2009 Station Fire, Arroyo Seco, Pasadena, California

Monitoring post-fire flash floods and debris flows

  • View of monitoring basin in Arroyo Seco, Pasadena, CA


Rainfall on steep burned basins can quickly transform into potentially dangerous flash floods and debris flows. Arroyo Seco is one of many steep canyons burned in the 160,000-acre Station Fire of August and September 2009. This area experienced several large debris flows during the first winter storm season after the fire.

The U.S. Geological Survey (USGS) has installed instruments to monitor floods debris flows in a small 0.01 km2 sub-basin of Arroyo Seco.

Purpose of Monitoring

Data collection at this site is intended to advance the understanding of post-fire runoff, erosion, and debris-flow generation processes and to provide information from the burned area to the National Weather Service for warning decision-making.

The instruments were installed in November 2009 and are used to monitor:

Current Monitoring Status


Frequency of Web Graph Updates

Graphs are updated approximately every 5 minutes. Typically the most recent data on the graph lags the current time by 5 to 10 minutes. Updates may be interrupted occasionally by instrument, computer, or network malfunctions.

Monitoring performed in Cooperation with

National Oceanic and Atmospheric Association

Other USGS real-time monitoring in Arroyo Seco

For more information


This monitoring site was operated as part of a research project. Active data collection may be discontinued at any time in the future.

These data are preliminary and have not received final approval. Data relayed by radio or other telemetry have received little or no review. Inaccuracies in the data may be present because of instrument malfunctions or physical changes at the measurement site. Subsequent review may result in significant revisions to the data.

Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences.

Contact Information

Mailing Address

U.S. Geological Survey
Geologic Hazards Team
Box 25046, MS 966
Denver, CO 80225