Meanwhile, the Utah Supreme Court is expected today to rule whether a citizens' petition to hold a referendum on the same development will ever make it to the ballot.

Scott Peterson, a plaintiff in the new suit, lives in a neighborhood abutting the project. He worries Hamilton Land Co.'s 800 medium- and high-density housing units, and a 100-acre commercial center that includes Wal-Mart, would create traffic and safety concerns.

"We didn't feel like this part of the development is well-thought out," he says.

According to Riverton's general plan, all new residential developments greater than 40 acres are required to meet a 20 percent open-space standard regardless of density.

"We take that literally," says James Tracy, attorney for the plaintiffs. "We want the city to comply with its own laws."

Developers have proposed a 30-acre park west of Bangerter Highway. But residents say that hardly benefits families concentrated along the heart of the project near 13400 South and 2700 West.

"You have a safety concern with shuttling the kids," Peterson says.

Some longtime residents also worry the new housing - and the zoning to allow it - puts a pinch on existing horse property.

"It eliminates the ability to have horses," Tracy adds.

Riverton's City Council approved the final plat for the development July 30. Plaintiffs, who filed this week to make the 30-day deadline, were unaware of the complaint pending in the Supreme Court. That ruling could render the District Court cases moot.

djensen@sltrib.com