Revenue bonds issued under the provisions of this article shall not be deemed to constitute a debt of the city or a pledge of the faith and credit of the city, but such bonds shall be payable solely from the funds provided therefor from revenues. All such revenue bonds shall contain on the face thereof a statement to the effect that neither the city nor the board shall be obligated to pay the same or the interest thereon except from revenues of the water system or sewer system in connection with which they are issued and that neither the faith and credit nor the taxing power of the city is pledged to the payment of the principal of or the interest on such bonds.

All expenses incurred in carrying out the provisions of this article shall be payable solely from funds provided under the authority of this article, and no liability or obligation shall be incurred by the board under this article beyond the extent to which moneys shall have provided under the provisions of this article.