(1) If the works set out in the district water control plan are found insufficient to develop, in whole or in part, any or all of the lands of the district, the board of supervisors shall have the right to formulate a new or amended water control plan, containing new or modified public infrastructure or other authorized works, and additional assessments may be made in conformity with s. 298.305, the same to be made in proportion to the increased benefits accruing to the lands because of the additional works. Such new or amended plan shall be subject to review by the applicable water management district in accordance with s. 298.225. (2) If the board of supervisors determines at any time that the amount of total assessments levied under this chapter or the funds derived from the sale of bonds are insufficient to pay the cost of works set out in the water control plan, the board of supervisors may make an additional levy to provide funds to complete the works and, in addition, up to 10 percent of the total amount for contingencies; and, may issue bonds to finance the increased cost of completing the works described in the water control plan; however, the principal amount of the additional bonds and the principal amount of any bonds previously issued to finance the works must not, in the aggregate, exceed 90 percent of the benefits assessed.
(3) If the board of supervisors determines at any time that the water control plan requires modification and that the amount of the total assessments levied under this chapter or the funds derived from the sale of bonds are insufficient to carry out the water control plan with the proposed modification, the board of supervisors may initiate plan amendment proceedings.
(4) After the engineer’s report has been approved and the resolution amending the water control plan adopted by the board of supervisors, the board may levy a non-ad valorem assessment on all lands in the district to which benefits have been assessed to pay the increased cost of completing the works and improvements described in the water control plan as amended. The assessment may include the cost of maintaining and operating the facilities and all incidental expenses in connection therewith, plus an additional 10 percent of the total amount for contingencies. The additional assessments authorized to be levied under this section must be levied and collected in the same manner as the original assessments.
(5) The issuance of bonds under the provisions of this section must comply with the provisions of s. 298.47. Any additional tax authorized to be levied for completion of the works and improvements described in the water control plan must be apportioned to and levied upon each tract of land in the district in proportion to the benefits assessed against it and not in excess thereof; and, if bonds are issued, the amount of the interest that will accrue on the bonds, as estimated by the board of supervisors, must be included and added to the additional levy. The interest to accrue on the bonds must not be included as part of the cost of construction in the determination of whether or not the expenses and costs of making the improvements shown in the water control plan are equal to or in excess of the benefits assessed. 