Cal. Government Code § 53521

Whenever by any law of this state a local agency is required to give notice by posting or publication of a hearing on the formation of a local agency or an improvement district, zone, special assessment district or special taxing district within a local agency, or on the consolidation or dissolution of such local agency or the annexation or detachment of territory to or from any of the foregoing, or on the issuance of bonds or other evidences of indebtedness by or for any of the foregoing, the local agency may, in its discretion, cause additional notice of such hearing to be given by mail as follows: (a) By mailing such notice, postage prepaid, to all persons owning real property which will be within such local agency, improvement district, zone, special assessment district or other special taxing district when the same is formed, consolidated or dissolved, or within territory proposed to be annexed or detached therefrom or which will or may be taxed or assessed for the payment of bonds or other evidences of indebtedness issued by or for any thereof, whose names and addresses appear on the last equalized county assessment roll (including the roll of state-assessed property) or are known to the clerk or secretary of the local agency. (b) Such notice shall be mailed at least fifteen (15) days prior to the date fixed for the hearing.