U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2005–3046

April 2005

WATER PROGRAMS

IN CALIFORNIA

Printed on recycled paper

California is threatened by many natural hazards—fire, 

floods, landslides, earthquakes. The State is also threatened by longer-term problems, such as hydrologic 

effects of climate change, and human-induced problems, 

such as overuse of ground water and degradation of 

water quality. The threats and problems are intensified 

by increases in population, which has risen to nearly 

36.8 million. For the USGS California Water Science 

Center, providing scientific information to help address 

hazards, threats, and hydrologic issues is a top priority. To meet the demands of a growing California, USGS 

scientific investigations are helping State and local 

governments improve emergency management, optimize 

resources, collect contaminant-source and -mobility 

information, and improve surface- and ground-water 

quality. USGS hydrologic studies and data collection 

throughout the State give water managers quantifiable 

and detailed scientific information that can be used to 

plan for development and to protect and more efficiently 

manage resources. The USGS, in cooperation with state, 

local, and tribal agencies, operates more than 500 instrument stations, which monitor streamflow, ground-water 

levels, and surface- and ground-water constituents to 

help protect water supplies and predict the threats of 

natural hazards. The following are some of the programs 

implemented by the USGS, in cooperation with other 

agencies, to obtain and analyze information needed to 

preserve California’s environment and resources.

In 2004, the USGS California Water Science Center responded 

to potential dangers resulting from wild fires in southern California by rapidly deploying instruments to bolster the ALERT 

network and local agencies’ debris-flow and hydrologic-hazard 

warning systems. By coordinating with local, state, and federal 

emergency-management operations, the 

USGS was able to 

issue timely debrisflow watches and 

warnings, and maps 

detailing areas of 

potential landslides.

Ground-Water Resource Management

Water pumped from the Joshua Tree subbasin has been the 

sole source of water for the community of Joshua Tree in the 

southern Mojave Desert. To improve the long- term sustainability of this water supply, the USGS, in cooperation with 

the Joshua Basin Water 

District, defined the 

geohydrologic framework, determined the 

quantity and distribution 

of recharge, and developed a ground -water flow 

model that can be used 

to help manage the water 

resources of the region.

Statewide Ground-Water Assessment

In cooperation with the State of California, the USGS has 

embarked on a comprehensive assessment of ground -water 

quality for the entire state. The Ground -Water Ambient Monitoring and Assessment 

(GAMA) program will 

provide information to 

resource managers to 

address issues ranging 

from local water-supply 

problems to statewide 

resource management.

River Restoration

USGS scientists from three disciplines—geology, hydrology, 

and biology— collaborated to provide the Santa Monica Mountains Conservancy information on key scientific issues relevent 

to a proposed new park at the confluence of the 

Los Angeles River and 

the Arroyo Seco in Los 

Angeles. Information 

on faulting, earthquake 

ground motion, liquefaction, landsliding, 

hydraulics and water 

quality of surface and 

ground-water, wildlife 

colonization–extinction 

dynamics, wildlife corridors, wildlife reintroduction, non-native 

species, and potential restoration of 

local habitat and ecology was submitted to the Conservancy.

USGS California Water Science Center

Reducing Loss of Life and Property
Urban Encroachment on Farmland

Cities such as Modesto in California’s Central Valley have some 

of the highest growth rates in the Nation, resulting in a gradual 

urbanization of adjacent farmlands and an increased reliance on 

ground water. The USGS California Water Science Center, in 

cooperation with the Modesto Irrigation District, compiled nearly 

3,500 driller's logs. USGS scientists are analyzing the logs to 

help develop a detailed computer model of the ground-water system. The model will be used to evaluate water-resources management strategies and ensure adequate water supplies. 

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USGS California Water Science Center

USGS California Water Science Center funding

Mercury Contamination

Mercury contamination from historical gold mines is a potential 

risk to human health and the environment. The USGS, in cooperation with local, state, and other federal agencies, is investigating mercury contamination in the Bear River and Yuba River 

watersheds. Data from the Bear−Yuba and from other USGS 

studies have been used by local and state agencies to issue 

fish consumption advisories 

for water bodies in northern 

California. USGS results have 

also been used by other federal 

agencies to prioritize mine 

sites for remediation.

For more information contact:

Michael V. Shulters, Director

USGS California Water Science Center

shulters@usgs.gov (916) 278-3026

6000 J Street, Placer Hall

Sacramento, CA 95819

http://ca.water.usgs.gov/