When the purpose for which such excavations or alterations have been accomplished by the person obtaining the permit therefor, all such excavations made, or trenches or ditches dug or other alterations made, shall be filled up, firmly tamped, and the surface of any street, avenue or alley affected placed in a durable, smooth and serviceable condition and in as good condition as it was before such work was done by the street department of the city under the supervision of the street superintendent. (1985 Code § 14-303)