In lieu of the issuance of bonds or the levy of taxes or assessments as otherwise by law provided, and in lieu of any other lawful methods or means of providing for the payment of indebtedness, any irrigation district within this state shall have the power and authority, by and through its board of directors, to provide for or to secure the payment of the cost or expense of purchasing, constructing or otherwise acquiring, extending and improving any real or personal property necessary or useful in its operation of any electric light and power plant, distribution system, or transmission lines, by pledging, assigning, or otherwise hypothecating the net earnings or profits of such irrigation district derived, or to be derived, from the operation of such electric light and power plant, distribution system, or transmission lines, and to that end, to enter into such contracts and to issue such warrants or debentures as may be proper to carry out the provisions of this section. All earnings, profits, and revenue thus pledged, assigned or hypothecated shall be kept in separate funds to be expended for the specific purposes aforesaid, until such indebtedness shall have been fully paid. Warrants or debentures issued under the provisions of this section shall not be subject to the provisions of law requiring the judicial examination of the issuance and sale of bonds of the district.