All bonds issued by a district pursuant to this chapter shall be, and shall recite upon their face that they are, payable both as to principal and interest, and as to any premiums upon the redemption thereof, out of the revenues pertaining to the electric system on account of which the indebtedness evidenced by such bonds was created, and not out of any other fund or moneys of the district.

(Added by Stats. 1957, Ch. 2237.)