Nebraska Revised Statutes Chapter 31. Drainage § 31-225. Watercourses, drains, or ditches;  annual clearing and deepening by landowner or tenant

It shall be the duty of any landowner or tenant who shall occupy or use land through which a watercourse, slough, drainage ditch or drainage course shall run or have its course, and who shall plow over or plant crops in the bed of such watercourse, slough, drainage ditch or drainage course, to dig out or by other means deepen, at least once a year, between March 1 and April 15, to a depth at least equal to that of such watercourse, drainage ditch, slough or drainage course, before same was plowed or seeded to crop, if plowing and planting as aforesaid causes an overflow or flooding of other lands along the course of said drainage ditch, slough or drainage course.