2009 Station Fire, Arroyo Seco, Pasadena California


Rainfall on steep burned basins can transform into potentially dangerous flash floods and debris flows. In 2009, the Station Fire burned 160,000 acres in the San Gabriel Mountains. Vegetation has started to return, but it can take many years for a basin to fully recover from the effects of fire.

The U. S. Geological Survey has installed instruments in a small basin of Arroyo Seco above Pasadena, CA.

Purpose of Monitoring

Data collection at this site supports research on the hydrologic factors that control debris-flow initiation in burned areas. The USGS conducted debris-flow monitoring at this site after the fire from 2009 to 2011. The USGS reestablished the monitoring site in the fall of 2015 to understand the effects of vegetation recovery on debris-flow susceptibility.

Instruments and are used to monitor and detect changes in local conditions, including

Current Monitoring Status


Frequency of Web Graph Updates

Most of the measurements are taken at 1-minute intervals and data are transmitted hourly and displayed on graphs. Updates may be interrupted occasionally by instrument, computer, or network malfunctions.


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