In case the said respective city has not agreed with the owner or owners for the damages done, or likely to be done, by the erection of said viaduct or bridge, it shall be lawful for the said city to take and appropriate the lands and property necessary, over and across which to erect said bridge or viaduct, and the damages and benefits caused by said taking and appropriation shall be assessed by three freeholders, as viewers, appointed by the court of common pleas, in the same manner and with like proceedings as is now, or shall hereafter be, provided by law in the opening of public streets.
53 P.S. § 2503