Ditches play an important role on farms as part of its drainage network. Land drainage systems are designed to flow into these watercourses and efficient drainage is essential to productive farming. They prevent surrounding arable land from becoming wet, helping to improve the structure of the soil to enable better yields. To operate efficiently, drainage water must flow freely down a gradient to carry the water away from fields.
How much maintenance will depend upon how quickly silt and tree debris is built up in a ditch and their actual drainage function. For example, artificial ditches are created by farms to support their drainage network. These ditches will require much more regular maintenance than natural watercourses to enable them to function efficiently and to maintain their wildlife interest.
The best time to undertake ditch maintenance work is in the autumn and winter months, as this will limit the impact on wildlife. It is also a quieter period for farms, enabling them to dedicate more time to this task.
Periodic cutting or clearing in artificial ditches is recommended as it can help avoid the need for drastic work in future years as well as help maintain a diverse range of conditions for wildlife. Problems arise when ditches are not maintained and then when drains start backing up, farms can react by cleaning out or reprofiling their ditches in the hope that it will improve the efficiency of their drains. But such reactive and insensitive deepening and widening of banks can, unfortunately, lead to damage to wildlife.
They also recommend that ditches are maintained on a rotational basis leaving 30-50% of vegetation undisturbed, working short sections on alternate banks to minimise damage, maintain continuity and leave undisturbed areas as a source for recolonisation. Rotational clearing of only part of ditches on a less regular basis will also encourage settling out of sediments and recycling of nutrients through uptake by stream vegetation such as reeds and rushes.
It is also important to maintain drain outflows and the watercourses or ditches these flow into. These can become blocked with tree debris and silt build-up so it is important they are regularly clearer.
