At the final hearing the board of supervisors shall determine the land to be formed into the proposed district:
(a)
Land shall be excluded which will not in the judgment of the board of supervisors be benefited by the project.
(b)
No land included by the petition in the proposed district or in the modified project as the case may be which is susceptible of irrigation from any of the proposed, or if modified, the modified sources shall be excluded unless the owner consents to the exclusion.
(c)
Riparian land and land already subject to irrigation may be included if in the judgment of the board of supervisors, it will either be benefited or the rights to the water used on it should be acquired by the proposed district.
(d)
Land not included in the original formation petition, susceptible of irrigation from any of the proposed sources, may in the discretion of the board of supervisors be included on application by its owner.