[1] In this context, land drainage refers to the responsibilities and activities of "internal drainage districts" and "internal drainage boards", both of which are specifically defined by relevant legislation.
The land drainage responsibilities of the boards and districts are limited to works on main rivers.
Such works encompass any reasonable activity to maintain an adequate channel in the river to carry a 1 in 100 year river flow event.
Such activities may include dredging, weed clearing, the raising of flood embankments etc.
This article related to a river in the United Kingdom is a stub.