To keep the water clean without having to spend time on weekly maintenance of the filtration equipment, a bioplateau was built.
This resulted in an interesting system.
Water from the roof flows through a gutter into a small stream, over which a bridge is built directly from the kitchen porch to the summer terrace. From the stream, water flows into the main pond through a cascade. The bioplateau, planted with higher plants such as iris and loosestrife, purifies the water, which in turn flows into the main pond.