(1) The board is authorized to establish a countywide flood control zone district incorporating the boundaries of any and all watersheds located within the county which are not specifically organized into flood control zone districts established pursuant to chapter 86.15 RCW. Upon establishment of a countywide flood control zone district as authorized by this section, the board is authorized and may divide any or all of the zone so created into separately designated subzones and such subzones shall then be operated and be legally established in the same manner as any flood control zone district established pursuant to chapter 86.15 RCW.

(2) Countywide flood control zone districts shall be established pursuant to the requirements of RCW 86.15.020, 86.15.030 and * 86.15.040 as now law of [or] hereafter amended. Subzones established from countywide flood control zone districts shall be established by resolution of the board and the provisions of RCW 86.15.020, 86.15.030 and shall not apply to the establishment of such subzone as authorized by this section.

(3) Such subzones shall be operated and administered in the same manner as any other flood control zone district in accordance with the provisions of chapter 86.15 RCW.

(4) Such subzones shall have authority to exercise any and all powers conferred by the provisions of RCW 86.15.080 as now law or hereafter amended.

(5) The board shall exercise the same power, authority, and responsibility over such subzones as it exercises over flood control zone districts in accordance with the provisions of chapter 86.15 RCW as now law or hereafter amended, and without limiting the generality of this subsection, the board may exercise over such subzones, the powers granted to it by RCW 86.15.160, 86.15.170, 86.15.176 and 86.15.178 as now law or hereafter amended.

*Reviser's note: RCW 86.15.040 was repealed by 1991 c 322 § 13.