Rapid Deployment of Flood Warning System for County of Sonoma Following Devastating Wildfires

In October 2017, the Sonoma County region experienced damaging firestorms. The resulting fire burn scars and ground conditions throughout the Tubbs and Nuns area left the region highly vulnerable to life-threatening flash flooding and debris flows during heavy rainstorms. As they headed into the rainy season, Sonoma County and City of Santa Rosa officials knew that a flood warning network was needed as quickly as possible to assist the County and National Weather Service in detecting potential flooding conditions.

Led by Sonoma County Water Agency and working collaboratively with a team from OneRain Incorporated and other local agencies, a  plan was put in place to implement a new flood warning network for the region. Within 3 months of having Board authorization for the project, a new fully functional ALERT2™ Flood Warning network was operational. 22 site locations, within and downstream of the areas burned, now have automated streamflow and rainfall gauges installed. OneRain’s Contrail® software collects, processes, and disseminates the data in real time to alert City and County officials of the potential dangers during rain storms, and provides data feeds to weather forecasters who are responsible for sending out alerts to residents when flash floods or debris flows may be imminent.


“The need on the heels of the October fires was imminent, and the pace at which we had to act was daunting. OneRain definitely stepped up to the plate to help us navigate this rapid deployment of our gauge network. Their expertise and professionalism were invaluable throughout the process,” said Jay Jasperse,  Chief Engineer, Sonoma County Water Agency.


The data collected from the rainfall and stream gauges are used by the National Weather Service (NWS) in developing their hazardous weather advisories, alerts and warnings. Keeping the community safe, informed and prepared is of high importance to the County and City officials.  The real-time rainfall and streamflow data is also available to the public at https://sonoma.onerain.com/.



In a press release issued by the County of Sonoma and City of Santa Rosa, Brian Garcia, Warning Coordination Meteorologist with the National Weather Service said, “Knowing what is going on in real time is vitally important to the issuance of life-saving warnings, such as flash flood warnings. During rain storms we continually monitor the network of instrumentation across Sonoma County to maintain situational awareness.

The new post-wildfire rain and stream gauge system and website installed by the Sonoma County Water Agency is part of an early warning system for flooding and public safety, and to improve its overall flood control capabilities. Expansion of the network is already underway, with the addition of new rain and stream gauge sites as well as soil moisture sensors.

Read the full Sonoma County Press Release (download PDF):  Rainfall and Stream Gauges Provide Early Flood Monitoring System for Flash Floods and Debris Flows in Burn Areas, or visit the Sonoma County website here.


About OneRain Incorporated
Since 1992, OneRain has been providing solutions that optimize water management, heighten regulatory compliance, achieve successful civil works, and save lives. Headquartered in Longmont, Colorado, OneRain’s software and services deliver mission critical information to serve clients responsible for flood early warning, dam safety and reservoir operations, water resources, stormwater and wastewater management. For more information, visit www.onerain.com or call 800-758-RAIN (7246).

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