Coconino County.
COCONINO COUNTY — The Coconino County Flood Control District (FCD) and the City of Flagstaff hosted a one-and-a-half-day Engineering Summit in the continued effort to identify long-term flood mitigation for the Museum Flood Area.
Representatives participated from the US Forest Service, Army Corps of Engineers, Flagstaff Unified School District, Arizona Department of Water Resources, the Federal Emergency Management Agency (FEMA), Arizona Geological Survey, Arizona Department of Transportation, and ten civil engineers from six private engineering consulting firms, as well as staff from both the County Flood Control District and City of Flagstaff.
The engineers heard about the history, challenges, and opportunities from FCD and City staff. They also discussed lessons learned from the Schultz Flood Area and held a workshop to facilitate brainstorming. Brainstorming was based in foundational principles of forest restoration, and an integrated approach of watershed restoration along with neighborhood conveyance, which has long-term benefits that increase through time as the watershed recovers.
“This is a tough message to deliver. With additional analysis, we will develop a targeted rainfall design storm goal. We’re probably down in the post-wildfire 5–10-year storm. We will not be able to design to every storm. It is not physically possible. It’s just not feasible. However, what we do will help reduce impacts during larger storms, but it won’t eliminate impacts, and that’s really important to understand,” said Deputy County Manager Lucinda Andreani.
A public report-out was held at noon today, where Lucinda Andreani, Coconino County Flood Control District Administrator, Joe Loverich, P.E. at JE Fuller Hydrology and Geomorphology, and Julie Leid, P.E. at Peak Engineering presented opportunities that include completing forest restoration work in the Spruce Avenue Watershed, enhancing alluvial fans for sediment reduction, implementing channel stabilization, and potentially upsizing the infrastructure throughout the city, all of which will be evaluated against a set of professional standards based upon the theory of “no adverse impacts.” The next phase of the work will be to complete a drainage master plan and conduct a study of the amount of sediment that is and will be produced out of the burned watershed and then to move into evaluating the feasibility of the potential projects identified at the summit. All projects must be technically, financially, legally, culturally, and environmentally feasible.
Simultaneously the District and City must pursue federal, state, and local funding sources given the cost of flood mitigation will likely be in the tens of millions of dollars. Andreani closed out by saying, “A key priority for both the District and the City must remain forest restoration, particularly on the western slopes of the San Francisco Peaks, which is the Upper Rio de Flag Watershed. Given the size of that watershed we know the downstream flooding impacts through the Fort Valley, Cheshire and downtown Flagstaff would be horrific.”
To watch a recording of the Engineering Summit Report-Out, visit: https://www.youtube.com/watch?v=y7nvE9S0Dgs&t=9s
The FCD and City recognize that monsoon season is not over, rather, it lasts officially until September 30. Residents of the Museum Flood Area should maintain their mitigation, have a stay-kit prepared, and a communications plan with family. For more information and updates, please visit https://coconino.az.gov/2133/Museum-Fire-Flood-Area