Wat. Code, § 36455

Whenever, in the opinion of the board, the public interest or convenience may require, the board may order the acquisition or construction in, under, or upon the whole or any portion of any one or more of the streets or public places of the district, or any property or rights-of-way owned by the district, of any work or improvement for the production, storage, transmission and distribution of water for irrigation, domestic, industrial and municipal purposes, or for collecting, treating, and disposing of sewage, waste and storm waters, and provide that the cost thereof shall be assessed upon any district to be assessed therefor, which district need not be composed of lands contiguous to each other.