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 USGS California Water Science Center maintains nearly 500 streamgages that collect data to determine the amount of water flowing in rivers and streams in California. Automatic alerts are transmitted when water levels change rapidly and/or reach flood stage. These alerts help emergency managers assess potential hazardous conditions near the gage or for downstream locations.
USGS WaterNow is a service that sends data showing current water conditions directly to your mobile phone upon your request.
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.
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
San Joaquin-Sacramento Basin Rain Flood Duration Skew Study
Development of Precipitation-Runoff Modeling System (PRMS) for the Yuba River Basin, Northeastern California, with application for streamflow predictability and flood forecasting
Development of Precipitation-Runoff Modeling System (PRMS) for the Kings River Basin, California, with application for streamflow predictability and flood forecasting
Development of Precipitation-Runoff Modeling System (PRMS) for the Tuolumne River Basin, Central California, with application for streamflow predictability and flood forecasting.
Post-Fire Flooding and Debris Flow
- Overview
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 USGS California Water Science Center maintains nearly 500 streamgages that collect data to determine the amount of water flowing in rivers and streams in California. Automatic alerts are transmitted when water levels change rapidly and/or reach flood stage. These alerts help emergency managers assess potential hazardous conditions near the gage or for downstream locations.
USGS WaterNow is a service that sends data showing current water conditions directly to your mobile phone upon your request.
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.Sections of Fashion Valley Road, San Diego, were closed by flooding of the San Diego River. Closed roads were a common scene in San Diego and throughout California during the El Niño-related storms Jan. 6-7, 2016. Hydrographers from the Poway Field Officers closely monitored high-flow conditions throughout the storms. (USGS photo by Dianna Crilley) (Public domain.) 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.
- Science
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...San Joaquin-Sacramento Basin Rain Flood Duration Skew Study
The U.S. Army Corps of Engineers (USACE) is conducting a hydrologic analysis of floodplain areas protected by the federal-state levee system within the San Joaquin-Sacramento drainage basins.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
his 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 (by...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... - Data
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