A monsoon storm that dropped more than 4 inches of rain in parts of Maricopa overnight provided an early test for ongoing flood-control work along the Santa Rosa Wash. City and flood district officials say the system worked largely as intended. 

Two roads in the Rancho El Dorado neighborhood, including the South Loop over the wash, were closed for several hours this morning after flooding overtook them. City officials said temporary closures in low-lying areas are expected during heavy rains. 

“It’s standard for our emergency management team to drive around town after a storm like last night to check for hazards,” city spokeswoman Monica Williams told InMaricopa. “We have no reported issues with city sidewalks, but individual homeowners’ associations may have their own maintenance needs.” 

In The Villages at Rancho El Dorado, floodwater almost covered benches on some of the low-lying walkways between neighborhoods.

Maricopa uses parks and open spaces as water retention areas, explained Williams. “Those areas are doing exactly what they were designed to do when we get large amounts of rain at one time,” she said.

David Alley, district manager for the Maricopa Flood Control District, said the storm allowed crews to see how the nearly complete $500,000 Santa Rosa Wash improvement project handled a major rain event. 

“For the most part, it seems to have worked exactly the way we designed it to work,” said Alley this morning, on his way to tour the rain water’s impact. “The low-flow channel we’re building is meant to manage treated water from Global Water Resources, not capture all stormwater from an event like this, but the way the water ran today will help us fine-tune certain areas.” 

The low-flow channel project, now about 90% complete, is intended to confine Global Water’s regular water releases to the center of the wash, preventing erosion, overgrowth and making maintenance easier. 

City officials reminded drivers not to attempt to cross flooded roads.  

“It’s impossible to know what might be lurking beneath the surface, and cars can force water out of its natural path toward retention areas, potentially causing damage to nearby homes or property,” said Williams.

According to meteorologists at Fox 10 Phoenix, the epicenter of last night’s storm, which swept through large portions of Central Arizona, was centered precisely on Maricopa’s East Side, which received more rain than anywhere else.