We’re less than a month into the monsoon, and the Tucson area has already received more rain than the entire 2020 monsoon season. While the cooler days and rainstorms are a welcome sight for many, the heavy downpours have also caused flash flooding throughout the state.
On Thursday, July 15, the City of Flagstaff and Coconino County declared a state of emergency due to monsoonal flooding. This declaration came as videos were widely shared of flash floods damaging homes and vehicles in Flagstaff, worsened due to the nearby burn scars from Arizona’s drought-heightened wildfires.
Luckily, Tucson, Catalina and Oro Valley have not experienced extreme flooding, but the possibility remains due to the large burn scar from 2020’s Bighorn Fire, which burned nearly 120,000 acres of the Catalina Mountains. However, the Pima County Sheriff’s Department has already documented road closures and downed powerlines due to the monsoon. Golder Ranch Fire District and Northwest Fire crews have also had to assist drivers with their vehicles stuck in flooded streets.
“It doesn’t matter what kind of vehicle you have, please, turn around,” Northwest Fire District warned. “Find a detour instead of driving into a dangerous situation.”
In early July, the Pima County Board of Supervisors and Flood Control District sent information to nearly 1,000 property owners in districts 1, 3 and 4 who may be affected by flooding near the Bighorn Fire burn area.
“Although a year has passed since the fire, the risk of flooding and debris flows remains high, primarily due to the lack of significant rainfall over the past year, which has limited vegetation regrowth and left soil conditions unchanged since the fire,” a county memorandum read.
Locals may recall haunting footage from last year showing jet-black waters rushing down Canada Del Oro wash, choked with ash and burnt wood. Don Falk, professor in the School of Natural Resources and the Environment at the University of Arizona, said extreme wildfires can cause soil to become “hydrophobic,” meaning it won’t absorb water, leading to worse flash floods.
According to the county, after the Aspen Fire on Mount Lemmon in 2003, flash floods and mudflows resulted in at least one reported fatality and caused extensive property damage in watershed areas downstream of the burn area.
In response to these threats, the town of Oro Valley is providing free sandbags to residents who may need to protect areas of their homes from flooding. Due to a limited number of supplies, only Town of Oro Valley residents are eligible. Pickup is at Naranja Park (810 W. Naranja Drive) in the area known as the “Christmas tree recycling lot” while supplies last. Sandbags are self-service. Residents will need to bag and load their own sand, with a limit of 10 sandbags per vehicle.
The Town of Marana is also distributing sandbags for residents. Marana Public Works will assist town residents concerned with flooding by providing sandbag pick-up locations and offering pre-filled sandbags at the Marana Operations Center Yard (5100 W. Ina Road) and Marana Heritage River Park (12205 N. Tangerine Farms Road) while supplies last. There is also a limit of 10 sandbags per vehicle.
Pima County is providing a limited number of sandbags for impacted properties, available at the Department of Transportation facility (1313 S. Mission Road), Brandi Fenton Memorial Park (3482 E. River Road), in Catalina at the northwest corner of Golder Ranch Drive and Twin Lakes Drive, and in Summerhaven on Carter Canyon Road at the north side of Snyder Road and Lason Lane.
The Town of Oro Valley Stormwater Utility has also created a “Monsoon Preparedness Guide’’ with resources for residents. The Preparedness Guide recommends families to formulate an emergency plan, which includes identifying meeting locations both inside and outside of the neighborhood, making sure everyone in the household is familiar with alternate routes through town, and naming an out-of-area contact if your family gets split up. The Preparedness Guide also lists the “5 Ps” in the rare event of an evacuation: People (and pets), papers, prescriptions, pictures and personal computers.
Pima County also recommends homeowners purchase flood insurance, stating that new policies for flood insurance generally become effective following a 30-day waiting period. However, the Biggert-Waters Flood Insurance Reform Act of 2012 provided an additional exception to this requirement related to flooding caused by post-wildfire conditions, referred to as the Post-Wildfire Exception.
According to the National Weather Service, as of Friday, July 16, this July has already seen 1.5 inches of rain (as measured from the Tucson airport), beating out the .46 inches of rain seen all of last July. Every day for the rest of July and the first half of August are predicted to have a chance of rain.