Nothing contained in this article shall be construed to prevent any person from maintaining any pipe or conduit in any public highway by virtue of any law, ordinance, franchise or permit or from making such excavation as may be necessary for the preservation of life or property when such necessity arises during such hours as the offices of the city are closed; provided, that the person making such excavation shall obtain a permit therefor within one day after the office of the director of public works is first opened subsequent to the making of such excavations. (1954 Code §19.19; amd. 1994 Code)