A family development team has unveiled plans for a 3,120-acre mixed-use development near Chatfield State Park in northwest Douglas County that eventually could include 10,000 to 12,000 homes.

The Sterling Ranch development, west of South Santa Fe Drive and Titan Road, is the largest undeveloped parcel left in northwest Douglas County.

The developers say their goal is to develop the land into one of most frugal water-use communities in the U.S.

"Starting with a blank sheet and using proven water-saving technology, we will use less than half the amount of water typical for a development of this size," said Harold Smethills, who is investing in the project with his wife, Diane, and former housing executive Jack Hoagland.

Hoagland, a former executive at Richmond American Homes and Carma Colorado, is the younger brother of Diane Smethills, who has 35 years of marketing, real estate development and finance experience.

Harold Smethills was a former top executive at Adolph Coors Co., the former president of Coors spinoff ACX Technologies and most recently the CEO of Menasha Corp., a giant packaging company based in Wisconsin.

The three investors also are proponents of proposed Colorado legislation that would allow the capture and harvesting of rain water, which would further decrease the use of water at Sterling Ranch.

Sterling Ranch is anticipated to have a total "economic and fiscal" impact of $435.4 million annually, including $11.2 million in estimated retail sales and property tax revenues, according to economist Patty Silverstein, principal of Development Research Partners.

The infrastructure costs over the next decade are expected to be between $3 billion and $4 billion, creating construction, engineering and infrastructure jobs.

When completed, the development would include 1,120 acres for residential neighborhoods, 1,100 acres of open space and parks, 74 acres of commercial property, 150 acres for educational uses and an 82-acre sports village.

One thing it will not have is a golf course.

"They use too much water, and Douglas County is sufficiently golfed," Smethill said.

The Smethills and Hoagland have been quietly putting the deal together for the past eight years.

They bought the 2,200-acre Sterling Ranch from Joy Burns.

The land has had only three owners since the Sterling family started the ranch in 1866.

The developers also are acquiring 640 acres of adjacent land from the State Land Board and the adjoining 280-acre Allis Ranch.

The housing at Sterling Ranch primarily will be focused on the "first and last" housing market: young professionals buying a first home, as well as active seniors selling their bigger homes for patio-style houses, Smethills said.

There also will be some executive and horse properties.

The team will sell lots to builders, but they are in no hurry.

"We're investors," Smethills said. "Our job is to envision the process, get utilities, establish the theme and bring in the home builders."

He said they would be ready to start building in 2010 or 2011, but they are going to let the market dictate when they begin.

"We are a family business, so we are not accountable to shareholders or Wall Street," he said

"We will let the market pull us in. The last thing we want to do is try to force something on the market that it isn't ready for it.

"We're very cautious folks."