"That's one thing I have against developers. They find a little square of ground and they have got to develop that, squeeze everybody in there," Mecham said.

Densities in Jordanelle run the gamut from one unit per 40 acres on sensitive land habitats to eight units per acre on prime sites, according to Al Mickelsen, Wasatch County planner.

Bonus densities are granted to developers offering affordable housing components.

You won't find those densities in unincorporated neighboring Heber Valley, where the highest density allowed is 1.3 units per acre.

McMullen contends water quality will worsen as more structures rise.

"They have rezoned so much land," she said. "The way the planning has been done nobody is looking at the big picture. Everything that has happened up on the hill is going to have dramatic effects to the valley."

But Dan Matthews, manager of the Jordanelle Special Service District, downplays such anxieties, saying that much of the growth will take more than 30 years to realize.

"(Besides) If you are a 'no growther,' one house is a bad idea," maintained Matthews, guessing that the area will likely only reach 6,000 units over a 30-year span.

Mike Ahlin, president of the Jordanelle Basin Owners Association, agrees. He praises the county's foresight in mapping out such a vast area comprising varied property owners despite "antiquated ordinances based on limited growth in the county."

"The county commissioners have done an exemplary job of planning the area," Ahlin said, adding that approximately a half million dollars of private money went into designing and laying out the area's first phase on the reservoir's west side.

Additionally, tens of thousands of dollars have been poured into plans for two other areas on the reservoir's east and south shores, taking into consideration everything from geologic hazards and wildlife habitat to wetlands and traffic.

"Other places don't go to the extent we have done," Mickelsen said.

Yet good planning wouldn't permit 13,000 homes in a watershed area where more than 350,000 Wasatch Front residents get their drinking water, according to Zach Frankel, executive director of the Utah Rivers Council, a nonprofit group dedicated to protecting Utah's rivers.

With 40 percent of Jordanelle's water reserved for Salt Lake residents, dire consequences to the Provo River watershed are in store, Frankel predicts.