Please visit the Bighorn Fire Flood Risk page for details specific to the Bighorn Fire.
Wildfires raise your flood risk by leaving the ground charred, barren, and unable to absorb water. That means even light rain can potentially turn into a financially devastating flash flood or mudflow and can occur with very little warning. This increased runoff may continue for several years after an area has burned and until vegetation is reestablished. A post-fire flood video from the Canada Del Oro Wash in Tucson, and a post-fire flood video from Cochiti Canyon in New Mexico is a good example of what can happen after wildfires. The District works with the Office of Emergency Management to provide flood alerts to residents within burned watersheds, where possible. To receive these alerts, you must sign up with MyAlerts and provide the property address(es) you are concerned about. For more information please call the Pima County Regional Flood Control District at (520) 724-4600.
See below for important fact sheets:
Floods Follow Fires - El aumento en el Riesgo de Inundacion Despues de un Incendio
Understanding Mudflows - Las Avalanchas de lodo
Post-Fire Debris Flows
Debris flows are a common occurrence after an area has burned. As water runs downhill through burned areas, it can create erosion and undercut previously stable areas which causes large amounts of burned material (ash, sand, silt, rocks, trees) to become loose. As water and the material begin to move, the risk of damage to downhill areas increases.
A Post-Wildfire Debris-Flow study highlights what may be expected due to the changing of hydrologic conditions to the landscape.
Be prepared - Create an Emergency Response Plan
Due to the topography and proximity to mountainous areas in Pima County, there is sometimes little to no warning of impending flash floods or debris flows. In the event of moderate to heavy rainfall it is best to take any emergency steps necessary to protect your life and property. Plan in advance to move away from the area and have a safety plan already in place. Plan ahead by creating an Emergency Response Plan.
Be Flood Safe
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. It is important to Be Flood Safe ahead of a rain storm.
Inundation Areas
The District's use of MyAlerts is largely limited to specific watercourses where we have a stream gage and sufficient floodplain modeling to determine the likely area of impact downstream of the stream gage. Clicking on the link for a specific watercourse below will take you to a page with detailed information about the messages one can expect to receive, steps to take when you receive a specific message, and flood safety information specific to that area.
Sandbags
Pima County is providing a limited number of sandbags for impacted properties, available at:
- Department of Transportation facility at 1313 S. Mission Road (724-6410);
- Brandi Fenton Memorial Park in the northwest dirt parking lot;
- South side of Ina Road just east of Pima Canyon Drive;
- In Catalina at the northwest corner of Golder Ranch Drive and Twin Lakes Drive;
- In Summerhaven on Carter Canyon Road at the north side of Snyder Road and Lason Lane; and
- The Town of Oro Valley is providing sandbags at Naranja Park in the Christmas tree drop off lot located just north of the Archery Range along the entry drive.