(1) If:
(a) this Part would result in an acquisition of property; and
(b) this Part would not be valid, apart from this section, because a particular person has not been compensated;
the Commonwealth must pay that person:
(c) a reasonable amount of compensation agreed on between the person and the Commonwealth; or
(d) failing agreement--a reasonable amount of compensation determined by a court of competent jurisdiction.
(2) Any damages or compensation recovered, or other remedy given, in a proceeding begun otherwise than under this section must be taken into account in assessing compensation payable in a proceeding begun under this section and arising out of the same event or transaction.
(3) In this section, acquisition of property has the same meaning as in paragraph 51(xxxi) of the Constitution.