The cost of the works shall be deemed to include the cost of acquisition or construction thereof, the cost of all property, rights, easements, and franchises deemed necessary or convenient therefor and for the improvements determined upon as provided in this article; interest upon bonds prior to and during construction or acquisition and for six months after completion of construction or of acquisition of the improvement last mentioned; engineering and legal expenses; expense for estimates of cost and of revenues; expenses for plans, specifications and surveys; other expenses necessary or incident to determining the feasibility or practicability of the enterprise, administrative expense, and such other expenses as may be necessary or incident to the financing herein authorized and the construction or acquisition of the works and the placing of the works in operation and the performance of the things herein required or permitted in connection with any thereof.