Herriman • Hundreds of residents of Salt Lake County’s southwest corner launched a referendum campaign Wednesday in hopes of overturning county approval of the Olympia Hills development.

The campaign is taking shape a day after the County Council gave its final approval to a set of zoning changes allowing the high-density 933-acre development just west of Herriman to be built as a master-planned community.

“I’m just blown away that the council literally ignored six city mayors representing about 250,000 people and just did what they wanted to do," said Justin Swain, spokesman for Utah for Responsible Growth.

Swain said to the best of his knowledge, Salt Lake County is the only county in the entire state that is allowed to approve a land use development without cooperation from nearby cities.

Swain noted that the six council members who voted in favor of the Olympia Hills project live an average of 22 miles away from the property. “I think that makes it pretty clear why this should not be a county decision," said Swain.

“We presented data...we had numbers, we had all kinds of legitimate concerns based on empirical evidence that were largely ignored.”

Swain said there are two things citizens can do to make a change — taking a direct approach and addressing the underlying issue. He said Utah for Responsible Growth already took a direct approach by contacting the developer, and had a positive response.

Swain also urged citizens to address the systematic issue — leadership. “If leaders won’t do what’s best for us then we need to take action and we need to replace them with leaders who will.”

Riverton City Mayor Trent Staggs echoed the belief that the decision to implement the Olympia Hills project should be up to the city, not the county. “Most of those important decisions should be made at this level, at the community level. I think communities lead and politicians follow,” Staggs said.

He also made a surprise announcement that he is running for county mayor. He said his campaign will focus on the theme that he will be a leader that listens. Staggs will focus on three key areas, “smart responsible growth, empowering communities, and fiscal responsibility."

Development supporters on the county council said the project has been thoroughly studied and shaped by county planners. The county’s deal with developers Dough Young, John Gust and their partners also includes detailed rules for how they would build Olympia Hills over the next 25 years — and how they will pay their share of costs to mitigate impacts from the development, both inside and outside of its borders.

Plans for Olympia Hills call for up to 6,330 new single-family homes, townhomes and apartments and 1.8 million square feet of office and retail spaces to be built over 25 years in that unincorporated southwest portion of the county.

Olympia Hills would have a density of roughly 6.9 dwellings per acre, far higher than densities allowed by cities in their master plans for lands nearby, which range from three to five homes per acre.

For nearly two years, residents of Herriman, Bluffdale, Riverton and adjoining communities have gone to rallies and public meetings to voice their opposition to the project, which they fear will worsen traffic, overwhelm public schools and have other adverse effects on their quality of life.

The development is also opposed by mayors and other elected officials from those cities, many of whom say the county has ignored their concerns.

State law sets a high standard for referendum efforts. After applying for and securing county approval for a petition effort, opponents would have 45 days to gather signatures from 16% of Salt Lake County’s active voters, both countywide and within at least five of the county’s seven council districts. According to a state elections official, the number of active voters in the county stands at 541,555 — meaning opponents need to gather 86,648 valid signatures countywide to qualify for the ballot.

Tribune reporter Tony Semerad contributed to his report.

Correction: 11:00 a.m., March 5, 2020 — Under Utah law, proponents of a referendum initiative on land-use policy in Salt Lake County need to gather signatures from 16% of active voters, which would amount to 86,648 signatures. A prior version of this story misstated that percentage and signature total.