California Code, Water Code - WAT § 51206

(a) Prior to the levy of any installment upon an original or additional assessment, or the levy of an operation and maintenance assessment, in one or more installments, by a district pursuant to this division, notice shall be given by publication once a week for two successive weeks in a newspaper of general circulation published in the principal county of the intent to levy an installment or operation and maintenance assessment, together with the time and place for a public hearing to be held by the board to consider and adopt an installment or assessment levy.

(b) If an installment upon an original or additional assessment or an operation and maintenance assessment levy has been approved by the board at a noticed public hearing, notice of subsequent installments or operation and maintenance assessments shall be required only if the amount of the installment or assessment levy is proposed to be increased.