From the website:
Many people do not associate Arizona with flooding, but a 2017 analysis determined that Pima County was the eighth deadliest county in the nation for flood related deaths in the preceding 20 years. That normally dry wash on your property or roadway could present a very real danger to you in times of floods. These floods can happen any time of the year - during a heavy summer monsoon storm, or during a long, slow winter storm. Flash floods can occur many miles away from the storm event that causes them.
Do not drive around a barricade. Barricades are there for your protection. If you come to a flooded roadway, STOP! The depth of water is not always obvious and the roadbed may have washed away under the flowing water. It only takes one foot of flowing water to sweep most vehicles downstream; low profile vehicles move more easily. Fast flowing water greatly increases the risk.
You can monitor the District's network of rain gages and stream gages in real time on your computer and using our mobile app. Go to the Precipitation and Streamflow page for more details and access to the maps.