The department or board shall review the adequacy of flood plain regulations established by a public agency to meet the requirements of Section 8411, and shall notify the appropriate public agency in the event the flood plain regulations are determined by the department or board to be inadequate to comply with the requirements of Section 8411. The department or board may recommend any provisions necessary to provide adequate flood plain regulations. Any such public agency shall within 180 days of receipt of the notice from the department or board, adopt new flood plain regulations. Upon their adoption a copy of such flood plain regulations shall be sent to the department or board.