Eighteen years ago, an El Niño event wreaked weather-related havoc across the globe ranging from mudslides in California to drought-fueled wildfires in Australia. This year’s winter is forecasted to host a recurrence of that phenomenon, which could rival the intensity of the record 1997 event.
Navajo County Emergency Management has begun preparing for the potential county impact that could lie just ahead, including possible issues with the Winslow Levee, hosting a Winslow Levee Tabletop Exercise in Holbrook this week.
County administrating officials representing departments including Public Works Flood Control, Sheriff’s Office, County Management and Public Health Emergency Preparedness, along with officials from the Winslow Police Department, the City of Winslow, the Winslow City Council, the Arizona Department of Transportation, Little Colorado Medical Center and Northland Pioneer College, convened Oct 6 with a focus on establishing operational coordination among the local emergency management entities.
Assistant County Public Works Director and engineer Bill Bess joined County Emergency Management Director Mary Springer and County Emergency Management Coordinator Catrina Jenkins in explaining the purpose of the discussion. “Part of our preparedness for the failure of the Winslow Levee involves a critical facilities plan. We have 30 or so rain gauges throughout Navajo, Coconino and Apache counties that help monitor our drainage basin that eventually flows through Winslow. We use this information to help predict the water level depth and projected flow (of the Little Colorado River),” he said.
“One of the things we’ve done as part of our feasibility study (for flood risk management on the levee) is to identify critical facilities within the city of Winslow, including schools, the police station, fire station and hospital. Based on a 100-year event, until the levee is reconstructed and recertified by the Army Corps of Engineers, these areas are projected to be inundated. Winslow would have a lot of water downtown.”
The Federal Emergency Management Agency (FEMA) prepares a flood insurance study that analyzes the flood hazards in a community as the basis for floodplain management, mitigation and insurance activities in the National Flood Insurance program, explaining the probability and recurrence intervals for floods, and how a 100-year or other rare flood can occur more than once over a short time period.
Statistics from the National Oceanic and Atmospheric Administration reveal the sustained rains that, within three days, brought over two feet of water and catastrophic flooding to the Carolinas last weekend well surpassed an event that, on average, would be expected to occur about every 1,000 years. The storm’s rainfall totaled roughly 11 trillion gallons, according to data gathered by WeatherBell meteorologist Ryan Maue.
The county’s emergency action plan for the levee outlines that warning statements and response phases would initiate once river elevations reach the following stages:
* 17 feet, bank full, continuous monitoring.
* 19 feet, flood watch, mobilize equipment to the levee area.
* 23 feet, moderate flood, mobilize flood fighting emergency teams on standby.
* 25 feet, major flood, evacuate area behind levee and maintain flood fighting emergency teams.
Regarding the levee’s current reconstruction plan, Assistant County Manager Homero Vela explained, “The levee was completed in 1989. It was certified to meet 100-year protection. It failed twice after 1989, so FEMA decertified the levee. When FEMA decertifies a levee, they assume the levee does not exist there for purposes of a flood map. But the levee is still there and it offers protection for a 50-year, maybe even a 100-year event. The problem is that it’s not certified by FEMA, so (residents) have to buy flood insurance as if they were (located) in a flood plain. If the levee were certified, the flood plain map would not show the flood plain going into the city of Winslow, it would stop at the edge of the levee.”
Vela continued, “We’re not demolishing the northern extent of the Winslow levee. It stays intact and we’re going to keep maintaining it. We’re going to put a plan in place as soon as we have a design construction agreement with the Army Corps. The idea is to start thinking about what we are going to do with the rest of the levee. It could very well be that we will just add additional elevation to the levee and get it certified so that it functions as a 100-year protection. Our goal is to take care of the entire levee, we’re just doing it in phases.”
County officials say the Winslow levee feasibility study is scheduled to be completed in June 2016, with congressional approval of construction documents expected to follow by 2020 and reconstruction of the levee to begin in 2025.
Participants in Tuesday’s exercise found the dialogue productive in developing a more educated and responsive approach to mitigating a worst-case weather scenario this winter.
