"It's a big deal," said Council Chairman Charlie Luke.
The shortfall comes 18 months after the council hiked meter rates from $1.50 to $2 an hour and increased enforcement hours from 8 a.m. to 8 p.m. The previous time frame was 8 a.m. to 6 p.m., and Saturday curb-side parking remains free but a two-hour limit was imposed.
According to projections from the administration of Mayor Ralph Becker in 2012, those actions should have raised parking revenue by about $1 million per year.
At the same time, the city urged motorists to make use of an estimated 30,000 public parking spaces downtown in privately owned garages and surface lots.
Luke wonders why revenues are down. Is it motorists using private lots? Is it more people using TRAX? Is it people staying away from downtown due to the parking rate hike? Is it fewer parking tickets?
"That's what we're trying to figure out," he said.
Luke voted against the parking-fee hike 2012, saying it could keep people from coming downtown for shopping, dining and entertainment. He noted that a number of Salt Lake Valley malls offer free parking.
In an interview this week, Luke said he hopes he was wrong.
"When you are talking about economic development, you're talking about bringing people downtown," he said. "I had argued a rate hike would discourage people."
Councilman Kyle LaMalfa agreed that the $1.5 million shortfall is significant.
It throws a wrench into the city's $221 million budget, he said. "We are going to have to make some cuts somewhere to make up for it," he said.
Although there is no evidence, LaMalfa said part of the phenomenon may well be motorists seeking parking in private facilities.
"There may be some good news in this," he said. "Part of the reason we raised rates was to get people to use private parking garages."
Businesses sought the evening enforcement extension from 6 p.m. to 8 p.m. in order to increase turnover at curb-side slots. According to Jason Mathis, of the Downtown Alliance business group, increased turnover helps retailers, particularly restaurants that don't want employees taking up what could be customer parking in front of their eateries.
Becker spokesman Art Raymond said city analysts are "crunching numbers" to determine what caused the shortfall.