Photo courtesy Coconino County.
COCONINO COUNTY — On August 7, 2024, Post-wildfire flooding from the Pipeline Fire burn scar was successfully contained by the Copeland Flood Mitigation System that was completed about a month ago.
As one of seven post-wildfire flood mitigation systems recently constructed by the Coconino County Flood Control District, the Copeland system integrates over 50 acres of watershed restoration with roughly 9,000 feet of buried storm drain pipe. This system was engineered to capture about 2,000 cubic-feet per-second of water—over 3 times the average flow of the Verde River—and mitigate the devastating impacts of post-wildfire flooding in the area. On August 7th, after a series of monsoon storms saturated the burn scar on the slopes upstream, the system received its first post-wildfire flood flows.
“Everything worked as intended,” said Lucinda Andreani, Coconino County Flood Control District Administrator. “The flows we observed on August 7th were by no means the largest we’ve seen in the area, but they were significant enough to indicate that the system is functioning well.”
Andreani added that by the time they reached the storm drain inlet, the post-wildfire flood flows were relative debris-free—which demonstrated the success of watershed restoration measures designed to reduce downstream sediment and debris.
“It’s no easy feat to engineer a system that seamlessly incorporates the natural hydrology of the landscape with flood mitigation infrastructure,” Andreani said. “But after two major wildfires over nine impacted watersheds, our engineering partners have become experts at integrating post-wildfire watershed restoration and flood mitigation.”
Since the 2022 Pipeline Fire, the Coconino County Flood Control District has secured roughly $125 million in federal grants to address post-wildfire flooding across nine watersheds—many of which were also impacted by the 2010 Schultz Fire.
To date, the District has completed about $75 million in post-wildfire flood mitigation, which includes over 250 acres of watershed restoration, over 200 flood control structures, and nearly 5 miles of flood conveyance infrastructure. The Copeland system is the seventh complete system the District has delivered since they secured funding less than two years ago.
“We still have more to do,” Andreani added. “We’re pursuing post-wildfire flood mitigation systems in two more watersheds—Government Tank and Peaceful Way—and in many ways these systems are posed to be our most complex projects yet.”
Despite the demonstrated success of the Copeland system, Andreani urges residents to remain vigilant.
“Even with mitigation, the risk of post-wildfire flood mitigation remains very real. Heavy enough rainfall can overwhelm even the largest of systems. But for the majority of flood events, we now have systems that will mitigate impacts to most of the neighborhoods and buy us time as the watersheds heal.”
For more information, visit Coconino.az.gov/SchultzPipelineFloodArea.