- when effective
(1)No ordinance passed by the legislative body of any municipality shall take effect before thirty days after its final passage and publication, except an ordinance calling for a special election or necessary to the immediate preservation of the public peace, health, or safety, and not then unless the ordinance states in a separate section the reasons why it is necessary and unless it receives the affirmative vote of three-fourths of all the members elected to the legislative body taken by ayes and noes.
(2)Within thirty days after final publication of the ordinance, a referendum petition protesting against the effect of the ordinance or any part thereof may be filed with the clerk. The petition must be signed during the thirty-day period by at least five percent of the registered electors of the municipality registered on the date of final publication.
(3)If a referendum petition is filed, the ordinance or part thereof protested against shall not take effect, and, upon a final determination of petition sufficiency, the legislative body shall promptly reconsider the ordinance. If the petition is declared not sufficient by the clerk or found not sufficient in a protest, the ordinance shall forthwith take effect, unless otherwise provided therein.
(4)If, upon reconsideration, the ordinance or part thereof protested is not repealed, the legislative body shall submit the measure to a vote of the registered electors at a regular or special election held not less than sixty days and not more than one hundred fifty days after the final determination of petition sufficiency, unless otherwise required by the state constitution. The ordinance or part thereof shall not take effect unless a majority of the registered electors voting on the measure at the election vote in favor of the measure.
Section 31-11-105 — Ordinances - when effective - referendum,
https://leg.colorado.gov/sites/default/files/images/olls/crs2023-title-31.pdf (accessed Oct. 20, 2023).