Post / Glenn Asakawa Longs Peak looms behind a condo complex being built in Erie. The Denver Regional Council of Governments has put together a 25-year growth plan but put off discussing the runaway growth of the large-lot real estate market in Colorado.

For Thornton Mayor Noel Busck, it's almost as if people are coming up out of the ground.

The waves of them streaming through the Interstate25 corridor from the north mystify him.

"We act like growth is not happening," Busck said. "We're not even paying attention to it."

The growth of the exurbs - rural areas attractive to home buyers looking for large lots - is one of the biggest challenges facing Colorado planners. Experts warn that at the current rate of growth, exurban sprawl could consume hundreds of square miles of rural land along the Front Range in the next 25 years.

But the board of directors at the Denver Regional Council of Governments - the key group of planners charged with keeping growth sane in the region - plans to pass on the issue of how to control this hot new real-estate market for at least another year.

The United Nations-like assemblage of governments, made up of 42 towns and cities and nine counties, is on the verge of adopting a 25-year master plan meant to control sprawl along the Front Range.

The Metro Vision 2030 plan holds firm to a 750-square-mile boundary that would confine urban growth in the DRCOG counties - Denver, Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Douglas, Gilpin and Jefferson.

DRCOG (pronounced "Dr. Cog") defines an urban area as containing at least two houses per acre.

But the 2030 plan fails to contain growth of large-lot development - homes on an acre or more, such as ranchettes.

DRCOG's delay arises from a division between cities, which want to restrain exurban growth, and counties, which tend to support it because of the tax revenue it brings.

The organization's board will hold a public meeting tonight to hear suggestions before it formally adopts the measures in January.

Its officials say they will form an ad hoc committee next year to study policy options for semi-urban and exurban growth.

And while some say further study is only prudent, others on the board openly question the delay.

"Essentially, we're adopting this plan, but there are these very, very important issues that go to the heart of the plan that aren't going to be resolved until next year," Happy Haynes, Denver's representative on the DRCOG board, told colleagues last week.

Meanwhile the growth of the large-lot real-estate market has become a "runaway issue in Colorado," says Rick McClintock, director of the Livable Communities Support Center.

"It's good news that (DRCOG) said, 'Let's keep the growth boundary at 750-square miles," McClintock said. "That's a very strong symbolic goal. But the boundary ... doesn't achieve the goal of limiting sprawl."

In fact, DRCOG's board accepted a report from its staff in January 2002 that urged action on exurban growth.

The DRCOG committee found that, outside the roughly 500-square-mile urban footprint currently surrounding Denver, another 800 square miles of land already has been developed in semi-urban and exurban patterns. The committee projected that by 2020, large-lot developments would account for more than 1,200 square miles of the region's land.

Geographers at the University of Colorado at Boulder also forecast excessive exurban growth throughout the Front Range.

"The committee believes that this development pattern should be addressed in the Metro Vision plan even while research continues on the costs and benefits of such low-density patterns," the report says. "An unintended consequence of the Urban Growth Boundary has been the stimulation of additional semi-urban development."

But there is division on the board. And, because it is a volunteer effort, DRCOG as a decision-making body is only as effective as the consensus of all those 51 member governments.

The division springs from concerns about the bottom line.

"Cities live on sales tax. Counties live on property tax," said Larry Pace, an Adams County commissioner and member of the DRCOG board.

Cities tend to fear exurban growth because they believe exurbanites strain their infrastructure, Pace says. But counties, which reap the benefits of the large-lot property taxes, are less likely to try to curb their development.

Pace shrugs off the dilemma.

"The individuals who do live out there do go into the metropolitan area," he said. "And they provide sales tax, which tends to support those metropolitan areas. So there's that play-off."

Pace's economics are in dispute, however.

Environmentalists say the costs that far-flung large-lot communities place on the urban footprint quickly soar into the billions, in terms of traffic congestion, pollution and the strain on underground water supplies.

The split of viewpoints makes it hard for the 51 directors to come to agreement, said DRCOG chairman Lorraine Anderson, an Arvada city councilwoman.

"That's why we came to the conclusion when we first did Metro Vision that it had Staff writer Chuck Plunkett can be reached at 303-820-1333 or cplunkett@denverpost.com .