It is unlawful to allow to grow any tree or shrub whose roots obstruct public or private storm drainage facilities. Wherever such plantings are shown to be obstructing public storm drainage facilities they shall be removed or otherwise remedied from obstructing said storm drainage facilities, at the expense of the property on which the planting grows. Such expense may become a lien on said property. (Ord. 5853 § 1, 2004; Ord. 5212 § 1 (Exh. J), 1999; Ord. 4492 § 4, 1991.)