Miami residents trudge through knee-high flooded streets in rubber boots as water pours over a vulnerable seawall, an apocalyptic scene reminiscent of the hurricane that battered Florida two months ago.

But the footage isn’t part of a news report. It’s a campaign video, supporting a referendum Tuesday that would allow the city to sell $400 million of bonds to finance projects that protect against the impact of climate change. “We cannot control nature, but we can prepare the city so Miami can be forever,” Mayor Tomas Regalado, a Republican, says in the advertisement.

Not long after Hurricane Irma’s rains left parts of Miami submerged in brackish water — an event Regalado attributed to the Earth’s rising temperature — the vote will mark a test of whether residents in one of the most vulnerable U.S. cities are willing to get behind public works needed to safeguard homes and businesses from the potentially turbulent decades ahead.

In the Florida city of 454,000, the risks don’t feel so remote. Most homes sit only a few feet above sea level, and excessively high tides cause sunny-day flooding almost monthly. That’s made a late climate change convert of the two-term mayor, who is bucking the skepticism in much of his party to endorse the bond measure as one of his last initiatives before leaving office this year. He has demanded that Republicans do more to address its implications, even nudging President Donald Trump, who in the past dismissed global warming as a hoax.

“All areas of the city have some issue associated with either flooding, sea-level rise or some kind of water that we have to deal with,” Chris Rose, Miami’s budget director, said in an interview.

Climate Pioneers

Miami is following a small number of U.S. cities that have asked voters to back bond sales to cope with climate change. In 2012, Seattle voters overwhelmingly approved a $290 million debt measure to rebuild the Elliott Bay seawall that protects the downtown waterfront. In the San Francisco Bay area, residents last year approved a tax to fund a $500 million restoration of tidal marshes, which act as a buffer against storm surges.

The Miami bond vote is the fruit of a proposal that was fiercely debated among city commissioners before ultimately getting the go-ahead. It received backing by First Street Foundation, a Brooklyn-based nonprofit that advocates addressing the effects of rising sea levels.

Nearly $200 million of the general-obligation bonds would seek to mitigate rising sea levels and flooding, $100 million would finance affordable housing, and another $100 million would support parks, cultural facilities and road improvements. According to backers, the four inches of sea level rise in the past decade have already increased flooding by 400 percent in Miami. Some 2,000 homes are currently at risk from tidal flooding, while 5,000 face flooding risk from Category 1 hurricanes, the lowest grade.

Since the measure was placed on Miami’s ballot, the city got a vision of what the destructive power of rising seas could look like. When Hurricane Irma swept over Florida in early September, making landfall in the state as a Category 4 storm, the downtown business district saw the streets in front of its banks and luxury hotels turn into a raging river, even though Miami dodged the most dire predictions when the storm’s course shifted west.

The borrowing, if approved, would pave the way for Miami’s first sale of bonds for new construction projects since 2009. Fernando Casamayor, the finance director, said the initial bond sales could come as soon as next year.

Bellwether Vote

Other coastal communities considering similar measures will be watching to see if Miami voters want to pay to fight sea-level rise, according to Abby Corbett, a Miami lawyer who works with local officials around Florida.

“It’s a bellwether of popular support and understanding of this issue,” Corbett said of the ballot measure. “If it doesn’t pass, there’s definitely more education to be done.”

As the favorite in Tuesday’s mayoral balloting, City Commissioner Francis Suarez is most likely to oversee any flood-prevention program even though he voted against the bond referendum when the panel approved the initiative in a 3-to-2 vote in July. The commissioner wanted more information about how the money would be spent, but understands the need to deal with climate change and rising sea levels, said Gaby Castillo, Suarez’s campaign manager.

Suarez, who wasn’t available for an interview, has yet to say whether he will vote for the $400 million bond proposal on Tuesday, Castillo said.

Michelle Kaske and Jonathan Levin report for Bloomberg News.