Zwemvijvers

Zwemvijvers are man-made bodies of open water designed for recreational swimming and rely on natural processes to maintain water quality rather than chemical disinfectants. They usually include a swimming area and a regeneration or filtration zone planted with aquatic vegetation. Water is circulated through a biofiltration bed and plant roots, where microbes and plants remove nutrients and pollutants, creating a clear, safe swimming environment with a natural appearance.

In typical constructions, the swim zone is separated from or connected to a planted regeneration zone by a barrier or depth changes. A pump circulates water from the swim area through gravel or sand filters and macrophyte beds before returning it to the swimming basin. The balance of plants, substrate, and circulation governs clarity and ecological health.

Zwemvijvers gained popularity in the Netherlands and wider Europe from the late 20th century as an alternative to chlorine-treated pools. They are found in public parks, resorts, and private gardens, valued for lower ongoing chemical costs, biodiversity benefits, and a more natural aesthetic. They require specialized maintenance, including plant management, sediment control, and monitoring of water quality.

Regulation and safety vary by jurisdiction. In many regions, bathing water is subject to quality standards and seasonal monitoring, with advisories or closures if indicators exceed limits. Public zwembijvers typically implement safety measures such as fencing, depth markers, and, where appropriate, lifeguards.