The district may take by grant, purchase, gift, devise, or lease, or condemn in proceedings under eminent domain, or otherwise acquire, and hold and enjoy, real and personal property of every kind within or outside the district and necessary to the full or convenient exercise of its powers. The board may lease, mortgage, or otherwise encumber, or sell, or otherwise convey or dispose of, any real or personal property within or outside the district when, in its judgment, it is for the best interests of the district to do so.