Cal. Water Code § 9535

If both portions of the installments, levied pursuant to Chapter 6 of this part, are not paid before the last Monday in April at 6 o'clock p.m., the board shall publish in each county where the delinquencies exist, in one notice, a list of all the delinquencies in the county at least once a week for two weeks successively in some newspaper of general circulation published in the county.