An assessment is due from the time a certified copy is filed in the treasurer's office. Perpetual liens shall attach against assessed tracts, except those owned by the state and the United States, and, if an assessment is not paid within thirty days, a penalty of five percent shall attach and the assessment shall bear interest from the date of the order of the assessment at the Category D rate of interest as established in § 54-3-16, payable annually. The assessment shall be paid to the county treasurer and remitted to the holders of assessment certificates upon order of the board.
SDCL 46A-11-7