The directors are hereby empowered to acquire the necessary right of way and property of any kind or character whatsoever for all necessary improvements contemplated by this chapter, by gift, grant, purchase or condemnation proceedings, within or without the boundaries of the district; and any property acquired may be conveyed to the United States in so far as the same shall be necessary for the construction, operation and maintenance of works by the United States under any contract that may be entered into between the district and the United States.