Main Rivers and Critical Ordinary Watercourses are those watercourses that have been classified as such on maps produced and held by the Environment Agency. Critical Ordinary Watercourses are usually large streams, but can include smaller watercourses of strategic drainage importance. This classification of Main River and Critical Ordinary Watercourse includes any structure or appliance for controlling or regulating the flow of water, situated in its channel or along its banks. Main Rivers and Critical Ordinary Watercourses are specifically classified, as they are critical to the surface water drainage of an area.
Responsibilities in relation to main rivers
The Environment Agency has powers, rights and responsibilities under the Water Resources Act 1991, in respect to main rivers, as well as regulatory powers, which can affect people living on or near such watercourses. This is to ensure main rivers continue to operate at their maximum capacity and remain healthy. The Environment Agency carries out maintenance works to manage flood risk, whilst preventing pollution, controlling abstractions and enhancing the environment wherever possible. The main rivers that flow through the Arun District are illustrated on the Environment Agency website Whats in your backdoor? page .
Responsibilities in relation to Critical Ordinary Watercourses
Critical Ordinary Watercourses are maintained by the Environment Agency, in a similar way to Main Rivers. In recent years the Environment Agency have stopped using the term 'Critical Ordinary Watercourse' as these watercourses are now incorporated into the definition of 'Main River'. They are illustrated on the Environment Agency website Whats in your backdoor? page.
Planned maintenance works on main rivers in the Arun District
The Environment Agency has created a web page that sets out the programme of maintenance works for Main Rivers and Critical Ordinary Watercourses in the Arun District, enabling you to find out when works will be carried out. If however you have concerns that works are required sooner than programmed you can contact the Environment Agency's Operations Delivery Team for this region (Solent and South Downs), especially where you may have observed blockages, etc.
Living near a Main River or Critical Ordinary Watercourse
If you live near a Main River or Critical Ordinary Watercourse, you are expected to carry out general physical maintenance of the watercourse to discharge your riparian responsibilities. You should refer to the 'landowner's guide to watercourse maintenance' for advice.
You will require consents from the Environment Agency (and possibly planning permission from Arun District Council) for:
- Building, replacing, altering or repairing anything within 8 metres of the non-tidal part of the river, or 15 metres of the tidal river;
- Diverting or containing the river itself or river flood water;
- Any work to the river bank;
- Any work to tidal flood defences.
If you own, or are buying a property adjacent to a Main River or Critical Ordinary Watercourse, please refer to the Environment Agency's website, which contains advice for riverside property owners. You should discuss your plans for any of the above works with both the Environment Agency's local development and flood risk or planning liaison team and Arun District Council's engineers via firstname.lastname@example.org