Maintenance of open and culverted watercourses

Through the undertaking of regular maintenance works the Agency seeks to ensure the free flow of water in designated watercourses. This is necessary to alleviate flooding and to assist land drainage. In open watercourses the works include clearing silt and gravel deposits which build up naturally in the channel and can restrict the flow of water. Debris such as fallen trees which can lead to blockages in watercourse channels is removed.

Some watercourses are piped under towns and cities, and these are known as culverts. There is a substantial network of these, and many are aged and in need of attention. This is addressed by means of a comprehensive inspection and survey programme to assess their structural condition. The Agency carries out maintenance work along the lengths of these culverts, and at their inlets where metal screens, known as grilles, are often located to prevent debris entering them. These are regularly inspected and offending debris is removed.

The Agency undertakes a rolling programme of planned inspection of designated watercourses to identify where maintenance work is required. From this information a programme of maintenance is compiled and published annually. However, maintenance needs can be unpredictable, and works frequently require to be re-prioritised.