Cal. Wat. Code § 31032.6
The county tax collector or district collector shall include the amount of the assessments on bills for taxes levied against the respective lots and parcels of land. Thereafter the amount of the assessments shall be collected at the same time and in the same manner and by the same persons as, together with and not separately from, the general taxes for the district, and shall be delinquent at the same time and thereafter be subject to the same delinquency penalties. All laws applicable to the levy, collection and enforcement of general taxes of the district, including, but not limited to, those pertaining to the matters of delinquency, correction, cancellation, refund and redemption, are applicable to such assessments.
Ca. Water Code § 31032.6