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Flagstaff’s major flood mitigation projects are nearing completion this year, but the prospect of a wetter-than-average monsoon season could complicate the final stages.

City staff and the National Weather Service provided an update to the city council on Tuesday, May 27, highlighting the progress of the Spruce Wash suite of projects and the outlook for summer rainfall. While the work completed to date has reduced the chance of floods like those of 2021, staff said, some of the interconnected elements of the various projects aren’t yet fully operational.

The Spruce Wash projects, intended to improve drainage and reduce flood risk in neighborhoods downstream from the 2019 Museum Fire burn scar, broke ground in 2023.

“We are pleasantly surprised, and also very gratified, that we are working well toward completing the final pieces of this puzzle,� Scott Overton, the city's public works director, told the council.

Noting the complexity of managing a watershed that routes through an urban environment, Overton added, “We’re hopeful that Mother Nature gives us one more break -- not so much for the fire side but on the flooding side. If we had one more nice, gentle, rainy monsoon season and we could get these across the finish line, that would be ideal.�

But Brian Klimowski, meteorologist-in-charge at the Flagstaff office of the National Weather Service, said, “We kinda think it’s perhaps gonna be on the other side of that coin� -- that is, a warmer, wetter monsoon.

Klimowski noted the historical correlation between a dry winter and a heavier monsoon. And with four of the last six monsoon seasons being relatively light, he added, recency bias might make this year’s monsoon feel even more intense if it delivers as much rain as expected.

“My message to you today is be prepared,� Klimowski said. Striking an optimistic note, he concluded, “The county and the city have done an incredible job with their mitigation. � I’ve worked with agencies across the country and what I’ve seen in Flagstaff is unprecedented.�

Councilwoman Khara House asked Klimowski if the reliability of weather prediction in Flagstaff and northern Arizona had been affected by federal budget cuts. “The tools we use haven’t been significantly impacted by any cuts,� Klimowski replied.

Julie Leid, co-owner of Flagstaff-based civil engineering and consulting firm Peak Engineering, then provided updates on the status of the individual Spruce Wash projects.

Some, like the reconstruction of Grandview Drive -- inverting the road’s previously raised central crown to channel water down the roadway instead of into yards and houses -- have been finished. Others, including the Wedge Detention Basin and the Cedar Avenue crossing culvert, remain under construction. (A complete list of individual projects is available at .)

Of note, Leid said that one of the temporary metal panels installed at the Linda Vista crossing to block water from entering the Wedge Detention Basin during its construction will be removed ahead of the onset of this year’s monsoon. Even if the basin is unfinished, “we would rather be cleaning up stormwater and floodwaters in our detention basin than cleaning it up in the front yards of people on Grandview,� Leid said.

Joe Loverich, project manager for JE Fuller Hydrology & Geomorphology, Inc., spoke to the council about the state of the burn scar recovery. He said he hikes to selected points each year to monitor vegetation regrowth, deadfall and soil conditions. While aspens are growing in some parts of the Museum Fire scar and there is, he said, slightly more ground cover now than in prior years, regrowth remains slow and patchy in the zones that burned hottest.

“We learn from every storm event about how the watershed is recovering,� Loverich said.

And data from both the upstream watershed and the downstream flood mitigation feeds into revised computer models of risk.

Though Loverich cautioned that those models are imperfect, because of the unpredictable dynamics of major storms, he said the latest modelling showed clear decreases to neighborhood flood exposure. “Just based on what’s been built, there’s huge benefits,� Loverich said. “The projects aren’t done yet, but it’s a whole lot better than it was� -- and should continue to improve as more projects reach completion.

The Spruce Wash suite of projects has cost approximately $40 million, with $26 million provided by Flagstaff’s Proposition 441 (approved by voters in 2022), $8 million coming from federal grants and $6 million supplied by the Coconino County Flood Control District. Additionally, the Flood Control District and U.S. Forest Service have completed about $16 million worth of forest restoration work upstream of flood-prone areas, bringing the total spent on local mitigation to about $56 million.

Leid noted that many of the projects have been also able to incorporate “added value� improvements, such as replacing sewer lines or waterlines, thanks to inter-departmental coordination and tapping into funding sources specific to those objectives.

Ed Schenk, director of the city’s stormwater section, highlighted some of the completed work done in the Schultz Creek area following the 2022 Pipeline Fire -- including the major floodwater detention basins between Schultz Pass Road and Elden Lookout Road, and downstream channel stabilization -- as well as the ongoing maintenance to the city’s stormwater infrastructure.

City and conservation corps crews have cleared over 4 miles of open channels this calendar year, Schenk said, removing 150 bags of litter and “countless� truckloads of slash and vegetation, including invasive species. Schenk praised the American Conservation Experience and Arizona Conservation Corps crewmembers for their efforts.

“It has taken some time to get some of that slash removed. � That’s just due to some of the uncertainty at the federal level with some of those AmeriCorps and conservation crews,� he acknowledged. “We had some stop-starts with some of them, and luckily that’s been resolved -- at least for now.�

Schenk also said improvements to the Fanning Wash channel, downstream from the burn scar of the 1977 Radio Fire, are in the design phase currently. Stormwater flowing off that burn scar led to the now-infamous 2021 viral video of a Toyota Prius floating downhill, he noted, emphasizing just how long the hydrological effects of wildfire can last.

Mayor Becky Daggett, recalling the stressful experience of monitoring rain gauges during previous heavy rainfall events, thanked all of the partners involved in the flood preparation and mitigation work.

“This has been one of the least stressful presentations, and I’m glad that we’re at a place where tensions aren’t so high and people’s property isn’t threatened in ways that it has been in the past,� Daggett said. “It’s nice to see how much work has gone into the problem, and just the coordination and the planning between all of the partners. It’s really phenomenal.�

“Water in designated channels is a beautiful thing,� she concluded.

Advice for residents

The presentations also included some suggestions for Flagstaff residents ahead of monsoon season.

Daniel Kelly, the city’s emergency manager, encouraged everyone to know their evacuation zones and evacuation routes ahead of any possible flood event.

Information about evacuation zones is available at .

Brady Henderson, the health and resilience coordinator with the city’s Sustainability Office, made a brief presentation about the city’s flood-proofing grants for homeowners and renters.

The grants provide up to $7,500 for flood gates, sealants or temporary barriers. Applications are processed on a rolling basis. More information is available at .

And Schenk, noting that most homeowner’s insurance does not cover flood damage, suggested purchasing or renewing flood insurance. Flagstaff residents can receive a 25% discount on insurance through the National Flood Insurance Program at .