Do you live next to a watercourse?

This can mean a ditch, stream, or river.  The details here explain the rights and responsibilities of property owners and residents whose property is adjacent to a river, stream, brook, drainage ditch, culvert or other watercourse.

What is a watercourse?

A watercourse is defined as any channel through which water flows and can be open or enclosed underground as a culvert. This includes any channel that takes seasonal flows and may at times be dry. Watercourses may be classified as either 'main rivers' or 'ordinary watercourses'.

Main Rivers

Main rivers are usually larger streams and rivers (like the River Thames or the River Thame), but also include smaller watercourses of strategic drainage importance (like the River Ock and the River Stert in Abingdon). A main river is defined as a watercourse shown as such on a main river map and can include any structure or appliance for controlling or regulating the flow of water along its course, in or out of a main river.  The Environment Agency has powers to carry out flood defence works applying to main rivers only.

Ordinary Watercourses

An Ordinary watercourse is every river, stream, ditch, drain, cut, dyke, sluice, sewer (other than a public surface water sewer or highway drain) and passage through which water flows which does not form part of a main river.  Watercourses occur naturally, they serve to drain the land and assist in supporting animal and flower life.  Historically, watercourses have taken water run off from buildings and roads, as well as fields and parks. In the process of development many have been culverted or changed in other ways.

In normal conditions the watercourse may be a dry channel in the ground.  In storm conditions it may become a raging torrent.

Riparian responsibilities

If you live or you own property that is next to any watercourse that flows through your property you are a 'riparian landowner' and you have 'riparian' rights and responsibilities which have been established in common law for many years.

If the land on the other side of the watercourse is owned by a third party then it is likely that that person is the joint riparian owner for the length of watercourse adjacent to the boundary. Unless the landowners’ deeds show otherwise, it is presumed that each party owns to the centre line of the watercourse.

A riparian owner is responsible for accepting water from their upstream neighbour and transferring this, along with any existing drainage from their own property, freely, to their neighbour downstream.  Further riparian landowner’s responsibilities are detailed as follows:

  • Responsibility to pass on flow without obstruction, pollution or diversion affecting the rights of others.
  • Accept flood flows through their land, even if caused by inadequate capacity downstream. There is no common law for a landowner to improve the drainage capacity of a watercourse.
  • Maintain the bed and banks of the watercourse (including trees and shrubs growing on the banks) and for clearing any debris, natural or otherwise, including litter and animal carcasses, even if it did not originate from their land.
  • Must not cause any obstructions either temporary or permanent that would prevent the free passage of fish.
  • Responsible for keeping the bed and banks clear from any matter that could cause an obstruction either on their land or by being washed away by high flow to cause an obstruction at a structure downstream. Rivers and their banks should not be used for the disposal of any form of garden or other waste.
  • Must keep any structures clear of debris. These structures include culverts, trash screens, weirs and mill gates.
  • The responsibility for protecting the property from seepage through natural or man-made banks. Where such seepage threatens the structural integrity of a flood defence it may become the concern of the Environment Agency.


Purchasers of property rarely read the conveyance document but Section 26 of the Law of Property Act 1925 provides that "a conveyance of land shall be deemed to include and shall by virtue of this Act operate to convey with the land all buildings, hedges, ditches, fences, ways, waters, watercourses, liberties, easements, rights and advantages whatsoever appertaining or reputed to appertain to the land or any part thereof". However, this section operates in the absence of any contrary intention expressed in the conveyance.

If you wish to change the watercourse

Plans for any works on ordinary watercourses other than general cleaning and routine maintenance such as the removal of weeds or debris must be approved by Vale of White Horse District Council who are acting on behalf of Oxfordshire County Council as Lead Local Flood Authority. Consents for the work must be secured before starting any work.  This applies to any modifications which might affect the flow characteristics or capacity and include installation of dams, weirs, mills, channel diversions and in particular, culverting or piping. Examples of the types of changes to watercourses that require consent. (297.2 KB) PNG image

What happens if ordinary watercourses are not maintained?

The riparian owner must not cause or perpetuate a nuisance, such as causing obstruction to the flow of water in a stream by causing the channel to become blocked.  Vale of White Horse District Council have no responsibilities (except where it is a landowner) for land drainage.  However, it has permissive powers and can (but is not obliged to) serve notice on individuals and carry out works in default if watercourses have become blocked resulting in a flood risk or a health hazard.   These powers are contained in the Land Drainage Acts 1991 and 1994, and sections 259 – 265 of the Public Health Act 1936.

The Oxfordshire County Council as Lead Local Flood Authority (LLFA) has a responsibility to investigate flood incidents under Section 19 of the Flood and Water Management Act 2010. 

The LLFA also has powers under Sections 23, 24 and 25 of the Land Drainage Act 1991 with regard to issuing of consents, enforcement against un-consented works and general enforcement of riparian landowner duties.

Following is summary of the two most relevant sections of the Land Drainage Act 1991 to the Local Authority:

  • Section 14: Power for a local authority to perform works for the prevention or mitigation of flooding risk other than in connection with a main river or the banks or within an internal drainage board area.
  • Section 25: The power to serve notice on persons requiring them to carry out necessary works to maintain the flow of any water course and the power to carry out works in default and recover its reasonable expenses should the riparian owner fail to carry out their responsibility.

Section 15: Disposal of or deposit matter removed from a water course on land adjoining the water course.

For more information or if you have any concerns please contact the Flood Risk Management Team on 01235 422679.

Last reviewed: 02 - 05 - 2018

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