Natural pools – a water-friendly alternative

The installation of natural pools or ponds is an exciting lifestyle trend in landscapes, home gardens and public spaces. A natural pool is a type of constructed wetland that is implemented to purify and store water safely and effectively.

Atypical residential swimming pool can hold anything from 20 000 to 80 000 litres of water. On the Highveld, a pool can lose up to 2 m of water a year from evaporation, while in hotter, more arid regions up to 3.5 m of water can be lost.

Natural pools are eco-friendly and do not require the use of chemicals. Integrated into the surrounding environment, they act as mini-ecosystems and can provide a habitat to a number of aquatic plants and animals. Besides providing an opportunity for the swimmer to indulge in pure, chemical-free dips, the natural pool can become a beautiful feature of any contemporary garden.

Using the concept of wetland or river ecosystems, natural pools use indigenous aquatic vegetation and simple filtration systems to clean the water. Beneficial microorganisms are inoculated into the filter system to break down waste, which is then absorbed by the roots of the aquatic plants. As a result, there are no food sources to facilitate the growth of algae.

The natural system working around and, in the pond, consists of different filtering layers. There is a top wetland area – a large, raised plant box next to the pond which is filled with bog plants in a substrate of coarse bark and a thick layer of gravel. The stone and bark act as an anchor medium for the plants that create a habitat for the microorganisms that break down pollutants, while the gravel acts as a natural filter.

Water is continuously circulated and pushed through this wetland area over a small waterfall, which aids oxygenation, into a lower wetland zone, a beautiful water-lily pond apart from, but adjacent to, the actual swimming area. The water is sucked through the water lilies, another regeneration zone, which clears it of further impurities before it is circulated back into the swimming area.

Natural ponds provide a number of benefits, such as: • providing a habitat for aquatic birds and animals • extended storage of water for irrigation • low cost due to low maintenance and operational costs • removal of chemicals and heavy metals from water. Maintenance of natural pools is easy – simply clearing the filter of leaves and other debris and pruning the natural vegetation once a month is enough to successfully maintain a functioning natural pool.

To reduce the costs of filling the pool with potable water, as one does with conventional pools, the efficient filtering and cleansing that occurs in a natural pool means that rainwater can be harvested to supply the pool. By using harvested water and solar-powered filter systems, a natural pool can be taken ‘off the grid’.