Safer and cleaner, with more nature and lower costs
Flows in streams and other water courses such as locks and canals have to be kept unblocked so that rainwater is drained effectively and incoming water flows to the right place, preventing flooding and safeguarding water supplies. However, large amounts of vegetation can interfere with water flows. In general, water authorities in the Netherlands outsource mowing work on their watercourses and draw up specifications on the basis of visual and local inspections. But removing all vegetation has an adverse effect on nature, runs counter to the Dutch Flora and Fauna Act and doesn't help to achieve the objectives of the Water Framework Directive. In addition, a more targeted approach – that sometimes actually costs less – will achieve the same, or even better, results in terms of hydraulics and ecology.
The aim of the Dotter project, which began early this year, is to help water managers to implement mowing strategies. In that way, good incoming and outgoing flows are guaranteed without unnecessary ecological damage in and around the water. A full-spectrum camera mounted on a drone or boat is used to make complete images of watercourses. The camera uses the reflection of visible and invisible light to distinguish between vegetation and other elements such as open water and shoring.