C.R.S. § 32-11-542

There is by this article, and there shall be by resolution authorizing the issuance of any indebtedness contracted in accordance with the provisions of this article, specially appropriated the proceeds of such taxes to the payment of the principal thereof and any interest thereon; and such appropriations shall not be repealed nor the taxes postponed or diminished, except as otherwise expressly provided in this article, until the principal of and interest on the district securities evidencing such debt or other indebtedness evidenced by other contract have been wholly paid.