Owners of land may drain the same in the general course of natural drainage by constructing an open ditch or tile drain, discharging the water therefrom into any natural watercourse or into any natural depression or draw, whereby such water may be carried into some natural watercourse; and when such drain or ditch is wholly on the owner's land, he shall not be liable in damages therefor to any person or corporation.
Neb. Rev. Stat. §§ 31-201