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The original item was published from 8/6/2019 9:43:45 AM to 1/1/2020 12:00:00 AM.

News Flash

Flood Control District

Posted on: August 6, 2019


Daniel Henz receiving Award

In 2007, the National Hydrological Warning Council created an awards program to highlight excellent work and innovation in the field of hydrologic warning. This year, at the conference and exposition in Louisville, Kentucky, the Flood Control District of Maricopa County’s (FCD) Flood Warning Branch received the Operational Excellence Award for its ALERT (Automated Local Evaluation in Real-Time) network. This is awarded to an organization that has developed and maintained an exceptional hydrologic warning system.

Starting in 1980 with one lonely station on Smith Peak and one at the Durango Complex, FCD’s ALERT network was born. Now, with over 400 stations all over Maricopa as well as five adjoining counties, our ALERT network is the largest in the United States. These stations provide on-demand weather, rainfall and streamflow information for the public, city and county emergency departments as well as the National Weather Service (NWS). FCD uses and provides this information to monitor and operate our dams, basins and channels to identify hazardous areas and transportation routes that may require evacuation or closure as well as support flood response and emergency action plans.

The ALERT system combines three types of instruments: rain gages, weather stations and water-level stations. Rain gages (spelled gage by the USGS) are tipping-bucket style. Water fills the bucket when it is full it tips measuring 0.04” of rain. Gages send information in real-time. Weather stations measure temperature, humidity, wind speed/direction, barometer pressure, and solar radiation. The information from these stations is updated every fifteen minutes. Water-level stations measure water depth and flow from pressure sensors. Real-time information is sent back or on an incremental basis.


ALERT stations collect data and transmit measurements via FM radio to repeaters and receivers. Data then arrive separately at the FCD, Maricopa County Department of Emergency Management and the NWS Phoenix where it is decoded and processed. It is then stored on internet servers at the Flood Control District and is accessible to the public via their home computers, phones and other mobile devices.

As Maricopa County continues to grow, the ALERT network also grows. Three new gages have already been added in the burn scar area of the recent Woodbury Fire and five more are scheduled for installation in other parts around the county. Continued collaboration with emergency managers and first responders ensures that people and property remain safe from floods.

For more information on the FCD ALERT system or to check out the real-time rainfall data visit our website at

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