Colo. Const. art. II, § 15

Taking property for public use - compensation, how ascertained. Private property shall not be taken or damaged, for public or private use, without just compensation. Such compensation shall be ascertained by a board of commissioners, of not less than three freeholders, or by a jury, when required by the owner of the property, in such manner as may be prescribed by law, and until the same shall be paid to the owner, or into court for the owner, the property shall not be needlessly disturbed, or the proprietary rights of the owner therein divested; and whenever an attempt is made to take private property for a use alleged to be public, the question whether the contemplated use be really public shall be a judicial question, and determined as such without regard to any legislative assertion that the use is public.