Distressed vineyard in Coachella Valley, Calif. Picture taken by Kelly M. Grow of the California Department of Water Resources.
Folsom Lake
Low water drought conditions at Folsom Lake, California, in June 2021
Low water drought conditions at Folsom Lake, California, in June 2021
Coachella Valley
Drought distressed vineyard in California's Coachella Valley
Drought distressed vineyard in California's Coachella Valley
Lake Oroville
Extremely low water under the Enterprise Bridge at Lake Oroville during 2021 drought
Extremely low water under the Enterprise Bridge at Lake Oroville during 2021 drought
Los Angeles
Trees dying due to drought - Griffith Park in Los Angeles, California
Trees dying due to drought - Griffith Park in Los Angeles, California
The USGS closely monitors the occurence and effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information about long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues and competing interests in times of drought.
California's Monthly Streamflow
California's Monthly Streamflow
This graph shows the amount of streamflow measured at USGS California stream gages. This includes precipitation in the form of rain, snowmelt, subsurface stormflow, and groundwater discharge that eventually becomes water flowing in streams and rivers. A portion of precipitation is lost to evapotranspiration or becomes storage in wetlands, lakes, reservoirs, and aquifers.
California Water Data
California Water Data
Basic hydrologic data collection, processing, analysis, dissemination, and archiving are major parts of the California Water Science Center program.
What is Drought?
A drought is a period of drier-than-normal conditions that result in water supply problems and can impact humans and other water-dependent systems. When rainfall is less than normal for several weeks, months, or years, the flow of streams and rivers declines, water levels in lakes and reservoirs fall, and the depth to water in wells increases. If dry weather persists and water-supply problems develop, the dry period can become a drought.
During times of drought, vegetation is visibly dry, stream and river flows decline, water levels in lakes and reservoirs fall, and the depth to water in wells increases. As drought persists, longer-term impacts can emerge, such as land subsidence, seawater intrusion, and damage to ecosystems. Unlike the immediate impacts of drought, however, long-term impacts can be harder to see, but more costly to manage in the future.
Drought Comparisons
Because of their duration and severity in terms of both lack of rainfall and streamflow, the 1928-34 drought, which lasted 7 years, and the 1987-92 drought, which lasted 6 years, are compared to the 2012-16 drought, which lasted 5 years, to assess similarities and differences.
>> Explore Historical Droughts
Streamflow
The amount of water flowing in a stream is an important parameter in assessing drought impact severity. The amount of streamflow is dependent upon many factors including the amount, location and type of precipitation (rain or snow); rainfall rates; the amount of base flow (i.e. contribution of groundwater to streamflow); antecedent soil moisture conditions; the amount of empty surface water reservoir storage; the magnitude to which groundwater aquifers are drawn down; watershed geology and topography; the level of urbanization and human water use in the watershed; and the amount and type of landscape and cultivated plant cover. We track both monthly and annual streamflow data.
Surface Water
Careful observation and analysis of the movement and condition of surface water is essential for understanding this resource, especially during times of drought. The California Water Science Center uses a network of more than 500 streamgages to collect real-time data on surface water at locations across the state.
Groundwater
Groundwater provides drinking water for a large portion of the nation's population, supplies business and industries, and is used extensively for irrigation. Groundwater and surface water are part of a single resource that exchanges in both directions. For example, on average half of the annual streamflow across the United States comes from groundwater, and surface water is an important source of groundwater recharge that sustains aquifers. But what happens to this resource during drought?
Sources/Usage: Public Domain. View Media Details
Below are multimedia items associated with this project.
CochellaValley_dead_vines.jpg
Distressed vineyard in Coachella Valley, Calif. Picture taken by Kelly M. Grow of the California Department of Water Resources.
Oroville_2021drought.jpg
Lake Oroville showing extremely low water under the Enterprise Bridge during 2021 drought. Photo by Kelly M. Grow of the California Department of Water Resources.
Lake Oroville showing extremely low water under the Enterprise Bridge during 2021 drought. Photo by Kelly M. Grow of the California Department of Water Resources.
Folsom_2021drought.jpg
Low water drought conditions at Folsom Lake, California, on June 23, 2021. Photo by Florence Low / California Department of Water Resources.
Low water drought conditions at Folsom Lake, California, on June 23, 2021. Photo by Florence Low / California Department of Water Resources.
FL_Griffith_Park-drought.jpg
Dying trees at Griffith Park in Los Angeles, California. Photo by Florence Low / California Department of Water Resources.
Dying trees at Griffith Park in Los Angeles, California. Photo by Florence Low / California Department of Water Resources.
Tracking California's Water
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. California is experiencing a drought, surface water, rainfall, groundwater and snowpack have been at historic lows. This shortage is impacting water users and natural systems across the state.
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. California is experiencing a drought, surface water, rainfall, groundwater and snowpack have been at historic lows. This shortage is impacting water users and natural systems across the state.
Drought, Drinking Water and Natural Environments
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
California Drought, Huntington Lake (August, 2014)
Extremely low water levels at Huntington Lake, CA in August, 2014 during the severe drought California faced from 2012 -2016. Located in the Sierra Nevada mountain range, Huntington Lake is a reservoir operated by the U.S. Bureau of Reclamation.
Extremely low water levels at Huntington Lake, CA in August, 2014 during the severe drought California faced from 2012 -2016. Located in the Sierra Nevada mountain range, Huntington Lake is a reservoir operated by the U.S. Bureau of Reclamation.
The USGS closely monitors the occurence and effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information about long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues and competing interests in times of drought.
California's Monthly Streamflow
California's Monthly Streamflow
This graph shows the amount of streamflow measured at USGS California stream gages. This includes precipitation in the form of rain, snowmelt, subsurface stormflow, and groundwater discharge that eventually becomes water flowing in streams and rivers. A portion of precipitation is lost to evapotranspiration or becomes storage in wetlands, lakes, reservoirs, and aquifers.
California Water Data
California Water Data
Basic hydrologic data collection, processing, analysis, dissemination, and archiving are major parts of the California Water Science Center program.
What is Drought?
A drought is a period of drier-than-normal conditions that result in water supply problems and can impact humans and other water-dependent systems. When rainfall is less than normal for several weeks, months, or years, the flow of streams and rivers declines, water levels in lakes and reservoirs fall, and the depth to water in wells increases. If dry weather persists and water-supply problems develop, the dry period can become a drought.
During times of drought, vegetation is visibly dry, stream and river flows decline, water levels in lakes and reservoirs fall, and the depth to water in wells increases. As drought persists, longer-term impacts can emerge, such as land subsidence, seawater intrusion, and damage to ecosystems. Unlike the immediate impacts of drought, however, long-term impacts can be harder to see, but more costly to manage in the future.
Drought Comparisons
Because of their duration and severity in terms of both lack of rainfall and streamflow, the 1928-34 drought, which lasted 7 years, and the 1987-92 drought, which lasted 6 years, are compared to the 2012-16 drought, which lasted 5 years, to assess similarities and differences.
>> Explore Historical Droughts
Streamflow
The amount of water flowing in a stream is an important parameter in assessing drought impact severity. The amount of streamflow is dependent upon many factors including the amount, location and type of precipitation (rain or snow); rainfall rates; the amount of base flow (i.e. contribution of groundwater to streamflow); antecedent soil moisture conditions; the amount of empty surface water reservoir storage; the magnitude to which groundwater aquifers are drawn down; watershed geology and topography; the level of urbanization and human water use in the watershed; and the amount and type of landscape and cultivated plant cover. We track both monthly and annual streamflow data.
Surface Water
Careful observation and analysis of the movement and condition of surface water is essential for understanding this resource, especially during times of drought. The California Water Science Center uses a network of more than 500 streamgages to collect real-time data on surface water at locations across the state.
Groundwater
Groundwater provides drinking water for a large portion of the nation's population, supplies business and industries, and is used extensively for irrigation. Groundwater and surface water are part of a single resource that exchanges in both directions. For example, on average half of the annual streamflow across the United States comes from groundwater, and surface water is an important source of groundwater recharge that sustains aquifers. But what happens to this resource during drought?
Sources/Usage: Public Domain. View Media Details
Below are multimedia items associated with this project.
CochellaValley_dead_vines.jpg
Distressed vineyard in Coachella Valley, Calif. Picture taken by Kelly M. Grow of the California Department of Water Resources.
Distressed vineyard in Coachella Valley, Calif. Picture taken by Kelly M. Grow of the California Department of Water Resources.
Oroville_2021drought.jpg
Lake Oroville showing extremely low water under the Enterprise Bridge during 2021 drought. Photo by Kelly M. Grow of the California Department of Water Resources.
Lake Oroville showing extremely low water under the Enterprise Bridge during 2021 drought. Photo by Kelly M. Grow of the California Department of Water Resources.
Folsom_2021drought.jpg
Low water drought conditions at Folsom Lake, California, on June 23, 2021. Photo by Florence Low / California Department of Water Resources.
Low water drought conditions at Folsom Lake, California, on June 23, 2021. Photo by Florence Low / California Department of Water Resources.
FL_Griffith_Park-drought.jpg
Dying trees at Griffith Park in Los Angeles, California. Photo by Florence Low / California Department of Water Resources.
Dying trees at Griffith Park in Los Angeles, California. Photo by Florence Low / California Department of Water Resources.
Tracking California's Water
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. California is experiencing a drought, surface water, rainfall, groundwater and snowpack have been at historic lows. This shortage is impacting water users and natural systems across the state.
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. California is experiencing a drought, surface water, rainfall, groundwater and snowpack have been at historic lows. This shortage is impacting water users and natural systems across the state.
Drought, Drinking Water and Natural Environments
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
This short video is one of a series of four total shorts highlighting USGS water science in California's Delta region. The Sacramento-San Joaquin Delta is the hub of the state's water system. Water quality touches on all aspects of life. Teams of U.S.
California Drought, Huntington Lake (August, 2014)
Extremely low water levels at Huntington Lake, CA in August, 2014 during the severe drought California faced from 2012 -2016. Located in the Sierra Nevada mountain range, Huntington Lake is a reservoir operated by the U.S. Bureau of Reclamation.
Extremely low water levels at Huntington Lake, CA in August, 2014 during the severe drought California faced from 2012 -2016. Located in the Sierra Nevada mountain range, Huntington Lake is a reservoir operated by the U.S. Bureau of Reclamation.