Whenever fifty, or a majority of the holders of title to, or of evidence of title to, lands susceptible of irrigation in each of the several counties in which lands coming within the proposed district are located, desire to organize an irrigation [reclamation] district for any, or all, of the purposes mentioned in RCW 89.30.007, they may propose the organization of an irrigation [reclamation] district by filing a petition signed by the required number of holders of title, or evidence of title, to land within the proposed district with the board of county commissioners of the county in which the greatest portion of the land susceptible of irrigation, to be included in the proposed district, is located.