Salt Lake City's population is shrinking again — a fact that is solidifying the City Council's desire to spur massive development that would put some 25,000 new residents eight to 10 miles west of downtown.

Those plans, however, are giving pause to champions of urban growth like Mayor Rocky Anderson's office and environmental groups like the Sierra Club.

Almost across the board, City Council members say that developing homes in the city's northwest quadrant — north of I-80 roughly fixed between 6400 and 8800 West — will be key to expanding the city's population base.

"We do have to look at areas of the city where we can build whole, new neighborhoods, and one area would be the northwest quadrant," Councilwoman Jill Remington Love said.

There are four or five major property owners — including The Church of Jesus Christ of Latter-day Saints — of the roughly 3,000 acres of undeveloped land in the area, which is currently zoned agricultural and manufacturing.

That zoning is expected to change once the city completes its Northwest Quadrant Master Plan — a plan the City Council funded this year. The plan should open the area up for what Council members hope will be a new master-planned community, allowing Salt Lake City to compete with suburban cities for new residents and young families.

"I want to see it developed correctly," Council member Carlton Christensen said. "It will probably be developed one way or another, but I would like to see us truly have a master-planned community."

But the move may not be welcomed by everyone in Salt Lake City, where many residents have championed urban growth and less suburban sprawl. Some, including Anderson's administration, have called for greater urban density and less outlying development.

Northwest quadrant housing would be 60 to 80 blocks from downtown and Anderson's spokeswoman Deeda Seed maintains the development shouldn't take place there until a light-rail spur is built to the Salt Lake City International Airport.

"If we don't have a transit connection, we're going to be creating suburban sprawl," Seed said. "It's going to be a little pocket of unconnected people out there in the middle of nowhere, and that makes no sense from our perspective of urban planning."

A light-rail spur to the airport, however, isn't likely until at least 2015, according to plans from the Wasatch Front Regional Council. And even that spur would still stop several miles east of the northwest quadrant.

City Council members have a much faster timetable for development than 2015.

Lynn De Freitas, executive director of Friends of Great Salt Lake, along with Marc Heileson, regional representative of the Sierra Club, say they are keeping a close eye on development plans in the quadrant, which includes wetlands and flood plain.