The Municipality may, by notice require the owner or occupier of a building to remove or to alter a projection or structure overhanging, projecting into or encroaching on a street, or into, on or over any drain, sewer or aqueduct therein ;
Provided that in the case of any such projection or structure lawfully in existence on or before the 10th day of March, 1900, the Municipality shall make compensation for any damage caused by the removal or alteration, which shall not exceed ten times the cost of erection and demolition.