The board shall establish and collect rates and other charges for the sale or use of water, water connections, power, electric energy or other services sold, furnished, or supplied by the district which fees and charges shall be reasonable and nondiscriminatory and sufficient to produce revenue adequate:
Out of the revenues which may be received in excess of those required for the purposes specified in subparagraphs (a), (b), (c), (d) and (e) above, the board shall establish a reasonable depreciation and emergency fund, and retire (by purchase and cancellation or redemption) bonds issued under Section 861 et seq. of this title, or apply the same to any corporate purpose. It is the intention of the Grand River Dam Authority Act that the rates and charges of the district shall not be in excess of what may be necessary to fulfill the obligations imposed upon it by the Grand River Dam Authority Act.
Nothing herein shall be construed as depriving the State of Oklahoma of its power to regulate and control fees and/or charges to be collected for the use of water, water connections, power, electric energy, or other services, provided, that the State of Oklahoma does hereby pledge to and agree with the purchasers and successive holders of the bonds issued hereunder that the state will not limit or alter the power hereby vested in the district to establish and collect such fees and charges as will produce revenues sufficient to pay the items specified in subparagraphs (a), (b), (c), (d) and (e) of this section, or in any way to impair the rights or remedies of the holders of the bonds, or of any person in their behalf, until the bonds, together with the interest thereon, with interest on unpaid installments of interest and all costs and expenses in connection with any action or proceedings by or on behalf of the bondholders and all other obligations of the district in connection with such bonds are fully met and discharged.
Okla. Stat. tit. 82, § 868