Before receiving the assessment records, the treasurer of each county into which the district extends, shall furnish a corporate surety company bond, at the expense of the district, executed to the district, in a sum not less than the probable amount to be collected by him for the district during any one year, conditioned that said treasurer shall as hereinbefore provided pay over and account for all assessments so collected by him. Said bond after approval by the board shall be deposited with the clerk who shall produce the same for inspection and use as evidence whenever and wherever lawfully required so to do.