La. R.S. 33:4406

No public utility shall begin the construction of any new plant, equipment, property, or facility, which is not in substitution of an existing plan, property, equipment, or facility, nor shall it make any extension or addition to any existing plant, property, equipment, or facility which will cost over two per cent of the rate-making value of the property at the time the extension or addition is made, nor shall any indeterminate permit or franchise be granted, unless and until the governing authority of the city certifies that public convenience and necessity require the same. The governing authority of such city shall be the sole and final judge of what the public convenience and necessity require, in every case.