Monsoon flooding: What Arizona cities are doing to keep drivers safe

Posted at 6:28 PM, Jun 12, 2018
and last updated 2018-06-13 14:36:30-04

It's a symptom of summer in the Valley; Monsoon storms, dumping on streets and at times, stranding drivers.

But how are cities working to keep roads dry and drivers safe?

"It's like a big puzzle," said Jayme Chapin, a senior civil engineer with the City of Glendale. 

"You can fix one thing, but that might impact this other thing -- so it's kind of trying to put all those pieces together," she said.

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Using computer modeling software to measure and predict rainfall, Chapin and her colleagues decide how wide roads should be, their slope, and where retention basins and inlets -- known as scuppers -- should be placed to minimize flooding. 

"If we designed these streets so they never saw water on them, then we couldn't afford to build them," she said. 

Chapin said cities across the Valley follow similar standards when it comes to designing roads with an infrastructure to mitigate flooding. 

FULL SECTION: Arizona monsoon

"In a ten-year storm, you'll have that area in the middle [of the road] that's high and dry, and then in a hundred-year event you'll have water in the roadway," Chapin said, adding that even with those guidelines there should never be more than eight inches of water in a road's deepest part. 

Although current design standards have been around for more than 20 years, Chapin said cities are still working to upgrade older roads and other infrastructure.

Glendale spends "millions" each year on upgrades, and the Maricopa County Flood Control District provides grant money to cities for improvements and new projects. 

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If there's a consistent problem spot near you, Chapin said you should report it to your city's engineering department. Sometimes cities aren't aware there's a problem until a complaint is filed.