Within any area classified “designated floodway” by the department or board after completion of a federal project report the appropriate public agency shall establish the necessary flood plain regulations within one year following notification by the department or board. The state shall not pay any of the cost of lands, easements, and rights-of-way associated with the flood control project as set forth in the project report of the federal agency unless flood plain regulations for the designated floodway are adopted in accordance with the requirements of this chapter.