Cities of the metropolitan class; drainage; cleaning out watercourse; special assessments.

The city council of a city of the metropolitan class upon receipt of a request pursuant to section 31-229, may, if it finds that natural flow is being obstructed, cause the natural watercourse to be cleaned out. Except as provided in section 31-221, the cost thereof may be levied as a special assessment and apportioned among the property owners specially benefited thereby and collected in the same manner as special assessments are levied and collected.