAL REPORT W. Kirk Martin, P.G. 79 Principal Hydrogeologist Associates TABLE OF CONTENTS SECTION A INTRODUCTION AND BACKGROUND ............................................................................. 1 SECTION B ASSESSMENT OF EXISTING WATERSHED MANAGEMENT ....................................... 3 SECTION C PLANNED FUTURE IMPROVEMENTS ............................................................................. 6 SECTION D CONFLUENCE REGIONAL WATER RESOURCE PROJECT CONCEPTUAL DESIGN .................................................................................................................. 7 SECTION E WATER QUALITY BENEFITS OF THE CONFLUENCE REGIONAL WATER RESOURCE PROJECT .................................................................................................... 12 SECTION F ADDITIONAL PROJECTS TO CAPTURE AND RECHARGE STORMWATER............... 13 SECTION G RECOMMENDATIONS ..................................................................................................... 14 SECTION H REFERENCES .................................................................................................................. 16 FIGURES Figure 1 Map of the Chino Basin ....................................................................................................... 2 Figure 2 Recharge Basins in the Chino Basin .................................................................................. 3 Figure 3 Estimated Streambed Iniltration in the Chino Basin and Increased Recharge Resulting from Recharge Master Plan ................................................................................................ 4 Figure 4 Measured Water Levels in the Brooks Recharge Basin ..................................................... 8 Figure 5 Measured Water Leves in Montclair Recharge Basins 1, 2, and 3 ..................................... 9 Figure 6 Estimated Capture Volumes for the Proposed Confluence Project and Total Annual Flow for Chino Creek at Schaeffer Ave. ...................................................... 10 TABLES Table 1 Summary of Flows Captures by the Confluence Project .................................................... 7 Table 2 Water Quality Benefits Associated with the Confluence Project ...................................... 12 APPENDICES Appendix A Water Quality Analysis for the Confluence Water Storage Project Table A-1 Average Concentrations of Water Quality Constituents for Chino Creek at Central Ave. ...................................................... A-2 Figure A-1 Measured Fecal Coliform Levels vs Flow for Chino Creek at Central Ave. ...................................................................... A-2 Figure A-2 Measured Electrical Conductivity vs Flow for Chino Creek at Central Ave. ...................................................................... A-2 Figure A-3 Measured Total Suspended Solids vs Flow for Chino Creek at Central Ave. ...................................................................... A-3 Figure A-4 Measured Nitrate Nitrogen for Chino Creek at Pine Ave. ............... A-3 Appendix B Proposed Water Quality Monitoring Program Table B-1 Information on Sampling Locations ................................................ B-1 Table B-2 Proposed Water Quality Constituents for Analysis ......................... B-1 Figure B-1 Map of Sampling Stations ............................................................... B-2 SECTION A INTRODUCTION AND BACKGROUND Water Science Associates conducted a planning level assessment of existing and proposed watershed management efforts in the Chino Basin with the objective of recommending additional projects that will have the potential to increase groundwater recharge, reduce salt content in the Chino Basin aquifers, and improve water quality. This effort was conducted for the Chino Basin Water Conservation District (CBWCD). The Chino Basin is located primarily in San Bernardino County in southern California east of Los Angeles County, north of the Santa Ana River, and includes the cities of Upland, Montclair, portions of Rancho Cucamonga, Ontario, Eastvale, Chino, Chino Hills, Norco, Pomona, and others. The sphere of influence for CBWCD includes portions of Upland north of I-210, portions of Rancho Cucamonga north of I-210 and east of I-15, and Fontana. The Chino Basin is bounded by the Cucamonga Basin and the San Gabriel Mountains to the north, the Rialto-Colton Basin to the northeast, the chain of the Jurupa, Pedley, and La Sierra Hills to the southeast, the Temescal Basin to the south, the Chino and Puente Hills to the southwest, and the San Jose Hills and Pomona and Claremont Basins to the northwest as shown in Figure 1. The Chino Basin has experienced years of land use changes that have reduced groundwater recharge, extracted groundwater for agricultural and public water supply, and introduced contaminants such as total dissolved solids (TDS) and nitrate-nitrogen in the aquifer (Wildermuth Environmental and Black & Veatch, 2001; Wildermuth, 2015). These activities have reduced groundwater levels in the basin and contributed to land subsidence in portions of the basin by more than seven feet along with ground fissuring (Wildermuth Environmental, Inc., 2017a). In September 2000, the Superior Court of the State of California approved the Peace Agreement and authorized the implementation of the Chino Basin Optimum Basin Management Program to protect and enhance the safe yield of the Chino Basin. The Peace Agreement II of 2007 is an update to the original agreement (CBWM, 2013). Prior to and following the Peace Agreement, numerous projects have been implemented to increase groundwater recharge while minimizing excess TDS concentrations in the groundwater of the Chino Basin. The CBWCD involved in a Four Party Agreement and has worked collaboratively with Chino Basin Watermaster, San Bernardino Flood Control District, and Inland Empire Utilities Agency to develop and implement a recharge master plan that was developed in 2007 and is updated every five years. Due to the extent of water challenges in the Chino Basin, a detailed summary of legal and engineering activities related to the Peace Agreement and the Recharge Master Plan will not be provided in this report. Additional information can be obtained by reviewing the References section of this report. The following tasks were completed as part of this project: • Assessment of existing watershed management efforts within the Chino/San Antonio Basins • Evaluation of watershed management efforts currently being planned and/or constructed by Chino Basin watershed management agencies, such as the Chino Basin Watermaster (CBWM), Inland Empire Water Utilities Agency (IEUA), City of Pomona, Monte Vista Water District (MVWD), San Bernardino County, Santa Ana Watershed Protection Authority (SAWPA), Metropolitan Water District of Southern California (SCMWD), and the Chino Basin Desalter Authority. • Assist Wagner & Bonsignore in development of a conceptual design of a water storage facility on a 15.76-acre property recently purchased by the CBWCD which is located at the junction of Chino and San Antonio Creeks south of Riverside Drive in unincorporated 1 San Bernardino County, CA. This property is referred to herein as the Confluence Regional Water Resource Project or the Confluence Project. • Identify potential water quality benefits of the Confluence Project and recommend a monitoring program for the project. • In addition to the Confluence Project, evaluate the potential for additional capture and recharge of basin flows that will reduce the overall salt content of the aquifers of Chino Basin. The assessment of existing and proposed recharge efforts within Chino Basin provides a basis for the conceptual design of the proposed Confluence Regional Water Resource Project. Figure 1 – Map of the Chino Basin (Source: Wildermuth et.al., 2010) 2 SECTION B ASSESSMENT OF EXISTING WATERSHED MANAGEMENT The Parties to the Peace Agreement have been working collaboratively to implement recommended recharge projects. Reports such as the 2013 Amendment to the 2010 Recharge Master Plan Update (Wildermuth Environmental, Inc., 2013) provide details on implementation progress and status reports are provided weekly (e.g. IEUA, 2018) and semi-annually (Wildermuth Environmental, Inc., 2017b). The 2013 Amendment to the 2010 Recharge Master Plan Update describes existing spreading basins (see Figure 2), enhancements to improve recharge basin performance, and recharge via aquifer storage and recovery (ASR). Lower Cucamonga Basins Figure 2 – Recharge Basins in the Chino Basin (Source: Wildermuth Environmental, 2013) One of the unintended consequences of water resources development projects from the 1950’s through the 1990’s was a loss of groundwater recharge due to concrete lining of San Antonio, Chino, Cypress, Cucamonga, Deer, Day, and San Sevaine Creeks. Historically, runoff from the 3 San Gabriel mountains flowed south into the alluvial deposits