Complex sentence: Conversely, the southern half of its passage through Lincolnshire and its northern end, near Washingborough, are accepted as having had a raised bank on each side; one such on the upland side was not a feature well adapted to a catchwater drain.
Split into simpler sentences: Conversely, the southern half of its passage through Lincolnshire and its northern end, near Washingborough, are accepted as having had a raised bank on each side. However, the one on the upland side would not be a feature well adapted to a catchwater drain.