Twenty-five proposed tax-increase ballot measures were filed late Friday with the legislature’s administrative office, another part of the effort to reform Colorado’s school funding system.

Colorado CapitolAlmost of the draft measures propose various increases in the state income tax to fund increased K-12 education spending. Two additional measures were filed earlier by a Tea Party activist.

Democratic Sens. Mike Johnston of Denver and Rollie Heath of Boulder have proposed sweeping changes to the state’s formula for funding schools, a bill now working its way through the Senate. (See this EdNews story for the most recent developments.)

If that measure is approved by the legislature, the new system wouldn’t go into effect unless voters approve a tax increase to pay for it. Various Johnston allies have been working on tax plans, and those were filed Friday.

Filing multiple, slightly different versions of a ballot measure is a fairly common tactic. It’s done for a couple of reasons. Sometimes versions are thrown out because they don’t meet constitutional requirements for ballot language, so backers want to have something in reserve. Proponents also like to have multiple measures to choose from to maximize chances of voter approval based on polls and focus groups. Only one version ultimately goes to voters.

Sixteen variations of a measure were filed by the Colorado Forum, a business groups that works on constitutional and fiscal reform issues. Another group of measures was filed by Bruce Broderius, a former member of the Greeley school board and a longtime advocate of increased school funding. It couldn’t be determined Friday evening what group or groups he represents.

A measure filed by Kelly Brough, CEO of the Denver Metro Chamber of Commerce, and Tamara Ward, CEO of Colorado Concern, would propose the text of SB 13-213 to the voters as an initiated law. That appears to be a backup if the bill itself doesn’t pass the legislature.

Friday was the deadline for proponents of ballot measures to file the proposed texts for issues intended for the November 2013 ballot. Following a review process, final versions must be submitted to the secretary of state’s office by April 5. Measures are then subject to another round of review (which sometimes gets detoured through the Colorado Supreme Court) that ends April 26. Backers of surviving measures than have until Sept. 4 to gain enough signatures to get their final version on the November ballot.

Two measures filed Thursday by Tea Party activist Steve Dorman propose a 10 percent sales tax increase to fund teacher pensions and a miniscule income tax increase to fund schools.

Find links to the proposed measures here. (Warning: Contains complicated legal language.)