Whenever the public interest, welfare, convenience and necessity require that a city or town acquire water rights for the purposes set forth in RCW 35.92.220, as now or hereafter amended, and that such water rights be acquired through the purchases of shares in a water users' association or corporation, such city or town shall have full authority and power to acquire, or to hold in trust, such shares as shall be necessary for said purposes.
RCW 35.92.263