NRS 350.602

There is by the Local Government Securities Law, and there shall be by ordinance authorizing the issuance of any indebtedness contracted in accordance with the provisions of the Local Government Securities Law, specially appropriated the proceeds of such taxes to the payment of such principal and interest; and such appropriations shall not be repealed nor the taxes postponed or diminished (except as herein otherwise expressly provided) until the principal of and interest on the municipal securities evidencing such debt have been wholly paid.