It shall be proper to provide with respect to any bonds now required to be amortized or payable serially, that the annual maturities for the first five (5) maturities shall be of such annual principal amounts as may be fixed by any such governing authority, and that such amortized or serial annual maturities shall commence to be payable at any time on or before five (5) years after the date of said bonds, and that any bonds, or any part thereof, issued under the authority of this act, shall be redeemable prior to their fixed maturities and at the option of the issuer, as provided by the governing board or authority of any such issuer.
Idaho Code § 57-228