The 7-1 Salt Lake County Council vote to approve a planned community development of some 8,800 housing units on a 931-acre parcel earlier this week may not have been as decisive as it seemed.

A massive pushback from city leaders and thousands of residents in the southwest part of the county prompted county Mayor Ben McAdams to hit the pause button.

He asked for postponement of final approval of the development agreement that had been scheduled next week before the Municipal Services District board — a delay confirmed Friday by Bart Barker, district general manager.

The extra time, McAdams wrote late Thursday to the board, could provide “an opportunity to respond to residents’ concerns by considering alternatives that may result in a plan that addresses not only the needs of residents represented by the MSD but also the concerns expressed by the residents in neighboring cities.”

On Friday morning, McAdams tweeted out thanks to all the residents providing feedback. “I am listening,” he assured, adding that his move for postponement was so that “all sides can consider alternatives.”

McAdams’ interest in exploring a compromise comes in the wake of a grass-roots wave of opposition that lit up the mayor’s phones Thursday.

The mayor released a joint statement from himself and the County Council during a Friday evening news conference, saying they had reached out to elected leaders in Herriman, Riverton and South Jordan and West Jordan and are working to address residents’ concerns.

Organizing through social media, residents of Herriman, Riverton, West Jordan and surrounding communities pushed the mayor to veto the council’s vote.

“We’ve been getting a lot of phone calls,” Michelle Schmitt, a spokeswoman for McAdams, said Thursday.

An online petition launched midday Thursday had swelled to some 6,700 signatures and counting by Friday evening.

This resident pushback came in the wake of a joint statement of opposition by Mayors Trent Staggs of Riverton, David Watts of Herriman, Jim Riding of West Jordan and Sean Clayton of Copperton Township.

“The sheer number of units in the development is nothing short of overwhelming,” they wrote.

This is a comparison chart that was distributed by southwest Salt Lake County mayors, who argue that the proposed development threatens to overwhelm the area.

The project calls for 4,783 apartments, 2,485 town houses and 1,497 single-family homes on quarter-acre lots in the area between 6300 West and 8500 West and 12400 South to 13100 South. The proposal envisions up to 500,000 square feet of retail and office space and a 100-acre Utah State University campus, around which the densest apartment-style housing would be clustered.

“It is estimated that this would add an additional 30,000-plus residents to the southwest part of the valley; essentially adding another city approaching the size of Herriman or Riverton, but in a tenth of the land area,” the mayors wrote.

McAdams has been aligned with other elected leaders — including state House Speaker Greg Hughes, R-Draper, and Gov. Gary Herbert — calling for the state and Salt Lake County to deal with the coming population explosion with high-density planned communities built around transit.

Given that view, would the mayor seriously consider a veto of Olympia, which appears to follow the model these leaders have endorsed?

McAdams said at the Friday news conference that a veto was an option, but that he thought a better result could be achieved by compromising with stakeholders.

His spokeswoman also noted that the council approved the project with a supermajority. That means if the council members stuck to their guns, they could override a mayoral veto. McAdams has until June 20 to veto the vote.

The mayor told reporters Friday that he understands residents’ concerns about density, but that at the core the issue is about housing choices and striking the right balance between single-family homes and other housing types. McAdams believes he can do that without a veto.

“Right now, I think we could get a better outcome by sitting down with the parties, the mayors and County Council and developers and asking for some concessions,” he said, “and try to find that win-win so we can move forward with a proposal that will be acceptable to everyone.”

McAdams is running for Congress in the 4th District, which includes the area where residents are expressing their outrage. That seat is now occupied by Rep. Mia Love, R-Utah, and polling indicates the contest is tight.

Leaders in Herriman City, where much of the fiercest opposition is centered, are encouraged by the signs of compromise.

“We want to work together, we want to create smart developments, developments that benefit the communities that they’re in while limiting burdens,” said Herriman spokeswoman Tami Moody. “Our roads are the roads that are going to be impacted, our schools, our water.”

She said Herriman’s goal would be “maybe being able to simplify this project more and negotiate its size.”

“We can’t say if they’re willing to come down in their number of units or not, but it definitely warrants some discussion and it does appear that they’re willing to talk to us, and that’s always a good sign.”

The online petition attempting to marshal opposition lists the office phone and email of McAdams and all council members except Steve DeBry, the lone dissenting vote. (It also lists contacts for Council Chairwoman Aimee Winder Newton, who was absent for the vote.)

The petition was started midday Thursday by Justin Swain, who recently built a home in Herriman, he wrote, for the relative quiet.

He blamed the “recent rogue decision” by the county in approving this “absurd” plan and blowing up expectations for the kind of low-key, single-family community he and his family sought.

“The majority of the council members that made this decision DO NOT live in communities that will be affected by the rezoning and thus DO NOT have our best interest in mind,” he wrote. “A handful of individuals have decided that they know better than the tens of thousands of community residents and city mayors they are supposed to represent. This is unacceptable and we should not stand for it.”

Reporter Paighten Harkins contributed to this story.