Salinity trends in a groundwater system supplemented by 50 years of imported Colorado River water

Environmental Science & Technology Water
By: , and 



The Indio subbasin of the Coachella Valley is a desert area of southern California where a growing population depends primarily on groundwater for drinking and agricultural uses. The aquifer system has been supplemented with Colorado River water through managed recharge and widespread irrigation since the mid-20th century. We use a combination of geochemical modeling and trend analysis to identify changes in total dissolved solids through time, elucidate the sources of dissolved solids, and quantify the extent of contributions from those sources throughout the Indio subbasin. We conclude that recharged Colorado River water is the primary source and driver of increasing salinity, particularly in areas immediately downgradient from the recharge locations and in the eastern part of the subbasin away from the recharge ponds due to irrigation using imported water. Other contributions of dissolved solids to groundwater resources include geothermal waters, wastewater effluent, and agricultural return flow, although their effects are more localized. This study presents a broadly applicable framework for identifying sources of dissolved solids in groundwater wells and salinity trends at a regional scale in a large data set.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Salinity trends in a groundwater system supplemented by 50 years of imported Colorado River water
Series title Environmental Science & Technology Water
DOI 10.1021/acsestwater.3c00239
Volume 3
Issue 10
Year Published 2023
Language English
Publisher ACS Publications
Contributing office(s) California Water Science Center
Description 12 p.
First page 3253
Last page 3264
Country United States
State California
Other Geospatial Coachella Valley
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