Any ordinance authorizing the issuance of general obligation securities or special obligation securities payable from gross revenues or any indenture or other proceedings appertaining thereto may contain a covenant of the municipality that to the extent required, as provided therein, the municipality 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 municipality shall levy taxes therefor.
NRS 350.584