Arun

The information below provides some helpful 'best practice' information to guide you in carrying out maintenance along your watercourse:

Determine Maintenance Programme 

For all watercourses it is good practice to develop a program that sets out how often you will carry out maintenance works. Most watercourses require annual maintenance to some degree and the best time to undertake works is in late September in preparation for increased winter flows, also at this time, vegetation naturally begins to die back and wildlife is less active and should not be nesting / breeding.

Along open watercourses, your program should state how much vegetation you plan to cut back to ensure a free-flowing watercourse. It should also identify at what intervals you will remove silt from the bed of the watercourse to keep a constant, full capacity channel and ensure that connecting pipes are able to discharge freely.

Along culverted watercourses, your program should inspect the culvert for blockages or signs of collapse. If such problems are identified before a total obstruction to the watercourse occurs, it reduces the likelihood of flooding incidents. Many drainage companies will undertake jet cleaning or camera surveys within culverts at cost, or the landowner can rod their culverts to check for blockages.

Trash / weed screens and grilles should regularly be checked all year round, but, especially at times of anticipated high flow. Debris should be removed as soon as it starts to build up on them.

Ditch in need of maintenance

The right tools for the job

This depends on the scale of your watercourse and the extent of works required. For landowners, maintenance of watercourses is generally best achieved using hand tools, as this is less destructive to habitats, vegetation and the bed of the watercourse. It is far better to undertake minor works more regularly that remove clear obstructions to flow, than completely remove all vegetation and silt from the bed and banks of a watercourse in one go. Regular, minor works will leave healthy vegetation along the bed and banks of the watercourse. This is of importance to the water quality and the wildlife that lives in the watercourse. Of course, if the watercourse has not been maintained for a long time then there may be no option but to undertake major works.

Machinery can clear large stretches of open ditch quickly. If using such machinery, the sensitiveness of the watercourse must be considered and maintenance should be planned to ensure stretches of habitat are left intact (potentially by strimming alternative banks or lengths of a watercourse each year).

For culverts, specialist tools may be needed to jet clean or rod the culvert to clear blockages or to carry out inspections using camera surveys. For culverts or open watercourses many landowners will appoint drainage companies / contractors to carry out maintenance, and the Council recommends that landowners who choose to do this always obtain a range of quotes in attempt to achieve best value.

Ditch cleared and awaiting regrading / desilting

Considering the environment

Watercourses form very important habitats and may contain protected species of flora and fauna protected under the Wildlife and Countryside Act. Various methods for lessening the impact of maintenance works on the environment have been suggested above, such as using hand tools to remove clear obstructions to water, rather than completely denuding a ditch of vegetation using machinery. Also, through careful maintenance planning, alternative stretches of a watercourse can be worked on each year, to ensure there is always a healthy vegetated area where wildlife disturbed by maintenance can migrate to. It must be remembered however, that there must always be a clear free flow to water at all times.

Most landowners will be aware if their watercourse contains protected species. Other opportunities for improving watercourse habitats are also promoted. If you believe water voles are present in your watercourse, you should get in touch for advice. Alternatively, the Sussex Otters Rivers Project has produced a leaflet that sets out wildlife friendly weed clearance and vegetation management in watercourses, which forms a really helpful guide.

Many Farmers take part in Wildlife Stewardship schemes, which set clear rules for the maintenance of watercourses. If these are not adhered to, landowners risk breaking the rules of such agreements and may be penalized.

Preventing problems downstream

Whenever undertaking maintenance works to watercourses, landowners should ensure that any vegetation, debris or silt that has been removed from the watercourse does not end up back in the flow of the watercourse. Care should also be taken to ensure that any disturbed debris does not end up flowing downstream and causing problems for other landowners.  It is recommended that any waste produced from the maintenance of a watercourse be left on the top bank of the watercourse for a few days to allow any organisms within the waste to migrate back into the watercourse. Following this, silt should be spread onto the adjacent land and all non organic waste should be completely removed off site and disposed of in an appropraite manner.

Health and Safety

Watercourses, whether culverted or open pose a range of health and safety risks. Whenever undertaking works along or adjacent to a watercourse, landowners must risk assess their works to ensure they can be undertaken without putting themselves at any kind of risk. Due to the range of watercourses it is impossible to point out all the potential hazards and therefore landowners are required to assess this on a case-by-case basis.

Staying legal

Whenever carrying out maintenance to watercourses, it is down to the landowner to ensure that the works they undertake are legal. General maintenance to a watercourse is unlikely to break the law, but if you alter the watercourse in any way, or build near it without the permission of the Environment Agency, Arun District Council, West Sussex County Council and relevant landowners, you may be breaking the law. Therefore please always speak to the relevant organisations to prevent this situation occuring.

Landowners who are covered by countryside stewardship schemes must ensure that any maintenance works are in line with their agreements. If protected species have been recorded in your watercourse you must also ensure their habitats are not totally destroyed, bearing in mind that you must ensure freeflow of water in the watercourse that you are responsible for.