(1) The board has power in connection with any improvement district to issue, on the behalf and in the name of the urban district, bonds in an amount not exceeding the estimated cost of the project or part thereof to be defrayed by the levy and collection of assessments, or if the bonds are issued after the levy of assessments, in an aggregate principal amount not exceeding the aggregate amount of unpaid assessments pledged for the payment of the bonds as provided in sections 32-11-501 (3) and 32-11-502 to 32-11-526 and elsewhere in this article, except as otherwise provided in sections 32-11-622 to 32-11-631.

(2) Any assessment bonds may be issued at public or private sale to defray the cost of the project, including any temporary advances evidenced by assessment debentures or otherwise and all proper incidental expenses.

(3) The board may enter into a contract to sell assessment debentures and assessment bonds at any time; but, any other provisions of this article notwithstanding, if the board so contracts before it awards a construction contract or otherwise contracts for acquiring or improving, or acquiring and improving, the project, the board may terminate the contract to sell such securities if, before the awarding of the construction contract or otherwise contracting for the acquisition or improvement, or acquisition and improvement, of the project, the board determines not to acquire or improve, or acquire and improve, the project, and if the board has not elected to proceed under section 32-11-615 other than by independent contract pursuant to section 32-11-615 (1)(a), if at all.