Ordinary watercourse management
We, as the Lead Local Flood Authority (LLFA) (under Section 23 of Land Drainage Act 1991) are responsible for consenting works that:
- propose any changes to the ordinary watercourse
- alter or obstruct the flow in the watercourse.
You must apply to us for a consent to carry out work, 'Including temporary structures. These may:
- place or alter a structure within an ordinary watercourse, for example dams, weirs, culverts (pipes) or any other structure
- affect the flow or storage or water within an ordinary watercourse
- tend to increase the flood risk in the area.
This is known as Ordinary Watercourse Consent (OWC), or Land Drainage Consent.
The regulation of ordinary watercourses consists of two elements:
- issuing of consents for any changes to ordinary watercourses.
- enforcement action to rectify unlawful and damaging work to a watercourse.
What is an Ordinary Watercourse
An Ordinary Watercourse is any river, stream, brook, ditch, drain, culvert, pipe or any other passage that water flows through. It is not designated as a Main River (as marked on Environment Agency main river map).
It does not have to show on a map to be an ordinary watercourse and usually, it is not.
Is it an ordinary watercourse?
Please contact email@example.com if you unsure whether you are dealing with an ordinary watercourse.
Do I need consent?
If you are unsure if you require consent please contact firstname.lastname@example.org.
If the section of watercourse is classified as a Main River, you will need to contact the Environment Agency for an Environment Agency Environmental Permit.
When do I need to apply?
We must grant consent before any works take place.
We cannot grant consent for works that are complete or are already underway.
Any works carried out without consent may require you to return the watercourse to its original state.
Apply for Ordinary Watercourse consent
To apply for consent you need to complete the application form.
The application is only valid if you submit all relevant documents and associated fees.
There is a charge of £50 per structure, with the total cost depending on the proposed works. You can pay the fees for your application by calling Ruth Haile on 020 8359 3696. We encourage you to send the application first so that we can provide you the exact fee for the application.
Applications should be completed electronically and submitted by email to email@example.com, with the appropriate plans and documents attached.
If you prefer to submit a paper copy, the completed application form and all accompanying plans and documents should be sent to:
Applications for OW Land Drainage Consent
Flood & Water Management
6th Floor - Highways
2 Bristol Avenue
The application must be completed accurately, and all accompanying information needs to be clear. If any information is missing, a decision on your application could be delayed.
Once an application has been validated, we have eight weeks to process it and come to a decision, otherwise the consent is automatically granted.
When the application is being reviewed, we might need further information from you, which you are expected to respond to.
Depending on the location of the site and the proposed work, we may also need to consult other organisations about the application. This consultation process may lead to more questions or queries.
There might be other consents/permits required depending on the nature of the works. These are your responsibility to get. Even if you have planning permission or other consents you may still need consent for works to ordinary watercourses
Consent must be granted before any works are undertaken. If works are carried out without consent, then we may legally require that the watercourse be returned to its original state.
We offer a pre-application service for Ordinary Watercourse Consent. This provides advice about:
- what you need to consider for the proposed works on your site
- the level of detail we need from you, in order for us to confirm the application
There is a charge for this service. If you would like to use this service, please email firstname.lastname@example.org
Can we refuse consent?
- We deem that the culverting or the structure being applied for is not necessary.
- A watercourse’s flow will be obstructed: or
- There is insufficient information contained within the application.
- Tends to increase the flood risk in the area.
You should read the guidance notes and ensure that you provide enough detail.
If you are unclear, please contact us on email@example.com before you send in the application.
When we carry out enforcement
We will carry out enforcement action if:
- work has been carried out without permission
- a watercourse has not been maintained and could cause a flood risk
- work has been carried out without permission, and consent has been sought afterwards.
If you notice works to an ordinary watercourse, please contact us to determine whether the works need consent and whether an application has been made.
Things to remember when carrying out works
- If you are going to carry out any works near or within an ordinary watercourse (particularly within 5m), contact us first to find out if you need consent.
- Do not dump rubbish into ditches as this may end up blocking trash screens.
- Do not sweep rubbish and leaves into gullies/drains, this blocks them. Report blocked drain/gully. (linked to Report blocked Gully).
- If any construction works are ongoing, ensure that the materials are stored appropriately. Inappropriate storage of construction materials can block the gullies or nearby watercourses/ditches.
Culverting can exacerbate the risk of flooding and increase the maintenance requirements for a watercourse. It also destroys wildlife habitats. Hence, London Borough of Barnet discourage culverting and only considers it, if alternative options have been explored and there is no reasonably practical solution.
Buildings should not be sited over the top of new or existing culverts/ordinary watercourses. We would oppose planning consent for any building over a culvert as the culvert may, in the future, need to be repaired, replaced or up-rated if conditions in the catchment change. There is also the need to maintain an overland flow route if the culvert is blocked or its capacity exceeded. Please refer Building regulations-Appendix H for the distance from which a watercourse or sewer should be laid from new foundations.
Are you polluting Barnet's waterways?
Help to reduce river pollution and contaminated sewage flooding in Barnet.
Our "are you polluting Barnet's rivers?" information sheet explains how you can help: