Whenever any natural watercourse, as defined in section 31-228, within the corporate limits of a city of the metropolitan class, or within three miles thereof, is filled with trees, silt, or debris in such a manner as to obstruct the natural flow thereof and cause damage by flooding of adjacent lands, any five landowners owning land in the corporate limits of such city or within three miles thereof abutting on the natural watercourse may, by petition, request the city council to cause the same to be cleaned out and rendered free of obstructions.