Flood control or stormwater control improvements may be extended, enlarged, acquired, or constructed by a zone pursuant to a resolution adopted by the supervisors. The resolution shall specify:

(1) Whether the improvement is to be extended, enlarged, acquired, or constructed;

(2) That either:

(a) A comprehensive plan of development for flood control has been prepared for the stream or water course upon which the improvement will be enlarged, extended, acquired, or constructed, and that the improvement generally contributes to the objectives of the comprehensive plan of development: PROVIDED, That the plan shall be first submitted to the state department of ecology at least ninety days in advance of the beginning of any flood control project or improvement; and shall be subject to all the regulatory control provisions by the department of ecology as provided in chapter 86.16 RCW; or

(b) A comprehensive plan of development for stormwater control has been prepared for the area that will be served by the proposed stormwater control facilities;

(3) If the improvement is to be constructed, that preliminary engineering studies and plans have been made, and that the plans and studies are on file with the county engineer;

(4) The estimated cost of the acquisition or construction of the improvement, together with such supporting data as will reasonably show how the estimates were arrived at; and

(5) That the improvement will benefit:

(a) Two or more zones, hereinafter referred to as participating zones; or

(b) A single zone; or

(c) The county as a whole, as well as a zone or participating zones.

Severability—1983 c 315: See note following RCW 90.03.500.