Mowing watercourses
Aquatic plants are important for water quality. They hold soil, absorb light and nutrients and provide shelter for amphibians, insects and fish. But too many aquatic plants that take root in the soil and grow to the water's surface can impede the flow of ditches. To reduce water flooding and water shortage (during droughts), we cut aquatic plants and reeds from our 6,000 kilometers of ditches.
How is mowing done?
During the work, we adhere to the "Code of Conduct for Appropriate Management and Maintenance for Water Boards. In this way we take protected animal and plant species into account. Where there is enough room for flow, we leave as many plants as possible. Mowing is done from the shore with a crane or tractor. In wider water, the mowing boat comes along. About 25% of the aquatic plants remain for biodiversity. The clippings are left on the shore for at least two days so that aquatic animals can return to the water. In the urban area we clear away the clippings; in the rural area they remain as much as possible. We mow reeds in phases; annually about one third of the total reed banks. Mowed reed is always cleared away.
When will mowing take place?
From June 15 to July 15 we mow in urban areas; from July 15 to August 1 in rural areas. This leaves about 25% of the aquatic plants on one side of the ditch. This is because there are animals hiding among the water plants that we want to disturb as little as possible. In September/October is the second round of mowing. Then we mow the other side of the ditch only at the locations where it is necessary for the flow. Because Hollands Noorderkwartier is a large area, it is difficult to say in advance exactly where the contractors are working. A tip for individuals with a pump in the ditch is to remove it from the water or mark it with a pole so the driver can take this into account.
