California Code, Water Code - WAT § 74071

On the final hearing the board of supervisors shall make such changes in the proposed boundaries as may be deemed advisable, and shall define and establish such boundaries.  The board of supervisors shall not modify such boundaries so as to exclude from the proposed district any territory which would be benefited by the formation of the district;  nor shall any land be included within the proposed district which will not, in the judgment of the board, be benefited by the formation of the district.