A primary city is hereby authorized to acquire, either temporarily or permanently, lands, real or personal property or any interests therein, or any easements deemed to be necessary or desirable for any present or future necessary or authorized public purpose within or without the city by gift, agreement, purchase, condemnation, or otherwise. In all such cases the city shall make the person or persons whose property shall be taken or injured thereby adequate compensation therefor. The procedure to condemn property shall be exercised in the manner set forth in sections 76-704 to 76-724. A primary city shall have authority to enter upon any property to make surveys, examinations, investigations, and tests, and to acquire other necessary and relevant data in contemplation of establishing a location of a necessary or authorized public purpose, acquiring property therefor, or performing other operations incident to construction, reconstruction, or maintenance of such public purpose, and entry upon any property pursuant to this authority shall not be considered to be a legal trespass and no damages shall be recovered on that account alone. In case of any actual or demonstrable damages to the premises, the city shall pay the owner of the premises the amount of the damages. Upon the failure of the landowner and the city to agree upon the amount of damages, the landowner, in addition to any other available remedy, may file a petition as provided for in section 76-705. The entry by the city or its representatives shall be made only after notice of the entry and its purpose.