36 Pa. Stat. § 670-772
Whenever any county bridge is carried away or destroyed by flood or windstorm, the department shall rebuild the same, if and when the General Assembly shall have made a specific appropriation for such purpose, whether or not such bridge has been previously rebuilt by the department.
In order to facilitate public travel and eliminate grade crossings, the department, if the viewers appointed as hereinafter provided so recommend, may rebuild such bridge and the necessary approaches thereto at a lower or higher elevation than the former bridge, or may rebuild the same upon a new site: Provided, That the expenses to the State shall be limited to the sum required to construct a bridge of the dimensions and character of the old bridge destroyed or carried away and at the old site and elevation. The department in preparing the plans and specifications, shall determine the amount of such sum.
36 P.S. § 670-772