Picture a Utah with nearly 7 million residents, crowded schools and mind-numbing traffic jams. It's not too hard to see from here for most Utahns, who rate population growth and its attendant headaches a Top-10 issue.

The Utah Foundation released a research brief Thursday based on a January survey by Dan Jones and Associates in which 52 percent of respondents said the state is growing too quickly. The 2.6 million who live here now will see their numbers swell to 6.8 million or beyond by 2060, the foundation projects.

Think it's crowded now?

Utah is a growth leader that shows no signs of slowing. The population is expected to eclipse 4.5 million in about two decades, a little smaller than present-day Colorado but bigger than today's Oregon.

By 2060, it could reach 6.84 million - bigger than either Arizona or Washington state today. Among other challenges, that surge will put a squeeze on Utah's water supply, one of four growth-related issues that Utahns graded 4 or higher as a concern on a 1-to-5 scale. (The other three were traffic, school crowding and crime.)

Between a Lake Powell pipeline in the south and a Bear River diversion in the north, the state's water-development tab will exceed $1 billion in coming decades, according the Utah Foundation.

Southern Utah could experience acute water shortages as early as 2012, thanks largely to growth around St. George. Construction of a pipeline isn't expected to start until 2015.

A mess of our own making

Utah's growth issues have been, and likely will be, mostly due to its high birth rate.

What's driving traffic?

In sheer numbers, the big urban centers like the Salt Lake Valley and the Provo area keep adding the most. But smaller outlying cities are starting to stack up as serious bedroom communities that will steer transportation expenditures.

Saratoga Springs, on the west side of Utah Lake, was the percentage growth leader at 37 percent from 2000 to 2007, and Herriman and Eagle Mountain followed, each increasing around 30 percent.

Of the top 10 for growth, only Lehi had a population higher than 25,000. It all adds up to crowded streets - and costly upgrades - far from established freeways.

"It's always difficult to expand the transportation infrastructure fast enough to accommodate that kind of growth," Utah Foundation President Stephen Kroes said.

The foundation isn't recommending specific actions, although Kroes said he would not advise that cities impose housing restrictions that could balloon prices.

Who's responsible?

Most years, Utah's nation-leading births outpace its migrants, but last year was a rare exception, when migrants slightly edged natural increases, according to the foundation report.

That likely will reverse now that the economy is slowing, but Utahns appear much more worried about newcomers than they are about babies. When asked if they were more concerned about migration or the birthrate, 67 percent named migration, 7 percent said births and 13 percent listed both.

"They don't want people telling them how many kids to have," Utah Foundation President Stephen Kroes said.

While immigration is another top issue (it surpassed growth's No. 10 rank at No. 5 among respondents), most said they were only moderately concerned about social or cultural changes coming from an influx of outsiders (averaging a little over 3 on the 1-5 scale). Traffic was a bigger worry.

Who's in school?

By a large margin - 73 percent of the growth in enrollments last year - Utahns are breeding their own classroom-crowding issue. Tooele School District led the way with 5.6 percent growth between 2004 and 2007, the Utah Foundation found.

Statewide, the numbers are expected to spurt from barely 500,000 to nearly 700,000 by 2015. Meanwhile, higher-education enrollment already has more than doubled in the past 20 years. Won't crime grow, too?

Statistics disprove the theory that Utah's crime rate is ramping up with its population. Though major cities experienced crime spikes last year, the long-term trend is downward. Between 2000 and 2006,

Utah had only the 29th-fastest-growing prison population at the same time that it was the third-fastest-growing state.

Still, in real numbers, a larger population naturally will lead to more crimes even if the rate per 100,000 people goes down. "Even lower rates," Utah Foundation President Stephen Kroes said, "can mean more crimes around you."