The Save South Boulder group, along with three Boulder residents, filed a lawsuit against the city on Wednesday, challenging the legality of the Boulder City Council approving a $66 million bond to fund the South Boulder Creek Flood Mitigation project without bringing it to residents for a vote in an election.

“Arguably, the project’s $66 million price tag is the most expensive public works project ever undertaken in the city,” plaintiff and south Boulder resident Steven Telleen said in a release. “It benefits only a tiny fraction of the city’s structures, and it’s being pushed through without a vote of Boulder’s citizens, all of whom will bear its costs.”

Sarah Huntley, Boulder’s director of communication and engagement, said on Wednesday that city officials had not yet received notice of the litigation, so she could not comment on the complaint or claims of the lawsuit. Huntley said city officials will provide a response through public court filings at the appropriate time.

On March 6, the Boulder City Council approved the allocation of $66 million in bonds to fund the South Boulder Creek Flood Mitigation project. The South Boulder Creek Flood Mitigation project aims to minimize damage in a major flood event, protecting roughly 2,300 residents and 260 structures in the area, according to a city website.

The bond proceeds will pay for the land acquisition and construction of flood prevention infrastructure on and near the CU South site, according to a city website. CU South is a parcel of land owned by the University of Colorado Boulder that the university plans to develop in the future.The $66 million in bonds will be paid for through a city stormwater and flood management fee, according to the city ordinance. The lawsuit alleges that the increase in the stormwater fee through the ordinance is, in reality, a tax that the city is attempting to levy in violation of the Taxpayer Bill of Rights, or TABOR.

TABOR, a state amendment approved in 1992, limits the amount of revenue governments in Colorado can keep and spend, including how much it can raise taxes without voter approval. The lawsuit alleges that by using the stormwater fee to pay for the bonds, the city is essentially instituting a tax that was not approved by voters, as required by TABOR.

“We think that is not only undemocratic, but a violation of the TABOR law in the state of Colorado,” said Marki LeCompte, a plaintiff, Boulder resident and co-chair of Save South Boulder.

The ordinance, however, said that city representatives could issue revenue bonds payable from the fee without voter approval because the stormwater and flood management fee can be defined as an “enterprise” under TABOR. An enterprise, according to the Colorado General Assembly, is a government—owned business that receives revenue in return for the provision of a good or service. An enterprise can receive up to 10% of its annual revenue from state and local government sources combined. The lawsuit disputes the city’s claim that the stormwater and flood management utility is an enterprise.

Part of the South Boulder Creek Flood Mitigation project includes a 2,300-foot-long spillway, also known as a dam, that will direct detained water under U.S. 36 before returning it to South Boulder Creek. Part of what the bond ordinance will fund is the construction of the dam.

“The city acknowledges that the dam will appear 30 feet tall from some areas, and 18 feet tall from (U.S.) Highway 36, creating an eyesore that blocks our precious open space vistas,” plaintiff and south Boulder resident Harlin Savage said in a release.

LeCompte said other concerns with the dam include habitat and wildlife destruction, design flaws and destruction of open space.

Ultimately, LeCompte said, the real issue is based on the city bypassing procedures and using a method of paying for the project which is “questionably legal.” LeCompte said there has been little opportunity for the public to weigh in on the project and that the funding for it should have been put to a vote.

The lawsuit also alleges that city officials should not have passed the ordinance by emergency and that it was unnecessary. A standard ordinance involves at least two separate council meetings and is not effective until 30 days following council action. An emergency ordinance was enacted for the South Boulder Creek project to stay on schedule to begin the bid process in March.

“Most of the people who are going to be paying for this project will receive no benefit whatsoever from the dam because they live in north Boulder, they live everywhere else except south Boulder,” LeCompte said, adding, “We believe that the funding strategy that the city’s using is not legal. And that is why we are suing.”