Cal. Sts. & High. Code § 5301

If any lot or parcel of land belonging to the United States, or to the State, or to any county, city, public agent, mandatory of the government, school board, educational, penal or reform institution or institution for the feebleminded or the insane, is in use in the performance of any public function, and is included within the district to be assessed to pay the costs and expenses thereof, the legislative body may, in the resolution of intention, declare that such lots or parcels of land, or any of them, shall be omitted from the assessment thereafter to be made to cover the costs and expenses of the work.