In any case in which the entry and activities mentioned in Section 1245.010 will subject the person having the power of eminent domain to liability under Section 1245.060, before making such entry and undertaking such activities, the person shall secure:
(a) The written consent of the owner to enter upon his property and to undertake such activities; or
(b) An order for entry from the superior court in accordance with Section 1245. 030.