Before the issuance of any bonds or certificates as herein provided, the Board shall fix and establish rates, charges and fees for the use of facilities acquired, constructed, reconstructed, extended or improved with the proceeds derived from the sale of such bonds, sufficient at all times with all other revenues of the District, to pay: (a) the cost of maintaining, repairing, regulating and operation of the facilities; and (b) the bonds or certificates and interest thereon as they shall become due; and (c) all sinking fund and other requirements provided by the ordinance authorizing the issuance of the bonds or certificates or as provided by any trust agreement executed to secure payment thereof.