Water-Level, Water-Quality and Land-Subsidence Studies in the Mojave River and Morongo Groundwater Basins

Science Center Objects

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. The population of the Mojave River and Morongo groundwater basins has grown rapidly during the last several decades, increasing from an estimated population of almost 273,000 in 1990 (Mojave Water Agency, 2004) to more than 453,000 in 2010 (Mojave Water Agency, 2014).  Increased demands on water supplies have caused groundwater-level declines of more than 100 feet (ft) in some areas of this desert between the 1950s and the 1990s (Stamos and others, 2001; Sneed and others, 2003).  

Groundwater Levels

Regional water-table maps of the Mojave River and Morongo groundwater basins have been published in reports by the U.S. Geological Survey (USGS) every two years since 1992.  The water-level studies include water-level contour maps drawn from data measured from wells during each study. Most of the studies demonstrate water-level changes by hydrographs that show long-term and short-term water-level changes, and by maps that compare water levels at individual wells between two consecutively published reports.

>> Mojave Groundwater-Level Studies

 

Groundwater Quality

Since 2000, the U.S. Geological Survey (USGS) has collected water-quality data annually from a network of wells and has provided quality-assurance for Mojave Water Agency (MWA) data that are stored in the USGS National Water Information System (NWIS) database.  The USGS compiled maps and time-series plots of concentrations of selected water-quality constituents (arsenic, boron, chromium-6, total chromium, dissolved oxygen, fluoride, iron, manganese, nitriate plus nitrite as nitrogen, total dissolved solids, uranium, and vanadium) in the Mojave River and Morongo groundwater basins using data collected by the USGS and MWA from 2000 to 2012. 

>> Mojave Groundwater-Quality Studies

 

Land Subsidence

Subsidence, in the vicinity of dry lakebeds, within the Mojave River and Morongo groundwater basins has been evaluated using InSAR, ground-based measurements, geology, and analyses of water levels between 1992 and 2009 (years in which InSAR data were collected). The investigation focused on determining the location, extent, and magnitude of changes in land-surface elevation.

>> Mojave Land Subsidence Studies