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Guidance for Riparian Owners

If you own land or property that contains or is adjacent to a river, stream or ditch, you are a ‘Riparian Owner’ and this guide contains a summary of your duties and responsibilities.

Who is a Riparian Owner?

Under common law you are the riparian owner of any watercourse if it is within or adjacent to the boundaries of your property. Where a watercourse is between two or more property boundaries (figure 1), it is assumed that each owner is responsible to the centre of the watercourse, unless it is known to be owned by someone else. For example, even if the ‘Title Deeds’ for Owner A’s property show the boundary to be the fence/wall (figure 2), they have riparian rights and responsibilities to the centre of the watercourse.

N.B. You have the right to protect your property against flooding from the watercourse and to prevent erosion of the watercourse banks or any structures.

Riparian Owner Responsibilities

As a riparian owner your responsibilities include the maintenance of the bank and bed of your section of watercourse or culverted section, to avoid it becoming blocked or overgrown.

Common Problems Affecting Watercourses

  • Failing to keep vegetation growth and silt under control.
  • Failing to keep pipes and culverts free of obstruction.
  • Failing to obtain consent for installing pipes or culverting of watercourses.
  • Disposal or storage of garden or domestic rubbish, waste etc. on the banks
  • of watercourses.

The Law

  • Section 23 of the Land Drainage Act- There is a legal requirement under section 23 of the Land Drainage Act to obtain consent from the relevant drainage authority before constructing any permanent structure such as bridges, culverts, dams, etc. and carrying out any other permanent or temporary works which is likely to affect the waterflow such as: damming, filling or diverting a watercourse without prior consultation and approval from the LLFA, the Environment Agency (EA), or the Internal Drainage Board (IDB).
  • Section 25 of the land Drainage Act – It may be an offence under section 25 of the land Drainage Act to leave a watercourse in such a condition that the flow of water is impeded. Failure to act on a notice served on the riparian owner(s) by the drainage authority, this may become a criminal offence.

For more information about applying for consent to carry out works in an ordinary watercourse from the Lead Local Flood Authority (LLFA) which is also Somerset Council, please visit:


Your responsibilities as a riparian owner have been established in common law such as:


To reduce the risk of flooding; the LLFA (Somerset Council) and the EA aim to improve the watercourse system through a process of co-operation, liaison, advice and assistance wherever possible. The enforcement of legislation may only resort, where it has not been possible to obtain the landowners cooperation. Any act that damages adjoining land or causes nuisance could result in private legal actions and lead to claims for damages.

What is a Watercourse?

A watercourse is any channel through which water flows, this can be open or enclosed. There are many different types of watercourses; ditch, stream, river, brook, channel, canal. In general terms, a watercourse is any channel that can convey water.

Watercourses occur naturally or can be man-made, they serve to drain the land and assist in supporting flora and fauna. Historically, watercourses have taken surface water runoff from buildings and roads, as well as fields and parks. In the process of development many have been culverted or changed in other ways.

Ordinary Watercourses

An ordinary watercourse is every river, stream, ditch, drain, cut, dyke, sluice, sewer (other than a public sewer) and passage through which water flows which does not form part of a main river.

Main Rivers

Main rivers are usually larger streams and rivers, but also include smaller watercourses of strategic drainage importance. 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 in, into or out of a main river. The EA’s powers to carry out flood defence works apply to main rivers only. The Department for Environment, Food and Rural Affairs (DEFRA) designates main rivers. If you require consent to carry out works on a main river, you should contact the EA.

Roadside Ditches

The riparian owner of any ditches alongside roads is normally the adjoining landowner, as the highway boundary invariably lies along the top of the bank closest to the road.

Unless it is general maintenance or any activities which does not require consent, adjacent landowners should not carry out any work on the ditch, which would interfere with the water flow or restrict road surface water draining into it. Although Somerset Council in its role as the Highway Authority, it has the right to discharge rainwater from the highway into these ditches, the adjoining landowner is responsible for maintaining it. However, if Somerset Council has created or piped the ditch under their highway powers, they become responsible for its maintenance.

Maintenance Works

Although general maintenance works might not require consent. However, maintenance activities which involves pumping, diverting flow or using any temporary structures such as dams and scaffoldings would require consent from the relevant drainage authority before carrying out the works.

Please refer to the ‘Cross sections of consentable activities’ guidance.

Any works to reduce the impact on the environment must be considered when carrying out works on a watercourse these are fundamental to biodiversity, flow regulation and water quality at the catchment scale.

The EA is responsible for enforcing the Hydromorphological Harm legislation. This means that if potential ‘harm’ is identified within an Ordinary Watercourse, the ‘responsible party’ (i.e. those undertaking the works or the landowner) would be liable to enforcement actions by the EA. The EA should be consulted in relation to fish and protected species, therefore, special provisions for fish and protected species may be required if those recommendations are made by the EA.

The above requirements should be read in conjunction with the Land Drainage Act 1991 and Water Resources Act 1991, Water Framework Directive (WFD); Land Drainage Consent will normally be required.

Staying Safe

When undertaking works within or adjacent to a watercourse, landowners must assess their works to ensure that they can be undertaken without putting themselves or others at any kind of risk. Due to the range of risks posed by both open and culverted watercourses, landowners should assess this on a case-by-case basis.

Trash Screens (grille)

A trash screen blocked with leaves or debris must be maintained regularly.

  • As poorly designed screens are prone to blockages and trash screens are a consentable activity, the design of screens must be approved by the relevant drainage authority and consent obtained prior to installation.

N.B. For more information on trash screens for ordinary watercourses outside of the drainage board area, please refer to theSummary of Requirements for Culverts:

Maintaining open ditches, streams and rivers

  1. a) Growth of vegetation (trees, weeds, reeds, grass ) should be kept under control when trimming vegetation, it is important to consider any impact on biodiversity. Mowing of banks around ditches should be minimised during the bird nesting season of March to mid-July. The nesting season is the time of year during which birds and some other animals, particularly some reptiles, build nests, lay eggs in them, and in most cases bring up their young.
  • Some trees may have tree protection orders (TPOs) on them so if in doubt check with your local planning authority.
  • For some tree removal or pollarding, you might require an environmental appraisal produced by an ecologist. A bat roosting survey might be required prior to the works and an ecologist present whilst the work is being carried out.
  • It is recommended to cut only up to just above the water level on one side of the watercourse, leaving the fringe of the bank uncut, thereby maintaining some habitat as well as enabling a free flow of water in the ditch.
  • Cuttings from any clearance work should be removed from the channel to avoid it causing blockages downstream. Putting removed material too close to the top of the bank can lead to it falling back in during times of flooding
  • It is worth noting that you don’t always have to remove all vegetation to allow water to flow. In fact, keeping some vegetation can be beneficial for wildlife and to prevent bank erosion. Large tree roots and dense vegetation are generally the main problems.
  1. b) Keep watercourses free of debris (e.g. litter, grass cuttings, and fallen trees and branches)
  • Remove any physical obstructions such as large rocks, rubble, fallen trees and branches and other waste materials (litter, grass cuttings etc.) so that water can flow freely.
  • All non-organic waste should be completely removed off site and disposed of in an appropriate manner.
  • Any green waste resulting from the maintenance of ditches can be left a safe distance from the bank for a few days to allow any organisms to move back into the watercourse, after which the green waste should be removed so it doesn’t wash back into the watercourse.
  • Ensure that any disturbed debris does not end up flowing downstream and causing problems for other landowners.

Do not store anything alongside the watercourse which may interfere with maintenance, affect the stability of the bank or get washed into the channel.

b) Remove excess silt

Silt naturally builds up in watercourses as vegetation dies back each year. It can quickly reduce the capacity of a watercourse or block pipes into or out of the watercourse.

Silt should be removed along the length of the ditch to ensure it flows properly in the right direction.

  • If there are any pipes into or out of the ditch you should remove silt to the same level or below the bottom of the pipe(s).
  • Where possible, try to maintain the original slope and cross section of the ditch when de-silting. If the slope of the ditch is altered it can change the flow pattern, cause erosion or increase flood risk either upstream or downstream.
  • If the silt is non-hazardous you can put it on the bank of the watercourse. Depositing silt on top of the banks of the watercourse allows for any organisms to move back into the ditch. However; it is essential that this material does not then block any other ditches or nearby roads, or stop water draining into the ditch if it would normally do so (e.g. from higher ground into the ditch). The silt must be deposited as close as possible to where it was dredged from either: on the bank of the waters from where it was taken or on land directly next to the watercourse.
  • If you think that the material may be hazardous – for instance if it contains oils or other waste – please see guidance online for methods of disposal or contact the EA for advice.

For piped or culverted watercourses

Piped or ‘culverted’ watercourses are prone to blockage or collapse and will degrade over time. Where they naturally silt up, they can be difficult to access and clean. Cleaning the inside of a culvert is likely to cost more than carrying out maintenance of an open watercourse, due to the specialist equipment required to access it.

A damaged pipe/culvert requiring repair or replacement

  • Health and Safety must be top priority when carrying out culvert maintenance and you should never enter any large culvert without seeking advice.
  • Blockages within the pipe or at the pipe entrance can cause flooding problems. These blockages can be reduced by regular inspection and the removal of debris.
  • Either you or a qualified drainage company should carry out regular inspections and clear any blockages or silt build up as soon as they occur. There are many drainage companies that can inspect and clear culverts.
  • Culvert entrances and exits often have protective grilles to prevent debris

entering the pipe and causing blockages. These should be inspected and cleared regularly, especially during the winter or periods of heavy rainfall when debris can accumulate very quickly.

  • Replacing sections of pipe culverts or making additional connections to a pipe or culvert is a consentable activity. Consent must be obtained from the relevant drainage authority.

N.B. For more information on works related to piped/culverted ordinary watercourses outside of the drainage board area, please view theSummary of Requirements for

C) Removing gravel

Gravel should not be removed during fish spawning season. Before removing gravel from a watercourse, you should contact the EA for advice.


Environment Agency

Tel: 03708 506 506

Somerset Drainage Board Consortium

Tel: 01278 789906

Lead Local Flood Authority (LLFA) Somerset Council

Tel: 0300 123 2224