Clearing field ditches is a necessary part of managing the water flow on and around your farm. Keeping drain outflows clear and ditches free from debris can help to protect land from flooding, both on your farm and further downstream.
Some operations, for example removal of sediment or dredging a watercourse, will need authorisation from SEPA. However, there are many operations you can do to maintain field drainage systems on your farm by just following the Diffuse Pollution General Binding Rules (DP GBRs). For example:
- removal of sediments, vegetation or debris from a field drain or completely man made ditch
- remove debris and vegetation from a ditch, burn, river, loch and wetland
If you want to remove sediment from a straightened river, burn or ditch that is less than 1m wide, within 5m of a drainage outfall (e.g. from a field drain or septic tank) or within 10m of a closed culvert (e.g. pipe crossing), then you must follow a series of General Binding Rules (based on good practice). The list of measures includes:
- Remove only the sediment caught in the channel, do not over widen or deepen the channel
- Plan vehicle movements to reduce the risk of erosion on the banks and bed of the channel
- Avoid any unnecessary vegetation removal; if removed do not dispose of it into the channel.
- Minimise silt pollution. Work in a downstream direction and where necessary provide additional protection e.g. straw bales or silt fences to trap excess sediments.
- Don’t create any steps or sudden changes in the level of the channel bed. Grade the bed to achieve a consistent level and particularly where the work connects to the upstream and downstream sections.
- Don’t pile up the sediment and raise the height of the banks; removed fine silts and sediments may be spread on the farm if appropriate
Its worth noting that clearing ditches can be damaging to wildlife which rely on these habitats – its best to clear ditches later in the summer (May - October) to avoid the main breeding, spawning and nesting seasons. You can check with the local fishery trust, SNH office or agricultural consultant about the best time to carry out the activities in your area.
For more information, see:
- AHDB Field Drainage Guide
- Technical Note (TN720): Assessment for Land Drainage
- Check, Clean and Dry - a campaign to avoid the spread of invasive, non-native species
- Technical note (TN697): Invasive Plant Species – Japanese Knotweed, Himalayan Balsam,Giant Hogweed and Skunk Cabbage
- Working in or near rivers or lochs
- Registration rules explained: Dredging in straightened river between 1 and 5 m wide
- Registration rules explained: Removal of exposed sediment such as gravel bars
- Silt control guidance - preventing pollution while dredging