The Board, at or before the time any such project is acquired by purchase or by condemnation, shall determine what repairs, replacements, additions, or betterments will be necessary to place the project in safe and efficient condition for the use of the public and shall cause an estimate of the cost of such improvement to be made. The Board shall authorize such improvements before the sale of any revenue bonds for the acquisition of such project, and the cost of such improvements shall be paid for out of the proceeds of such bonds.