Idaho Code § 43-1817
If the bonds of the district are not deposited with the United States as authorized in this chapter, it shall be the duty of the board at its regular meeting in September of each year to include as part of any levy or assessment authorized under section 43-704 an amount sufficient for all payments each year due or to become due the ensuing year to the United States under the terms of any such contract with the United States. When collected the assessment shall be paid into the district treasury and shall constitute a special fund to be called "U.S. contract fund of .. irrigation district."
Provided, however, that the board of directors of any irrigation district which shall have entered into a contract providing for payments to the United States under any of the Federal reclamation laws, at its option, at any meeting of said board of directors held prior to the first day of December of each year, may include such amount as part of any such levy or assessment, instead of at its said regular meeting in September; and, provided further, that said board of directors, at said meeting, at its option, may also adopt and enter a resolution authorizing a discount of not to exceed ten per cent (10%) for payment of such assessments in full on or before the third Monday of December of each year, and authorizing the levy of assessment in such an amount that said discount can be allowed without reducing collections below the required amount, in which case notice of such assessment or levy or resolution as to discount shall be promptly published once a week for two (2) consecutive weeks in a newspaper published in the county or counties in which the district is located.
Idaho Code § 43-1817