2020 TF floodplain map

Changes to the floodplain in Three Forks are shown in this screen shot.

The Three Forks City Council this week took action to ensure a happy ending to a hypothetical tale of two cities — one facing the best of times and the other the worst of times for future economic development.

The narrative unfolded during Tuesday’s council meeting, where officials from the state Department of Natural Resources presented information indicating the floodplain maps being updated by the Federal Emergency Management Agency (FEMA) are likely to show that more land in and around the city lies in the floodplain than previously believed.

FEMA conducted a new hydrology study in the Jefferson and Madison river watersheds in 2018, and city officials have been waiting for maps based on that study to be released. Just this week, DNRC released preliminary data that FEMA will use to create its maps.

The data, including several interactive maps, can be accessed at floodplain.mt.gov/madison.

DNRC’s Nadene Wadsworth explained to the council that the new data predicts where water is likely to go during a 100-year flood, which is defined as the area that has a 1 percent of flooding in any given year.

“What we’re actually seeing is that during a 100-year flood event on the Jefferson, water is splitting off and going through the city limits and trying to make its way back to the Jefferson River,” she said. “The new study is showing there is a significant risk of flooding for the city.”

Council members did not welcome the news because of its implications for future construction and economic development in the city, as well as the requirement that will be placed on more residents and business owners to purchase flood insurance.

City officials historically have argued that the actual flood risk in Three Forks is minimal. The original Three Forks townsite was located north of the present-day city, but the town moved in 1908 “because it didn’t flood over here,” Mayor Sean Gifford said a year ago when interviewed by the Belgrade News.

It wasn’t until the 1980s that a floodplain map for the Three Forks area was adopted and development in the city became subject to regulations. That’s when FEMA began requiring people to purchase flood insurance if their properties were mortgaged, a rule that still exists today.

Even after 1980, Three Forks was able to opt out of the state requirement that structures be built 2 feet above base flood elevation, said Kelly Smith, the city’s floodplain officer. However, when FEMA adopted new maps for Three Forks in 2011, the city was forced to adhere to the rule. City officials say that has discouraged construction projects in town ever since.

The 2011 maps were based on hydrology studies done in the 1930s. City officials were hopeful that the hydrology study done a couple of years ago would confirm their belief that the flood risk in the city is non-existent, though they did worry that a new map might show just the opposite. That concern was confirmed for the council Tuesday night.

In anticipation of such an outcome, several agencies have been working together with the city to develop a mitigation strategy before the new FEMA maps are published. Engineers are already at work designing a project to mitigate a flood situation for the city when one occurs. Their work has been funded Headwaters Economics, a nonprofit agency that works to improve