Groundwater

A numerical modeling approach was used to quantify groundwater conditions and land subsidence spatially along the Delta-Mendota Canal. In addition, selected management alternatives for controlling land subsidence were evaluated.

The objective of this study is to provide downscaled ensemble projections of climate and hydrology for the next century for the state of California with specific application to the San Francisco Bay Area.

In areas adjacent to the Delta-Mendota Canal (DMC), extensive groundwater withdrawal from the San Joaquin Valley aquifer system has caused areas of the ground to sink as much as 10 feet, a process known as land subsidence. This could result in serious operational and structural issues for the Delta-Mendota Canal (DMC). In response, the USGS is studying and providing information on groundwater...

The USGS has a long history of collecting water-level data in the Antelope Valley groundwater basin. Previous water-level contour maps for Antelope Valley were published by the USGS in cooperation with the Antelope Valley – East Kern Water Agency as Open-File Reports 80-1222, 86-498 and 98-4022 using water-level data collected in 1979, 1984 and 1996, respectively. An updated water-level contour...

The Bureau of Land Management (BLM) manages the Dos Palmas Oasis complex on the northeastern side of the Salton Sea for the maintainence of threatened and endangered species. This Oasis complex represents a rare area of riparian/wetland habitat in the midst of an extremely arid desert region. Anthropogenic development of water resources during the 1900s depleted natural groundwater supplies...

The Tulare Lake basin in the southern Central Valley of California is heavily dependent upon groundwater for drinking water supply but groundwater in this basin is threatened by a wide array of issues. Groundwater aquifers in the alluvial fan sediments derived from the Sierra Nevada on the eastern side of the Tulare Lake basin are highly productive aquifers that are vulnerable to contamination...

The Mojave Basin Area was adjudicated in 1993 and the Mojave Water Agency (MWA) was appointed as Watermaster to ensure that water rights are allocated according to the Court Judgment (Riverside County Superior Court, 1996). Established in 1960, the southwestern boundary of MWA’s management area is not a hydrologic boundary but instead coincides roughly with the boundary between San Bernardino and...

Pesticides are used throughout the State of California in both urban and agricultural settings and are routinely detected in surface water. Each year, new pesticides are introduced to the market and often become detected in surface water. It can take several years or more for routine monitoring programs to acquire the capability to detect new and understudied pesticides of concern because...

Runoff from snowmelt and rainfall in the Tuolumne River basin plays a significant role in irrigation and domestic water supply for Turlock and Modesto Irrigation Districts, City of Modesto and the San Francisco Bay Area. This area experiences very different seasonal and decadal climate events which are known to affect the timing and volumes of runoff. Land-cover change alone, such as the Rim Fire...

Between 1956 and 1972, the Stringfellow Hazardous Waste Site, Riverside County, Calif., discharged approximately 34 million gallons of industrial wastes to unlined surface impoundments located at the head of Pyrite Canyon. Contaminants from the site have been detected as far as 4 miles downgradient near the Santa Ana River. Perchlorate in excess of the California Maximum Contaminant Level of 6...

The Joshua Basin Water District (JBWD) is implementing an artificial groundwater recharge program to reverse the decline of groundwater levels and to store water in the Joshua Tree groundwater subbasin of the Morongo groundwater basin (~100 mi east of Los Angeles, CA).

The Water Replenishment District of Southern California (WRD) is planning to construct an advanced water treatment facility and three supplemental injection wells in a recharge area in the coastal plain of Los Angeles County.