Instead of doing that, they decided instead to put the money into new facilities.
"Building the north concourse sooner, rather than later, is the best solution for the future," said Maureen Riley, director of the city's Department of Airports.
Salt Lake City Mayor Jackie Biskupski announced the decision.
"This addition is essential in building a state-of-the-art facility to help attract more business and tourism dollars, and completely in line with my plan for robust economic development," she said.
The airport said all airlines operating there unanimously approved plans to build the second concourse now. The airport currently serves about 22 million passengers annually, more than twice its design capacity.
Construction on what is called the Terminal Redevelopment Plan has been ongoing for a couple of years already, but mostly in areas not seen by passengers including relocating car-rental maintenance facilities and utilities. Construction is about to shift into a higher gear, and some roads will be relocated this month.
Plans had always called for opening a new terminal building plus the new south concourse beginning in 2020, with 45 gates. Now, a parallel, 30-gate portion of the north concourse is also planned in two phases, and also projected to be finished in 2020.
The two concourses will be connected by a tunnel. Their parallel design avoids problems with current spider-arm layouts that sometimes lead aircraft to block neighboring gates as they back out, arrive or wait, and limit operations.
The north concourse eventually may be expanded to add another 15 gates depending on demand.
The north concourse will replace existing gates now on Concourses B, C and D, which the airport said have significant deficiencies that would require costly renovations to keep in use for a few more years as had been planned.
It also said those renovations would significantly disrupt airline operations and require multiple relocations by each airline.
The airport said that adding the new south concourse will provide better customer service than retaining the older concourses.
"Every step our airport takes in the redevelopment effort is an exciting one," said City Council Chairman James Rogers. "The end goal is an airport that better serves customers, and is an even bigger economic driver for growing the northwest quadrant of our city and all of the Utah economy."
Biskupski said, "We are on track to making the entire [airport] experience more efficient and pleasant for everyone."