Periodically over the next few months, Arizona will be at risk of flooding, filled with astonishing volumes of water as a result of unpredictable summer storms.
Thanks to a complex multi-agency system, Arizona is better able to track rain levels and flooding than it was two decades ago.
The Arizona Flood Warning System (AFWS) involves government agencies such as the National Weather Service down to county flood-control districts. Joint efforts are coordinated by the AFWS, a task assigned by statute to the Arizona Department of Water Resources (ADWS).
“After the 1993 floods, the governor had a task force looking at improving the system,” Brian Cosson, ADWS flood warning coordinator, said. “And that’s what happened. The infrastructure was expanded to include (signal) repeaters to send out data, mostly to the National Weather Service and to end-users like emergency managers.”
The 1993 Arizona floods captured the attention of citizens and state legislators alike. That year, raging floodwaters cascading down the Salt River destroyed the Phoenix-Tempe bridge that was under construction at the time.
Until then, flood-warning systems were scattershot; some counties relied on rain gauges and signal repeaters. Others -- mostly rural districts with scarce resources -- could do little to warn residents of impending floods. Since 1993, 750 rain-and-stream flow gauges have been installed in critical positions around Arizona, along with more than 60 signal repeaters so crucial data gets to where it is needed.
“We are a small player in what’s called the Arizona Flood Warning System,” Cosson said. “But we help coordinate it all. We’re the only agency that is the repository of all that information.”
3550 N Central Ave
Phoenix, AZ 85012