California Code, Water Code - WAT § 34157

The proposed district may include land situated in other distinctive district agencies of the State, including other water districts organized under the provisions of this division having different plans and purposes and the object of which is not the same.  The organization of any district prior to the enactment of this section and which included lands in one or more distinctive district agencies of the State, including other water districts organized under the provisions of this division having different plans and purposes and the object of which is not the same, is hereby ratified and confirmed.