Water Code § 51680
ARTICLE 2. Sale After One Year After Expiration of Redemption Period
After one year from the expiration of the period of redemption of any parcel sold to the county treasurer at a delinquency sale as trustee for the district, the county treasurer, when directed by the board, shall sell all or any part of any parcel remaining unsold to the highest bidder for cash at the front door of the courthouse of the principal county.