Coachella Valley Water District Engineer’s Report on Water Supply and Replenishment Assessment 2016-2017 • Mission Creek Subbasin Area of Benefit • West Whitewater River Subbasin Area of Benefit • East Whitewater River Subbasin Area of Benefit Prepared By: & April 2016 eN Q)N >. >0) ..0 "_N "'0 O-..:r Q) \' (f) 0 co"- a. LL Z ~ "'OW a.. ~ "~~ o~ 0 0:: COACHELLA VALLEY WATER DISTRICT BOARD OF DIRECTORS John Powell ...................................................................................................................President Peter Nelson ..........................................................................................................Vice President Ed Pack ........................................................................................................................... Director G. Patrick O'Dowd............................................................................................................ Director Cástulo Estrada ............................................................................................................... Director OFFICERS & COUNSEL Jim Barrett ........................................................................................................ General Manager Robert Cheng .................................................................................... Assistant General Manager Jeffry F. Ferre ................................................................................................Best Best & Krieger ENVIRONMENTAL SERVICES Steve Bigley........................................................................... Director of Environmental Services Ivory Reyburn ..................................................................................Water Resources Supervisor ENGINEERING Mark L. Johnson .......................................................................................Director of Engineering FINANCE Kay Godbey ....................................................................................................Director of Finance Thomas Rice...................................................................................................... Financial Analyst Engineer's Report on Water Supply and Replenishment Assessment 2016-2017 Mission Creek, West Whitewater River, and East Whitewater River Subbasin Areas of Benefit TABLE OF CONTENTS TABLE OF CONTENTS Page CHAPTER I - EXECUTIVE SUMMARY.................................................................................... I-1 A. Mission Creek Subbasin Area of Benefit ..................................................................... I-1 B. West Whitewater River Subbasin Area of Benefit........................................................ I-2 C. East Whitewater River Subbasin Area of Benefit......................................................... I-3 CHAPTER II - INTRODUCTION ..............................................................................................II-1 A. History and Legal Basis of the Groundwater Replenishment Program ........................II-1 B. Definition of Overdraft and Critical Overdraft...............................................................II-2 C. Changing Conditions...................................................................................................II-3 D. Sustainable Groundwater Management Act ................................................................II-4 CHAPTER III - COACHELLA VALLEY GROUNDWATER BASIN ..........................................III-1 A. The Coachella Valley and its Groundwater ................................................................III-1 B. Subbasins and Subareas ...........................................................................................III-2 C. Groundwater Storage Capacity ................................................................................III-12 D. Water Supply ...........................................................................................................III-12 E. Land Subsidence .....................................................................................................III-16 CHAPTER IV - GROUNDWATER REPLENISHMENT PROGRAM........................................ IV-1 A. Summary .................................................................................................................. IV-1 B. History ...................................................................................................................... IV-1 C. Replenishment Water Source(s) ............................................................................... IV-4 D. Replenishment Assessment................................................................................... .IV-10 CHAPTER V - MISSION CREEK SUBBASIN AREA OF BENEFIT ......................................... V-1 A. Management Area and Area of Benefit ...................................................................... V-1 B. Water Supply and Use ............................................................................................... V-1 C. Groundwater Replenishment...................................................................................... V-5 D. Aquifer Conditions...................................................................................................... V-7 E. Replenishment Assessment..................................................................................... V-11 F. Conclusions and Recommendations........................................................................ V-14 CHAPTER VI - WEST WHITEWATER RIVER SUBBASIN AREA OF BENEFIT .................... VI-1 A. Management Area and Area of Benefit ..................................................................... VI-1 B. Water Supply and Use .............................................................................................. VI-2 C. Groundwater Replenishment..................................................................................... VI-4 D. Aquifer Conditions..................................................................................................... VI-9 E. Replenishment Assessment.................................................................................... VI-14 F. Conclusions and Recommendations....................................................................... VI-17 CHAPTER VII - EAST WHITEWATER RIVER SUBBASIN AREA OF BENEFIT ................... VII-1 A. Management Area and Area of Benefit .................................................................... VII-1 B. Water Supply and Use ............................................................................................. VII-1 C. Groundwater Replenishment.................................................................................... VII-4 D. Aquifer Conditions.................................................................................................... VII-6 E. Replenishment Assessment................................................................................... VII-13 F. Conclusions and Recommendations...................................................................... VII-16 CHAPTER VIII - BIBLIOGRAPHY........................................................................................ VIII-1 APPENDIX A - 2015 COACHELLA VALLEY PRECIPITATION AND STREAM FLOW DATA Engineer's Report on Water Supply and Replenishment Assessment 2016-2017 Mission Creek, West Whitewater River, and East Whitewater River Subbasin Areas of Benefit i FIGURES Page Figure III-1 Coachella Valley Groundwater Subbasin .........................................................III-3 Figure III-2 Approximate Extent of Shallow, Semi-Perched Aquifer..................................III-17 Figure III-3 Generalized Stratigraphic Column: Thermal Subarea ...................................III-18 Figure V-1 Groundwater Level Changes in Mission Creek Subbasin Management Area: 2014 to 2015........................... V-15 Figure V-2 Groundwater Level Changes in Mission Creek Subbasin Management Area: 2005 to 2015........................... V-16 Figure V-3 Mission Creek Subbasin Management Area Artificial Replenishment Quantities and Groundwater Level Hydrograph .............................................................. V-17 Figure V-4 Mission Creek Subbasin Management Area Change in Groundwater in Storage................................................................ V-18 Figure VI-1 Groundwater Level Changes in West Whitewater River Subbasin Management Area: 2014 to 2015 ............ VI-18 Figure VI-2 Groundwater Level Changes in West Whitewater River Subbasin Management Area: 2005 to 2015 ............ VI-19 Figure VI-3 West Whitewater River Subbasin Management Area Artificial Replenishment Quantities and Groundwater Level Hydrograph....... VI-20 Figure VI-4 West Whitewater River Subbasin Management Area Change in Groundwater in Storage............................................................... VI-21 Figure VII-1 Groundwater Level Changes in East Whitewater River Subbasin Management Area: 2014 to 2015 ............ VII-17 Figure VII-2 Groundwater Level Changes in East Whitewater River Subbasin Management Area: 2005 to 2015 ............ VII-18 Figure VII-3 2015 Artesian Conditions (Elevations Above Ground Surface) in the East Whitewater River Subbasin Area of Benefit.......................................... VII-19 Figure VII-4 East Whitewater River Subbasin Management Area Change in Groundwater in Storage.............................................................. VII-20 Figure VII-5 Whitewater River Subbasin Change in Water Levels: