A bill that would create a felony DUI in Colorado is gaining momentum at the Capitol.

The House on April 10 gave initial approval to legislation that would require prison time for drunken drivers who rack up their third DUI in a seven-year period, or for their fourth total.

The bill would create a class 4 felony for such offenses, which carries a possible prison term of two to six years. Colorado is one of only a handful of states that does not have a felony DUI law.

The bill sponsor, Rep. Mark Waller, R-Colorado Springs, has been trying for the last few years to pass this type of legislation. However, his efforts have hit stumbling blocks, primarily due to the incarceration costs that come with the bill.

"It does cost money to engage in the protection of the individuals of the state of Colorado," Waller said.

This year's effort carries a hefty price tag as well. Last week, the House Appropriations Committee approved $2.9 million in general fund dollars for the bill to become a part of next year's budget.

The cost to the state will increase substantially over the next few years. The cost will rise to at least $15 million and then at least $26.8 million in subsequent fiscal years, according to an analysis by the Legislative Council.

Rep. Dan Pabon, D-Denver, thanked those who worked "so hard to find this money."

"This is an expensive bill," Pabon said. "This is an expensive cost to incarcerate this many offenders. And this money isn't just found."

Helping the legislation move forward was a compromise on treatment options that came out of a recent House Judiciary Committee hearing.

The compromise came about from growing concern over the bill not focusing enough on helping alcoholics and drug addicts receive treatment.

The amended version of the bill requires that courts consider "all reasonable and appropriate alternative sentences" before prison time becomes an option," the bill's fiscal note states.

Pabon said the "exhaustion of remedies" portion of the bill will ensure courts do everything they can "to put these people on the path to recovery before prison."

The House gave initial approval of the bill following an unrecorded voice vote on April 10. The bill was scheduled for a final vote on April 14, and was expected to advance to the Senate with large bipartisan support.

Although it has momentum, it is not a foregone conclusion that the bill will become law. Last year, the bill passed the House, but never received a vote in the full Senate.

But there are lawmakers on both sides of the aisle who want to see the measure become a reality.

"This is a very serious offense," said Rep. Beth McCann, D-Aurora. "We've talked about the fact that people need treatment and they get treatment, but it still doesn't keep them from driving."