Cal. Public Utilities Code - PUC § 29590. Section 29590.
When the district is the sole owner of any tract of land within the County of San Mateo upon which is located works and facilities of the district, the board, upon determining that the inclusion of that land will be for the best interests of the district, may, by resolution, declare that such land shall be included in the district. The inclusion of such land within the district is effective immediately upon the adoption of the resolution.