California Code, Water Code - WAT § 51613

Any person interested in the parcel may redeem it at any time within one year after the sale by paying to the county treasurer the amount for which it was sold, with interest thereon at the rate of 1 1/2 percent per month from the date of the sale, together with reasonable costs incurred by the county treasurer and the district as a result of the delinquency sale and redemption.