Any resolution authorizing the issuance of general obligation district securities payable from gross revenues or any indenture or other proceedings pertaining thereto may contain a covenant of the district that to the extent required, as provided therein, the district will pay operation and maintenance expenses by appropriation from its general fund and that to the extent the moneys accounted for therein are insufficient for that purpose the district shall levy taxes therefor, subject to the limitation pertaining to such expenses in section 32-11-217(1)(d).
C.R.S. § 32-11-530