Subd. 1.   Partial prepayment of assessments permitted. After the adoption of an assessment roll pursuant to M.S. Chapter 429, as amended, and before certification of the assessment roll to the County Auditor, the City Administrator or other authorized official is authorized and directed to accept partial prepayment of the assessment, but not less than 50% of the total amount of any assessment and reduce the amount certified to the County Auditor accordingly. As provided by law, the partial prepayment may be accepted only during the 30-day period following approval of the assessment roll.
   Subd. 2.   Scope. This section shall apply to all assessment rolls which, on the effective date hereof, have been adopted by the Council, but not yet certified to the County Auditor, and to all assessment rolls subsequently adopted by the Council.
(`80 Code, § 2.71)