Tucson’s city Department of Transportation and Mobility is rolling out its annual program to warn drivers away from dips flooded by monsoon rains.

Starting June 17, the Street Maintenance Division will be on call 24/7 through mid-September, ready to block off flooded dip crossings using hundreds of preventative barriers as part of Operation Splash.

The city will be providing free self-serve sandbags in the east parking lot of Hi Corbett Field, 700 S. Randolph Way, at Reid Park. Residents can prepare for summer storms, establishing barricades against potential runoff and flooding that could damage homes.

Sandbags can be picked up all day, every day, with no more than 10 sandbags taken per vehicle, officials said.

Residents are advised to bring their own shovels and gloves for to assemble sandbags. Pima County and Oro Valley have also announced sandbag pickup points.

Since the program began in 2016, the city Transportation Department has handed out about 177,200 sandbags, officials said.

During severe weather storms, city transportation workers use National Weather Service radar and the Pima County Regional Flood Control District ALERT System to determine the sites where barricades should prevent motorists from entering flooded roadways. 

A map of where barricades were placed in 2023 is posted online.