Title 44, Chapter 4, Section 8
When a watercourse is one of the boundary lines of a tract of land
and its course has been changed by nature or by man so that its
present channel cuts off a part of the land, the processioners and
the surveyor shall certify the fact; and the plat of the surveyor
shall plainly mark the original and present channels and shall
designate the exact quantity of land so cut off.