It shall be unlawful for any person to make an excavation of any kind, nature or description in the streets or alleys of the city without first obtaining permission of the public works director and posting a bond in such an amount or sum as may be fixed by the city council protecting the same city from any damage that might or could result from the making of such excavation. Bond shall be refunded upon completion of excavation and refilling of trench and with final approval of the public works director. (Res. 1993-R11, 4-26-1993; amd. 1999 Code)