DENVER – Colorado voters will decide in November whether to bump the minimum wage from $8.31 to $9.30 an hour in 2017 and to $12 an hour by 2020.

A coalition of groups have poured $1 million into putting the proposed change to the Colorado Constitution on the ballot and Colorado Families for a Fair Wage learned Thursday that it had turned in enough valid signatures to put the question to voters. On the ballot it’s likely to be Amendment 70.

“All the studies show that when working people have more money in their pockets they spend it,” said Patty Kupfer, with the Fair Wage campaign. “They spend it here in Colorado. That creates jobs and helps our communities thrive. It’s just about paying more to workers and that’s the end of the story.”

The proposed amendment will likely face a great deal of opposition.

Tyler Sandberg is heading up the Keep Colorado Working issue committee that launched in July and has raised about $113,000 to oppose the amendment.

“We’re having a great response from those concerned about the ramifications this will have on small business,” Sandberg said. “Study after study show that when you get minimum wage raises that go so far, you have exponential damage.”

The groups will likely raise and spend a lot of money making their case to Colorado voters.

As of Aug. 1 Fair Wage had $80,000 in its account after spending $1.1 million, primarily on a firm that pays people to gather signatures.

Fair Wage turned in 200,000 signatures to the Secretary of State’s Office and it’s highly likely that at least 98,492 are from registered Colorado voters – the miminum required to place an issue on the ballot. The office will verify a random sample of 5 percent of the signatures turned in and if enough of those are valid, the petition will be approved.

Much of the money raised by Fair Wage came from national nonprofit “social welfare” groups committed to issues like increasing the minimum wage. The second largest donors were Colorado labor groups.

Kupfer said the last time voters approved an increase to the minimum wage was in 2006 when it was set at just under $7. The minimum wage has increased using a formula tied to the Colorado Consumer Price Index and is at $8.31 today.

Amendment 70 would raise it immediately by $1 and then by 90 cents a year after that until 2020. After 2020, the minimum wage would go back to increasing with the CPI.

“We feel like it’s really a modest approach and takes their (business owners’) interests to heart,” Kupfer said.

Carolyn Livingston, communications director for the Colorado Restaurant Association, said the increase is too severe.

“They cannot afford this,” Livingston said. “We polled our members last year and they said they were going to have to reduce hours, reduce employees and might introduce technology.”

Livingston said that while for most employees the proposed jump in four years represents a 40 percent increase, for the restaurant industry it’s closer to 70 percent. That’s because state law says employers can only reduce the minimum wage amount by $3.02 to account for income generated by tips. Assuming most restaurant owners do that, a server’s wage will jump from $5.29 an hour to $8.98 an hour.

Jeff Rogoff, co-owner of Sazza, a restaurant in Greenwood Village, supports the proposed amendment.

“In our ten years of operation, we have seen results that show if we pay our staff higher wages, we have a better retention rate and we spend less money on hiring and training so we are able to keep our best employees and keep our high standards of service at the levels our customers expect,” he said in a statement included with an announcement about making the ballot.

There are seven other ballot measures pending verification of signatures with the Secretary of State’s Office.

A ballot measure to hike the minimum wage was certified by the Secretary of State Thursday. (AP file)