Anticipating the Flood Next Time: Building Community Resilience for a 1964-Scale Scenario.

The objective of the flood preparedness project is to expand public awareness about the growing risk of severe storms and potential impacts – and risk mitigation measures – in the scenario of a 1964-scale flood. While local and state agencies have conducted disaster planning for a FEMA-defined 100-year flood, or a flood with a 1% chance of happening every year, little has been done to envision or prepare for the possibility of a much-larger flood event on the scale of the 1894 or 1964 Flathead floods. We will work with local governments to reduce home insurance premiums under FEMA’s flood preparedness incentive program, the Community Rating System or CRS. We’ll prioritize flood-prone areas for open space conservation, removal of toxic chemicals from the floodplain, education and outreach, and provide practical assistance to homeowners to reduce flood exposure.

Where it all started/Background

In Fall 2025, CSG launched this project to improve flood preparedness while cutting the escalating cost of flood insurance for residents and businesses in Flathead County. CSG initiated this project after witnessing the 2022 Yellowstone floods devastate homes, roads and communities.

Columbia Falls, Hwy 2 bridge/Teakettle fishing access site, 1964 Flood

The Flathead is not a stranger to mega floods, with the most dramatic occurring in 1964. In June 1964, roiling waters roared through the canyon and into the Flathead valley, hurtling houses, cattle, trees, bridges and boulders toward Flathead Lake, On the east side of the Continental Divide, at least 31 people died, primarily Blackfeet tribal members, when the Swift and Two Medicine dams collapsed under the onslaught of torrential rains upon a lingering mountain snowpack.

The scale of the 1964 flood is considered to have a recurrence interval between 500 and 1000 years. In reality, the so-called flood return interval is a statistical estimate. So-called 100-year floods have historically happened more frequently in the Flathead. And looking ahead, climate scientists confirm what most Americans are observing with their own eyes. Globally, massive floods are happening more often. What might have been considered a 100-year flood a few decades ago will likely happen more often in the coming decades.

But whatever its statistical validity, the 100-year benchmark remains highly relevant to daily lives. That’s because floodplain regulations adopted by local governments under the direction of the Federal Emergency Management Agency (FEMA) revolve around the 1% chance, or a 100 year flood, of a large flood in any given year.

The Western Montana Hazard Mitigation Plan, adopted in Spring 2025 by the county and cities of the Flathead, shows that 10% of Flathead residents, or 11,481 people, live within the 100-year floodplain. A flood of that magnitude would cause $383 million in damages and damage 136 critical facilities that provide essential energy, transportation and health services.

And what would be the impact of a 1964-scale deluge today? No one knows. That’s why this project seeks to map the impact zone and evaluate who and what would be affected.

Unfortunately, that assessment may remain elusive. While CSG has received some funding support from the Whitefish Community Foundation and the interagency Western Montana Conservation Commission, we are seeking new sources to replace a $75,000 federal grant to CSG that was terminated by the Trump Administration. No specific reason was given for the termination of EPA’s Thriving Communities program.

While we hope to complete some level of impact assessment and engage local communities to develop flood mitigation strategies, our scaled-back project is slated to focus more narrowly on increasing public awareness about the shifting risks. A particular goal is to expand Flathead County’s participation in FEMA’s Community Rating System, which incentivizes local governments to go beyond the bare minimum requirements for floodplain management which results in reducing flood insurance premiums for residents and businesses.

Flathead County is one of 10 Montana communities that participate in CRS, although currently at the lowest level providing for a 5% discount. Other Montana communities receive discounts of 15-20%. We also seek to enroll the cities of Kalispell, Columbia Falls and Whitefish in the CRS program, thus improving housing affordability by taking a bite out of insurance costs.

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2025 Accomplishments

  • “One in 500” Film screening & panel discussion
  • Convened GIS working group to develop on-line interactive map on flood risks
  • Research FEMA CRS program and submitted MOU to Flathead County to partner on CRS activities
  • Provided public comment on Whitefish, Kalispell, and Columbia Falls “Land Use/Growth Plan” regarding flood risks
  • Presentations to Rotary and other groups on program

2026 Projects

  • Create on-line interactive map on flood risks
  • Continue to pursue MOU with Flathead County
  • Provide public comment to Kalispell, Whitefish, & Columbia Falls regarding flood risks and CRS program
  • Public outreach on flood preparedness (Community events, webinars, presentations, press coverage …)
    Hazardous waste clean-up – pilot project

 

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