A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
Monitoring high-water events
USGS hydrologic technician measures streamflow at the Cosumnes River at Michigan Bar, California on December 31, 2022. This was the highest direct measurement ever recorded at this site—63,700 cubic feet per second—in over 100 years of record.
USGS hydrologic technician measures streamflow at the Cosumnes River at Michigan Bar, California on December 31, 2022. This was the highest direct measurement ever recorded at this site—63,700 cubic feet per second—in over 100 years of record.
Throughout the nation, the USGS operates a streamgage network in near real-time that helps emergency managers and others protect life and property due to floods and other water-related hazards. The USGS California Water Science Center maintains nearly 500 streamgages that provides key streamflow and water level data for flood forecasters, the public, and emergency managers at the federal, state, county, and local levels. During any given water year, USGS hydrographers verify the continuous data at each streamgage by inspecting water level sensor operation and measuring the range of observed flows, including at high flows.
USGS WaterAlert automatically sends email or SMS text messages when certain parameters, as measured by a USGS real-time data-collection station, exceed user-defined thresholds.
Sources/Usage: Public Domain. View Media Details
Atmospheric Rivers (AR’s)
Atmospheric rivers are long, narrow corridors moving through the atmosphere where water vapor is transported at high rates. These AR’s move moisture from the tropics in the Pacific over to the western coast of the United States. AR’s are responsible for great quantities of rain and have been identified to have a significant role in generating flooding across the western United States. They can also fuel strong winter storms that contribute to beneficial increases in snowpack.
Fall and Winter Weather: El Niño
El Niño is a naturally occurring event characterized by unusually warm ocean temperatures in the Equatorial Pacific. El Niño has come to refer to a whole complex of Pacific Ocean sea-surface temperature changes and global weather events. If El Niño conditions are present during the winter, the jet stream pattern over the U.S. shifts and can result in a wetter-than-average winter across the southern tier of the U.S., including portions of California.
On October 11, 2018, the National Oceanic and Atmospheric Administration Climate Prediction Center issued an El Niño watch for the Northern Hemisphere. All four Niño values increased over the last month indicating a developing El Niño. El Niño is favored to form in the next couple of months and continue through the Northern Hemisphere winter 2018-19 (70-75% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period). Typical El Niño patterns in California include increased rainfall with the potential for accompanying floods, landslides, and coastal erosion. The effects are variable across the state and are more predictable in Southern California. For fall and winter 2018, NOAA’s temperature outlook suggests warmer than normal climate patterns and normal to wetter than normal precipitation patterns in California.
The California Water Science Center studies various aspects of floods. You can find additional flood science below.
California Streamgage Information
To help emergency managers and others protect life and property due to floods and other water-related hazards, the USGS delivers a continuous source of streamflow information. The U.S. Geological Survey has been measuring streamflow in the U.S. for over 120 years. We operate more than 7,500 streamgages in the U.S. and nearly 500 in California that collect data to determine the amount of water...
Development of Precipitation-Runoff Modeling System (PRMS) for the Yuba River Basin, Northeastern California, with application for streamflow predictability and flood forecasting
Reservoirs in the Yuba River Basin are operated by the US Army Corps of Engineers (USACE) as part of the Feather-Yuba Forecast Coordinated Operations Program, and play an important role in flood management, water quality, and the health of fisheries as far downstream as the Sacramento-San Joaquin Delta. The basin has been developed for hydropower and irrigation diversions, so that measured...
Development of Precipitation-Runoff Modeling System (PRMS) for the Kings River Basin, California, with application for streamflow predictability and flood forecasting
This study will provide an analysis tool for forecasting seasonal and longer term streamflow variations, and for evaluating climate and land cover variations in the Kings River Basin. This study will directly or indirectly address several water-resource issues identified in the USGS Science Strategy document (USGS, 2007): drinking water availability, the suitability of aquatic habitat for biota...
Development of Precipitation-Runoff Modeling System (PRMS) for the Tuolumne River Basin, Central California, with application for streamflow predictability and flood forecasting.
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...
Post-Fire Flooding and Debris Flow
Fast-moving, highly destructive debris flows triggered by intense rainfall are one of the most dangerous post-fire hazards. The risk of floods and debris flows after fires increases due to vegetation loss and soil exposure. Cases of sudden and deadly debris flow are well documented along the western United States, particularly in Southern California. These flows are a risk to life and property...
Below are multimedia items associated with this project.
Santa Maria River Flooding
A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
Post-Wildfire Debris Flood: 2016 Fish Fire, Van Tassel Canyon, CA
The June 2016 Fish Fire burned over 12 km^2 in Los Angeles County, California. After the fire, the USGS installed an automated rain-triggered camera and laser stage gage to monitor post-wildfire flooding and debris flow in Van Tassel Canyon near Azusa. This video shows the peak flow triggered by an intense rainstorm on January 20, 2017.
The June 2016 Fish Fire burned over 12 km^2 in Los Angeles County, California. After the fire, the USGS installed an automated rain-triggered camera and laser stage gage to monitor post-wildfire flooding and debris flow in Van Tassel Canyon near Azusa. This video shows the peak flow triggered by an intense rainstorm on January 20, 2017.
Post-fire Debris Flow
Debris Flow in Cable Canyon following the 2003 Old Fire in the San Bernardino Mountains, California.
Debris Flow in Cable Canyon following the 2003 Old Fire in the San Bernardino Mountains, California.
Throughout the nation, the USGS operates a streamgage network in near real-time that helps emergency managers and others protect life and property due to floods and other water-related hazards. The USGS California Water Science Center maintains nearly 500 streamgages that provides key streamflow and water level data for flood forecasters, the public, and emergency managers at the federal, state, county, and local levels. During any given water year, USGS hydrographers verify the continuous data at each streamgage by inspecting water level sensor operation and measuring the range of observed flows, including at high flows.
USGS WaterAlert automatically sends email or SMS text messages when certain parameters, as measured by a USGS real-time data-collection station, exceed user-defined thresholds.
Sources/Usage: Public Domain. View Media Details
Atmospheric Rivers (AR’s)
Atmospheric rivers are long, narrow corridors moving through the atmosphere where water vapor is transported at high rates. These AR’s move moisture from the tropics in the Pacific over to the western coast of the United States. AR’s are responsible for great quantities of rain and have been identified to have a significant role in generating flooding across the western United States. They can also fuel strong winter storms that contribute to beneficial increases in snowpack.
Fall and Winter Weather: El Niño
El Niño is a naturally occurring event characterized by unusually warm ocean temperatures in the Equatorial Pacific. El Niño has come to refer to a whole complex of Pacific Ocean sea-surface temperature changes and global weather events. If El Niño conditions are present during the winter, the jet stream pattern over the U.S. shifts and can result in a wetter-than-average winter across the southern tier of the U.S., including portions of California.
On October 11, 2018, the National Oceanic and Atmospheric Administration Climate Prediction Center issued an El Niño watch for the Northern Hemisphere. All four Niño values increased over the last month indicating a developing El Niño. El Niño is favored to form in the next couple of months and continue through the Northern Hemisphere winter 2018-19 (70-75% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period). Typical El Niño patterns in California include increased rainfall with the potential for accompanying floods, landslides, and coastal erosion. The effects are variable across the state and are more predictable in Southern California. For fall and winter 2018, NOAA’s temperature outlook suggests warmer than normal climate patterns and normal to wetter than normal precipitation patterns in California.
The California Water Science Center studies various aspects of floods. You can find additional flood science below.
California Streamgage Information
To help emergency managers and others protect life and property due to floods and other water-related hazards, the USGS delivers a continuous source of streamflow information. The U.S. Geological Survey has been measuring streamflow in the U.S. for over 120 years. We operate more than 7,500 streamgages in the U.S. and nearly 500 in California that collect data to determine the amount of water...
Development of Precipitation-Runoff Modeling System (PRMS) for the Yuba River Basin, Northeastern California, with application for streamflow predictability and flood forecasting
Reservoirs in the Yuba River Basin are operated by the US Army Corps of Engineers (USACE) as part of the Feather-Yuba Forecast Coordinated Operations Program, and play an important role in flood management, water quality, and the health of fisheries as far downstream as the Sacramento-San Joaquin Delta. The basin has been developed for hydropower and irrigation diversions, so that measured...
Development of Precipitation-Runoff Modeling System (PRMS) for the Kings River Basin, California, with application for streamflow predictability and flood forecasting
This study will provide an analysis tool for forecasting seasonal and longer term streamflow variations, and for evaluating climate and land cover variations in the Kings River Basin. This study will directly or indirectly address several water-resource issues identified in the USGS Science Strategy document (USGS, 2007): drinking water availability, the suitability of aquatic habitat for biota...
Development of Precipitation-Runoff Modeling System (PRMS) for the Tuolumne River Basin, Central California, with application for streamflow predictability and flood forecasting.
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...
Post-Fire Flooding and Debris Flow
Fast-moving, highly destructive debris flows triggered by intense rainfall are one of the most dangerous post-fire hazards. The risk of floods and debris flows after fires increases due to vegetation loss and soil exposure. Cases of sudden and deadly debris flow are well documented along the western United States, particularly in Southern California. These flows are a risk to life and property...
Below are multimedia items associated with this project.
Santa Maria River Flooding
A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
A USGS hydrologic technician takes streamflow measurements during flooding of the Sisquoc River, a tributary of the Santa Maria River, near the town of Garey in Santa Barbara County.
Post-Wildfire Debris Flood: 2016 Fish Fire, Van Tassel Canyon, CA
The June 2016 Fish Fire burned over 12 km^2 in Los Angeles County, California. After the fire, the USGS installed an automated rain-triggered camera and laser stage gage to monitor post-wildfire flooding and debris flow in Van Tassel Canyon near Azusa. This video shows the peak flow triggered by an intense rainstorm on January 20, 2017.
The June 2016 Fish Fire burned over 12 km^2 in Los Angeles County, California. After the fire, the USGS installed an automated rain-triggered camera and laser stage gage to monitor post-wildfire flooding and debris flow in Van Tassel Canyon near Azusa. This video shows the peak flow triggered by an intense rainstorm on January 20, 2017.
Post-fire Debris Flow
Debris Flow in Cable Canyon following the 2003 Old Fire in the San Bernardino Mountains, California.
Debris Flow in Cable Canyon following the 2003 Old Fire in the San Bernardino Mountains, California.