Cal. Health & Safety Code § 14902

Before the arrival of the officer, board, or commission, or their representatives, any property owner may remove weeds at his or her own expense. Nevertheless, in any case in which an order to abate is issued, the board by resolution or motion may further order that a special assessment and lien be imposed pursuant to Section 14912. In that case the assessment and lien shall be limited to the costs incurred by the responsible agency in enforcing abatement upon the parcels, including investigation, boundary determination, measurement, clerical, and other related costs.