California Code, Streets and Highways Code - SHC § 5372.1

No assessment or bond hereafter levied or issued shall become a lien and no person shall be deemed to have notice thereof until a certified copy of the assessment and the diagram attached thereto shall be recorded in the office of the county surveyor if the improvement district or any part thereof is in unincorporated territory and with the superintendent of streets of the city or cities if the improvement district or any part thereof is in incorporated territory.