The University of Minnesota is nearing the start of a 40-year process that will turn a huge swath of UMore Park in Rosemount into a new master-planned community.

Preparations will begin this summer for a massive gravel mining operation, which will eventually pay off when the proceeds are used to develop the land. The company doing the mining is ready to present its plans soon, after altering them in an attempt to appease nearby residents fretful about the impact of a gravel pit extracting more than a million tons of rock per year.

Getting power and mining equipment to the 1,250-acre site and setting up concrete and asphalt production could take about 12 months, so it will be 2013 before the first gravel products are trucked out, said Shawn Dahl, director of real estate and aggregate development for Ames Construction.

Ames and concrete producer Cemstone, in a partnership called Dakota Aggregates, are the winners of a 40-year gravel mining contract with the U.

The U decided in 2005 to sell the gravel to raise money to develop the land. Gravel deposits extend under a third of the 5,000 acres the university owns. The mining could bring the U $3 million to $5 million a year if construction demand for gravel is strong, said Charles Muscoplat, president of the UMore Development LLC.

The area to be mined is south of County Road 42 on the east side of Rosemount and extends south of County Road 46 into Empire Township.

To get started, Dakota Aggregates will need a city permit, which must be renewed annually. The proposed plans are expected to be subject to a public hearing soon.

In recent briefings, Dahl and Tim Becken, senior vice president of operations at Cemstone, told residents the company will make every effort to control dust and noise.

The north section of the mine -- closest to neighborhoods along County Road 42 -- will be kept at least 1,000 feet from homes. In that location, mining will last no longer than 15 years, they said.

To shield residents from the view and noise of the north mining area, topsoil will be scraped off the mining area and formed into a 10-foot-tall berm along County Road 42. As the mining progresses, the equipment will operate deep below the surface, further muffling the noise, Becken said.

Dakota Aggregates proposes to open 80 acres at a time for mining, then close it back up and re-cover it with topsoil before moving on to another 80.

The university will continue to farm 131 acres between County Road 42 and the mine, and that also could create dust and noise. As the mining moves south, more land will be returned to farming.

Dakota Aggregates also plans to locate its processing plant far away from larger neighborhoods, on 160 acres in the southeast corner of Rosemount, with primary access off County Road 46.

The noise of the washing and crushing of gravel at the plant will reach about 90 decibels. When heard at the distance of homes north of County Road 42, it is expected to sound like 65 decibels -- lower than the 76 generated by peak-hour traffic on 42, Dahl said,

The primary route used by trucks carrying gravel, concrete and asphalt will be east from the mine on 46 to Hwy. 52, Becken said.

There will be no nighttime hauling from the north mining area, and from the south area, trucks will go out at night only as needed to meet road and other construction demands, he said.

Mining shipments will add about 262 truck trips a day to County Road 42 and 538 on County Road 46, Becken said.

The south mining area, south of Boulder Trail, will start at the same time as the digging in the north and continue for 25 years. South of 46th Street in Empire Township, the mining will continue for another 15 years.

When the mining is finished, the area on either side of County Road 46 will be a lake 60 to 70 feet deep.

As phases of the mining conclude, the U plans to begin reshaping the land with buildings and houses.

"We think that we can help design a modern, sustainable, innovative community that will be a model for future development for things like modern schools, energy savings, mass transit and health care delivery," Muscoplat said. "It would be our plan to be at the leading edge of innovation."

Laurie Blake • 952-746-3287