(a) Each assessment shall constitute a lien on the property assessed in the amount of the assessment with respect to that parcel of land, as provided in the final assessment, forecloseable as provided in this chapter. The assessment shall be payable either within 30 days after the final assessment or over such term as may be determined by the board. If the assessment is to be paid over a term, the assessment shall accrue interest and be payable periodically, monthly, quarterly, semiannually, annually, or as otherwise provided by the board, with interest at a rate as may be considered reasonable by the board. In particular, the assessment may bear interest at the same rate or yield borne by the bonds issued to obtain funds to acquire, construct, or install the improvements, but interest may be at a higher rate in the discretion of the board. Once the amount of a final assessment allocated with respect to a tract is paid in full, with all interest and penalties and costs of collection, if any, such tract shall be released from the lien of the assessment.
(b) The proceedings by which an assessment is levied may provide for an increased interest rate with respect to any interest accruing on any payment after the due date thereof.
(c) In its proceedings, the board may specify that assessments may be prepaid at any time or circumstance. The board may specify that assessments be prepaid upon the sale of the tract of land, or a portion thereof, being assessed. If the obligation to pay is accelerated, the assessment shall include all principal of the assessment then unpaid, plus interest until the next date provided for the payment of principal on any bonds secured by a pledge of the assessments, unless otherwise provided in the proceedings pursuant to which the bonds are issued.
(d) Unless otherwise provided in the proceedings of the board with respect to the assessment, any assessment may be voluntarily prepaid by the owner of the land assessed. In that case, the amount prepaid shall be applied first to interest until the first following date on which principal may be paid under the bond, and then to principal. However, if provided in the proceedings of the board with respect to the assessment, prepayments, whether voluntary or mandatory, the amount prepaid may be applied only to interest accrued to the date of the prepayment, and then to principal.
(e) Alternatively, the proceedings of the board with respect to the assessment may provide that prepayment shall be applied first to accrued interest, and then to the difference between: (1) interest that will accrue from the date of prepayment until the next principal payment on the bonds, and (2) the rate of interest at which the principal paid may be invested by the board to earn interest from the date of prepayment until the principal payment date, with any remaining balance to be applied to principal.
(f) The proceedings of the board with respect to the assessment may provide that any mandatory prepayment may be waived by the board on the terms as may be provided in a proceeding.
(g) If bonds are issued with respect to the final assessment, the assessments shall either (1) total the principal amount of the bonds to be issued with respect to the assessments or (2) total such principal amount multiplied by a coverage ratio (e.g., 1.2 to 1) providing debt service coverage for the bonds in the ratio desired by the board.