Said bonds shall be numbered from one (1) upward, consecutively, and be in denominations of not less than $100 nor more than $1000. They shall bear the date of issue, shall be made payable to the bearer and bear interest, payable semi-annually, with coupons attached for each interest payment. The bonds shall be signed by the chairman of the board of drainage commissioners, and shall be attested by the secretary of said board, and the seal of such district shall be affixed to each bond, but not to the coupons. The coupons may be signed by the facsimile lithographed or engraved signatures of the said officers.
The board of commissioners shall fix the maturities of said bonds not exceeding forty (40) years from the date of their issuance and an amortization period which shall be not less than three-fourths (3/4) of the maximum maturity. During the first fourth of the period covered by the last maturity provision may be made, in the discretion of the board, for the payment of interest only. Maturities shall be so arranged that during at least the latter three-fourths (3/4) of the period covered by the last maturity the principal shall be amortized by payments thereof in annual or semi-annual instalments so arranged as to maturities that the combined principal and interest payments during the amortization period shall be approximately the same each year. Said bonds shall be payable at such place within or without the state of Idaho as may be designated by the board of commissioners. The issuing drainage district may reserve the right to redeem said bonds or any of them at any time after ten (10) years from date thereof.