If any county treasurer or other person entrusted with the collection of assessments fails to make prompt payment of the assessments, or any part of them, when collected under this chapter to the treasurer of the conservancy district upon the presentation of a proper demand, the county treasurer or other person shall forfeit ten per cent on the amount of the delinquency. The forfeiture shall at once become due and payable, and both the county treasurer or other person and the sureties of the county treasurer or other person shall be liable for the failure on the official bond of the county treasurer or other person. The county treasurer shall retain for the treasurer’s services one per cent of the amount the treasurer collects on delinquent assessments.