Notwithstanding the provisions of this Chapter, overhead facilities may be installed and maintained for a period, not to exceed ten (10) days, without authority of the City Engineer in order to provide emergency service. The City Engineer may grant special permission, on such terms as the City Engineer may deem appropriate, in cases of unusual circumstances, without discrimination as to any person or utility, to erect, construct, install, maintain, use or operate poles, overhead wires and associated overhead structures.