If the contractor has furnished the community improvement district all required records and reports, the community improvement district shall pay the contractor interest at the rate specified in section 39-1349, as such rate may from time to time be adjusted by the Legislature, on any contract amount retained and the final payment due the contractor beginning twenty days after completion of the work covered by the contract under section 18-3528. The contractor shall notify the community improvement district in writing that the work has been completed and the community improvement district, within twenty days after receipt of such notice, shall give written notice to the contractor of any objections by the community improvement district to acceptance of the work.