Okla. Stat. tit. 19, § 19-891: Costs and expenses - Paid out of construction fund

The cost and expense of purchasing and acquiring property and

constructing the works and improvements herein provided for shall be

wholly paid in cash or in the bonds of said district issued as

hereinbefore provided at their par value with accrued interest. The

bonds may be issued in series or installments, and shall be turned

over and delivered to the contractor in payment of the amount due in

accordance with the terms of his contract, including advertising,

engineering, and other expenses. Said bonds shall be executed and

delivered from time to time on completion and approval of the work

or any part thereof, to an amount equal to the cost and expense of

purchasing and acquiring property and constructing the works and

improvements so completed and accepted. Such bonds or any portion

thereof may be sold for cash at not less than par and accrued

interest, within the discretion of the board of directors.