Upper Santa Ana River Integrated Model Summary Report Part 1 of 5: Text DRAFT Prepared For: San Bernardino Valley Municipal Water District April 29, 2020 GEOSCIENCE Support Services, Inc. | P (909) 451‐6650 | F (909) 451‐6638 620 Arrow Highway, Suite 2000, La Verne, CA 91750 | Mailing: P.O. Box 220, Claremont, CA 91711 www.gssiwater.com Upper Santa Ana River Integrated Model - Summary Report DRAFT 29-Apr-20 THIS REPORT IS RENDERED TO SAN BERNARDINO VALLEY MUNICIPAL WATER DISTRICT AS OF THE DATE HEREOF, SOLELY FOR THEIR BENEFIT IN CONNECTION WITH ITS STATED PURPOSE AND MAY NOT BE RELIED ON BY ANY OTHER PERSON OR ENTITY OR BY THEM IN ANY OTHER CONTEXT. AS DATA IS UPDATED FROM TIME TO TIME, ANY RELIANCE ON THIS REPORT AT A FUTURE DATE SHOULD TAKE INTO ACCOUNT UPDATED DATA. THIS DOCUMENT HAS BEEN CHECKED FOR COMPLETENESS, ACCURACY, AND CONSISTENCY BY THE FOLLOWING PROFESSIONALS: ___________________________________ David Barnes, M.Eng. 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No portion of this report may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, electronic, photocopying, recording or otherwise EXCEPT for purposes of the project for which this document was produced. i Upper Santa Ana River Integrated Model - Summary Report DRAFT 29-Apr-20 UPPER SANTA ANA RIVER INTEGRATED MODEL SUMMARY REPORT CONTENTS EXECUTIVE SUMMARY ............................................................................................................... 1 1.1 Introduction ...................................................................................................................... 1 1.2 Conceptual Model of the Integrated SAR Model .............................................................. 2 1.3 Update of Existing Groundwater Models .......................................................................... 3 1.4 Construction and Calibration of the Chino Basin Model ................................................... 3 1.4.1 Chino Basin Model Initial Calibration Results ............................................................. 4 1.5 Upper Santa Ana River Watershed Model ........................................................................ 4 1.5.1 Watershed Model Calibration ..................................................................................... 4 1.6 Integrated SAR Model ....................................................................................................... 5 1.6.1 Aquifer Parameters ..................................................................................................... 6 1.6.2 Recharge and Discharge Terms ................................................................................... 7 1.6.3 Model Calibration ....................................................................................................... 7 1.6.3.1 Initial Condition Simulation ............................................................................. 7 1.6.3.2 Transient Calibration ....................................................................................... 8 1.6.3.2.1 Groundwater Elevations ........................................................................... 8 1.6.3.2.2 Underflow across Basin Boundaries ....................................................... 12 1.6.3.2.3 Streamflow .............................................................................................. 12 1.6.3.2.4 Water Balance ......................................................................................... 13 1.6.3.2.5 Cumulative Change in Groundwater Storage ......................................... 14 1.7 Predictive Scenarios ........................................................................................................ 14 1.8 Summary ......................................................................................................................... 15 INTRODUCTION ....................................................................................................................... 18 2.1 Integrated SAR Model Objectives ................................................................................... 19 2.2 Multi-Agency Cooperative Technical Effort .................................................................... 20 2.3 Previous Groundwater and Surface Water Models ........................................................ 20 ii Upper Santa Ana River Integrated Model - Summary Report DRAFT 29-Apr-20 2.4 Model Domain and Model Cell Size for the Integrated SAR Model ................................ 21 2.5 Model Integration Process .............................................................................................. 22 GEOLOGIC CONCEPTUAL MODEL OF THE INTEGRATED SAR MODEL ......................................... 23 3.1 Geography ....................................................................................................................... 23 3.2 Physiography ................................................................................................................... 24 3.2.1 Peninsular Ranges Geomorphic Province ................................................................. 25 3.2.2 Transverse Ranges Geomorphic Province ................................................................. 25 3.3 Geologic Overview .......................................................................................................... 26 3.3.1 Structural Rock Assemblages .................................................................................... 26 3.3.1.1 Peninsular Ranges Assemblage ..................................................................... 26 3.3.1.2 San Gabriel Mountains Assemblage .............................................................. 26 3.3.2 General Geologic Setting .......................................................................................... 27 3.3.2.1 Miocene and Older Undifferentiated Bedrock .............................................. 27 3.3.2.2 Pliocene to Miocene Sedimentary Rocks ...................................................... 27 3.3.2.3 Pleistocene Sedimentary Units ..................................................................... 28 3.3.2.4 Holocene and Pleistocene Deposits .............................................................. 29 3.3.3 Structural Geology .................................................................................................... 29 3.3.3.1 San Bernardino Basin Area and Yucaipa Basin .............................................. 29 3.3.3.2 Chino, Temescal, Rialto-Colton, and Riverside-Arlington Basins .................. 31 HYDROLOGIC CONCEPTUAL MODEL ......................................................................................... 32 4.1 Sources of Inflow and Outflow (Recharge and Discharge) .............................................. 32 4.1.1 Mountain Front Runoff ............................................................................................. 32 4.1.2 Precipitation .............................................................................................................. 33 4.1.3 Streamflow ................................................................................................................ 34 4.1.3.1 Inflow from the Surrounding Watershed ...................................................... 35 4.1.3.2 Local Runoff ................................................................................................... 35 4.1.3.3 Wastewater Discharges ................................................................................. 36 4.1.3.4 Rising Groundwater Discharge to Streamflow .............................................. 36 4.1.3.5 Diversions ...................................................................................................... 36 iii Upper Santa Ana River Integrated Model - Summary Report DRAFT 29-Apr-20 4.1.4 Artificial Recharge ..................................................................................................... 37 4.1.5 Anthropogenic Return Flow ...................................................................................... 37 4.1.6 Underflow Inflow ...................................................................................................... 38 4.1.7 Evapotranspiration .................................................................................................... 38 4.1.7.1 Aspen Riparian Vegetation Mapping and Consumptive Water Use ............. 39 4.1.7.2 Shallow Groundwater and Evapotranspiration Assessment by BGW ........... 41 4.1.7.3 Riparian Areas ............................................................................................... 42 4.1.7.4 Maximum Evapotranspiration Demand ........................................................ 44 4.1.8 Groundwater Pumping .............................................................................................. 46 4.2 Hydrostratigraphy ........................................................................................................... 47 4.2.1 Development of Unified Model Layers ..................................................................... 48 UPDATE OF EXISTING