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 flowing in rivers and streams. 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.
California Streamgage Network
Streamgage sites provide continuous scientific data such as water level (stage) and flow rate, chemistry, and temperature in the Nation’s rivers. This critical information is used for many purposes, from flood forecasting to recreational planning. Water agencies rely on this information to assess the availability and quality of water supplies. It also helps us understand how streams are affected by human activities and by climate change.
See Current California Water Conditions >>
Automated Local Evaluation in Real-Time (ALERT) Gages
Many of the USGS streamgages in California are Automated Local Evaluation in Real-Time (ALERT) gages. ALERT gages are designed to send an automated warning when water levels reaches predetermined levels or change rapidly.
These water levels can signify potentially hazardous conditions for downstream locations. ALERT data are streamed in real-time to the National Water Information System (NWIS-web), and are used by the National Weather Service for model forecasting and to issue flood warnings.
The USGS California Water Science Center recently added several ALERT gages and precipitation stations in the burn areas of the Valley and Butte Wildfires to help monitor the potential for mudslides and debris flows, and to provide early flood warning to downstream areas.
Below are other science projects associated with this project.
California Flood Science
Flood Inundation Mapping Science
Flood Inundation Mapping (FIM) Program
- 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 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 flowing in rivers and streams. 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.
Sources/Usage: Public Domain.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. (Public domain.) California Streamgage Network
Sources/Usage: Public Domain.The colored dots on this map depict streamflow conditions as a percentile, which is computed from the period of record for the current day of the year. Only stations with at least 30 years of record are used. The white circles indicate other stations that were not ranked in percentiles either because they have fewer than 30 years of record or because they report parameters other than streamflow. Some stations, for example, measure stage only. (Public domain.) Streamgage sites provide continuous scientific data such as water level (stage) and flow rate, chemistry, and temperature in the Nation’s rivers. This critical information is used for many purposes, from flood forecasting to recreational planning. Water agencies rely on this information to assess the availability and quality of water supplies. It also helps us understand how streams are affected by human activities and by climate change.
See Current California Water Conditions >>
Automated Local Evaluation in Real-Time (ALERT) Gages
Many of the USGS streamgages in California are Automated Local Evaluation in Real-Time (ALERT) gages. ALERT gages are designed to send an automated warning when water levels reaches predetermined levels or change rapidly.
These water levels can signify potentially hazardous conditions for downstream locations. ALERT data are streamed in real-time to the National Water Information System (NWIS-web), and are used by the National Weather Service for model forecasting and to issue flood warnings.
The USGS California Water Science Center recently added several ALERT gages and precipitation stations in the burn areas of the Valley and Butte Wildfires to help monitor the potential for mudslides and debris flows, and to provide early flood warning to downstream areas.
- Science
Below are other science projects associated with this project.
California Flood Science
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...Flood Inundation Mapping Science
When planning for a flood, there are three key questions that must be answered: What areas will be flooded? How deep will the flood waters get? When will the flood arrive? Historical flooding can help a community anticipate how much impact similar flood events could have, but there are other methods and tools that can provide more accurate and nuanced estimations of a wide variety of flood...Flood Inundation Mapping (FIM) Program
Floods are the leading cause of natural-disaster losses in the U.S. More than 75 percent of declared Federal disasters are related to floods, and annual flood losses average almost $8 billion with over 90 fatalities per year. Although the amount of fatalities has declined due to improved early warning systems, economic losses continue to rise with increased urbanization in flood-hazard areas. - Data
- Multimedia
- Web Tools
- News