Floods of the Southwest - Lessons from Flagstaff
Updated: Dec 5, 2021
“How is this happening? Where did all this water come from? And the power of it…” said JoAnna Daulton Ignace, a Flagstaff resident of over forty years. She watched torrents of water sweep across her property and into her home.
Ignace vividly recalled the day her house flooded. She watching at a distance as the flood overtook her home. A river formed within minutes and rushed through the trees. She stood alone. The water separated her from her husband and son who both stood trapped inside their garage.
Earlier that summer day, Ignace had gone on a bike ride on the mountain trails near her house. She remarked to herself how saturated the ground still seemed from a recent rain. Puddles dotted the usually dry trail system.
As she left home later that day, it started raining. Hard. She said she never thought about flooding being a risk in her area.
While she was out, Ignace received a call from her husband. She said he was screaming hysterically, “Our house is flooding JoAnna, our house is flooding!”
“I drove like a bat out of hell,” said Ignace.
She arrived on her street and was met by a crowd of emergency vehicles blocking the road, and even they were unable to get through the water to her husband. Over five feet of water surged across her backyard.
After the flood had receded a couple feet. Video credit: JoAnna Ignace.
Though the flooding this summer wreaked havoc in Flagstaff, flooding in Northern Arizona and the larger Southwest region is actually not unusual.
Peter Friederici, professor at Northern Arizona University and coordinator of the Sustainable Communities Program, said this is an inherent result of the monsoonal weather pattern unique to this region.
“It’s just the nature of an arid landscape that then has a lot of water falling in a short period,” said Friederici.
Although this monsoon pattern naturally causes some flooding, Friederici said in addition to the notably intense monsoons this year, poor city planning and wildfires can enhance the effects of flooding.
Since other areas across the Southwest deal with similar arid conditions, wildfires, and the need to plan city layouts accordingly, Flagstaff can serve as a valuable example of how communities can be impacted by these issues and what communities can do moving forward.
In contrast to this remarkably rainy year, Coconino County dubbed the 2019 and 2020 monsoon seasons “nonsoon” seasons because they were the two driest years on record. But as dry as those years were, flooding still occurred in town, according to the County. This foreshadowed that in a normal year, and especially in a wet year, flooding could be disastrous. And this past summer it was.
Friederici said one reason for these extreme floods is that intense wildfires, such as the Museum Fire that happened near Flagstaff in 2019, remove vegetation that would naturally help water soak into the soil. Intense wildfires can also cause the soil to actually repel water. Burned soil can become as repellent as pavement, according to the National Weather Service.
Brady Smith, public affairs officer for the Coconino National Forest, said that in addition to these issues, infrastructure located at the base of steep slopes will deal with flooding during monsoon events, regardless of whether there’s been a fire on those slopes.
Jenny Niemann, the climate program manager at the City of Flagstaff, said that a lot of the flooding Flagstaff experienced this past summer was not due to the Museum Fire. She said that although the flooding near Forth Street was indeed enhanced by the burn scar, the flood shown in the viral “Prius video” near Steves Boulevard was actually not related to the fire. In this video, a Prius is swept away by a river that was once a neighborhood street. But this street is several blocks east of the area impacted by the burn scar, said Niemann.
Instead, the flooding responsible for carrying the car away was the result of a 500- or 400-year rain event, according to Niemann. These “events” are intense monsoonal rainstorms that don’t occur very often. Niemann explained that a 500-year event has a 0.2% chance of occurring each year.
Similarly, the flooding Ignace experienced wasn’t the result of being located downslope from a burn scar. Ignace’s home is located just outside Cheshire. This is not one of the areas of Flagstaff that typically experiences seasonal flooding and not located near a recent burn scar.
Ignace’s property was built in 1961 and she said it has only flooded twice before. Ignace said previous flooding was due to culverts, which are large metal pipes that allow water to pass under a road or through a ravine. On both occasions, these culverts on neighboring properties became blocked by debris, causing the water in those channels to overflow.
This year, with record rainfall, another culvert complication ensued. Ignace said that neighboring culverts were overturned by the force of the water rushing down the nearby slope and pinned against a fence, allowing more water pressure to build up. Eventually, it all gave way, causing the massive torrent that smashed through Ignace’s house and property.
“I don’t know. I think it was a perfect storm,” said Ignace.
Niemann said that as the climate warms in the future, we will see precipitation patterns changing, resulting in more extreme weather events and stronger storms. Although it’s important to recognize monsoonal flooding is a natural part of living in this region, it’s evident how extreme monsoon events coupled with fire and location of infrastructure can be even more devastating.
The reality is that many in Flagstaff and the larger Southwest region will continue to deal with flash floods, both as an inherent part of living in this region and as other factors, including more intense wildfires and the effects of climate change, enhance these floods.
“You sit there, and you watch your home and your furniture being scooped up in a dump truck, wet and dripping,” said Ignace. “It’s… I don’t know how to describe it.”
But despite the devastating loss of many of her belongings and the extensive damage done to her home, Ignace said she chooses to keep going and not live in fear.
“Even as tired as I am today, I gotta move forward,” said Ignace.
So many in Flagstaff and the Southwest have been affected by flooding in devastating and deeply personal ways. Even so, Ignace said she’s finding hope in this shattering moment of loss, hope in the rebuilding of her home and the belief that things will get better.
Events like these prompt us to consider questions about how we as a society can become more resilient to the changes in our environment as a whole. Our climate is changing. Fires and flooding will become more frequent and extreme. There are adaptive measures like forest thinning, controlled burns, and rethinking infrastructure that can mitigate flooding in our communities. But more broadly, how are we as individuals and communities going to make choices for the future that will make us more resilient to these changes and allow us to prosper?
Solutions to these complex problems will come through community and local government collaboration to implement current scientific knowledge, rethinking infrastructure locations, better land management and support of vulnerable members of the community.
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