Images

Standard configuration of a Sacramento-San Joaquin Delta flow and water quality monitoring station.  The U.S. Geological Survey (USGS) has operated and maintained a monitoring network in the Sacramento-San Joaquin Delta since the 1970’s.

The extensive withdrawal of groundwater from the unconsolidated deposits of the San Joaquin Valley has caused widespread land subsidence—locally exceeding 8.5 meters (m) between 1926 and 1970 (Poland and others, 1975; fig. 2), and reaching 9 m by 1981 (Ireland, 1986).

Juvenile sand lance (Ammodytes hexapterus) (top) and surf smelt (Hypomesus pretiosus) (bottom) collected on Bainbridge Island, Washington. Scale is in inches.

Generalized surface geology of the Anza–Terwilliger study area, Riverside and San Diego Counties, California (modified from
Rogers, 1965).

One of the wells that's part of the groundwater monitoring network in Anza Valley, CA.

Malakoff Diggins State Historic Park

In 2012, the Groundwater Ambient Monitoring & Assessment Priority Basin Project (GAMA-PBP) began water-quality assessments of shallow aquifers, the groundwater resources typically used for private domestic and small system drinking-water supplies.

The All-American Canal (AAC) in southern Imperial County, California, has historically been unlined, resulting in substantial losses to seepage. In 2006, the Imperial Irrigation District, under a contract with the United States Bureau of Reclamation, initiated a project to build a concrete-lined canal parallel to 23 miles of the earthen AAC.

Location map showing the location of facilities along the Colorado River and Yuma agricultural area adjacent to the United States-Mexico Border (USBR, 2011).

Gold pan with more than 30 grams of mercury from 1 kilogram of mercury-contaminated sediments collected in a drainage tunnel.

A USGS Hydrologist purges a groundwater monitoring well in preparation for water-quality sampling in the Imperial Sand Dunes Recreation area, Imperial Valley, California.  This sampling was done as part of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.

The Imperial Sand Dunes Recreational Area, located in Imperial County in the far southeast corner of California. It is home to a groundwater well field that is part of the U.S. Bureau of Reclamation's Lower Colorado Water Supply Project.

The Central Valley Hydrologic Model (CVHM) is built on knowledge from USGS and other Federal, State, and local studies. The CVHM was constrained by comparing simulated and historically observed groundwater levels, streamflows, and subsidence.

A USGS Hydrologist re-develops a monitoring well to ensure a good hydraulic connection is present between the perforations in the well and surrounding aquifer.  This work was being done as part of a groundwater system characterization and groundwater quality study being conducted along the All-American Canal that runs through the area.

A scientist from the USGS California Water Science Center taking well water sample in California.

A USGS Hydrologist collects water-quality samples as part of a wellbore characterization test at site LCWSP2 of the Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project study.

The All-American Canal in Imperial County, California near the border of Arizona and Mexico. Water discharging from well LCWSP2 can be seen on the far side of the canal.

Aerial view of the Iron Gate Dam and Hatchery along the Klamath River near Hornbrook, California.  A series of hydroelectric facilities (JC Boyle, Copco No. 1, Copco No. 2, and Iron Gate) separate the Klamath River into upper and lower basins.

Recording location and water-level data at a groundwater monitoring site in the Imperial Sand Dunes Recreation area, Imperial County, California. The work is being done as part of a water quality and groundwater system characterization study along the All-American Canal that runs through the area.

USGS scientist collecting water samples from an amphibian monitoring site in Livermore, California.

Stream gage #10254005 located near Westmorland, CA, on the eastern shore of the Salton Sea, now sits out of the water as the Salton Sea continues to evaporate and the shoreline retreats.