Hydrogeologic Characterization of the Yucaipa Groundwater Subbasin

Scientific Investigations Report 2021-5118-A
Prepared in cooperation with San Bernardino Valley Municipal Water District
By: , and 



Water management in the Santa Ana River watershed in San Bernardino and Riverside Counties in southern California (fig. A1) is complex with various water purveyors navigating geographic, geologic, hydrologic, and political challenges to provide a reliable water supply to stakeholders. As the population has increased throughout southern California, so has the demand for water. The Yucaipa groundwater subbasin (hereafter referred to as “Yucaipa subbasin”), one of nine groundwater subbasins in what the California Department of Water Resources (DWR) refers to as the Upper Santa Ana Valley groundwater basin (California Department of Water Resources, 2016; fig. A1; the DWR naming convention is used within this report), is no exception; steady population growth since the 1940s and changes in water use have forced local water purveyors to regularly adapt their water infrastructure. Water demands within the Yucaipa subbasin have historically been supplied by groundwater, but water imported via the California State Water Project has augmented the total water supply through direct use and through anthropogenic recharge at the Wilson Creek and Oak Glen Creek spreading basins since 2002. Overall demand for groundwater continues to rise, and local water managers are concerned that despite the influx of imported water, groundwater levels may decline to a point where producing water will be uneconomical, severely limiting the ability of local agencies to meet water-supply demand.

To better understand the hydrogeology and water resources in the Yucaipa subbasin, the U.S. Geological Survey (USGS) initiated a study in cooperation with the San Bernardino Valley Municipal Water District (SBVMWD) to characterize and model the hydrologic system of the Yucaipa subbasin and the surrounding Yucaipa Valley watershed (YVW; fig. A2). To gain this comprehensive understanding, a three-dimensional (3D) hydrogeologic framework model (HFM; Cromwell and Matti, 2022) was constructed to quantify the structure and extent of hydrogeologic units in the YVW; the hydrologic system was conceptualized and quantified (described in chapter A); and the Yucaipa Integrated Hydrological Model (YIHM; described in chapter B) was developed to simulate the integrated surface-water and aquifer systems, including natural and anthropogenic recharge and discharge throughout the study area during 1947–2014.

Suggested Citation

Cromwell, G., Engott, J.A., Alzraiee, A.H., Stamos, C.L., Mendez, G.O., Dick, M.C., and Bond, S., 2022, Hydrogeologic characterization of the Yucaipa groundwater subbasin, chap. A in Cromwell, G., and Alzraiee, A.H., eds., Hydrology of the Yucaipa groundwater subbasin—Characterization and integrated numerical model, San Bernardino and Riverside Counties, California: U.S. Geological Survey Scientific Investigations Report 2021–5118–A, 81 p., https://doi.org/10.3133/sir20215118A.

ISSN: 2328-0328 (online)

Table of Contents

  • Introduction 
  • Hydrogeology 
  • Water Budget 
  • Groundwater Levels, Flow, and Movement 
  • Hydrologic Flow Barriers 
  • Water Chemistry 
  • Summary 
  • References Cited 
  • Appendix A1. Tables
Publication type Report
Publication Subtype USGS Numbered Series
Title Hydrogeologic characterization of the Yucaipa groundwater subbasin
Series title Scientific Investigations Report
Series number 2021-5118
Chapter A
DOI 10.3133/sir20215118A
Year Published 2022
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) California Water Science Center
Description Report: vii, 81 p., and data release
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details