7-7-4628. Payment of bonds. (1) In order that the payment of the refunding bonds and interest thereon shall be adequately secured, any municipality issuing refunding bonds pursuant to this part and the proper officers, agents, and employees thereof are hereby directed and it shall be the mandatory duty of such officers, agents, and employees under this part and it shall further be of the essence of the contract of such municipality with the bondholders, at all times:

(a) to pay or cause to be paid punctually the principal of every refunding bond and the interest thereon on the date or dates and at the place or places and in the manner and out of the funds mentioned in such refunding bonds and in the coupons thereto appertaining and in accordance with the resolution authorizing their issuance;

(b) to preserve and protect the security of the refunding bonds and the rights of the holders thereof and warrant and defend such rights against all claims and demands of all persons whomsoever;

(c) to hold in trust the revenues pledged to the payment of the refunding bonds for the benefit of the holders of the refunding bonds and to apply such revenues only as provided by the resolution authorizing the issuance of the refunding bonds, or if such resolution shall thereafter be modified in the manner provided therein or herein, only as provided in such resolution as modified.

(2) None of the foregoing duties shall be construed to require the expenditure in any manner or for any purpose by the municipality of any funds other than revenues received or receivable from the enterprise.