Swimming Ponds

Two families in Quebec and B.C. are at the forefront of a move from traditional swimming pools, with their blue tiles and chemically treated water, to ‘natural’ swimming ponds.

Written by: Brian Slemming
Photos by: Michael Bowie

Benate Heidersdorf loves spending summer days in the pond in her Quebec home. Cheryl Hagen is anxiously waiting the time when she can leap into her swimming pond in Chilliwack, British Columbia. But unlike families with above or below-ground pools, these families are swimming in ‘natural’ ponds surrounded by a colourful display of aquatic, oxygenating plants. The Hagen and Heidersdorf families are at the forefront of a move from traditional swimming pools, with their blue tiles and chemically treated water, to ‘natural’ swimming ponds.

There’s something refreshing about swimming in natural water, whether in the sea, a lake, pond or river. Now that experience can become a reality in almost any suburban garden. If your garden is large enough for a traditional pool, it’s large enough for a natural swimming pond.

Natural swimming ponds first appeared in the mid 1980s in Germany and Austria. Since then, they have become increasingly popular in Italy and Spain. Although firm numbers are difficult to verify, it’s speculated that Europe now boasts between 25,000 and 30,000 such facilities. They have been constructed in residential gardens, hotels spas and by municipalities for public swimming. The German municipal facilities are used year-round for summer swimming and winter skating. If ever a recreational facility was designed for hot Canadian summers and cold winters, natural swimming ponds would be high on the list. In the past three years the concept has spread to the U.K., and there are now a handful of companies and architects that is constructing natural swimming ponds in North America.

Paradoxically, ‘natural’ swimming ponds is a misnomer. There is nothing ‘natural’ about them – they are carefully designed and constructed, and many years of experience and technology development have gone into establishing a successful European swimming pond industry.

Although the continual cleaning of the water by the surrounding plants is a naturally occurring event, swimming ponds also use pumps and aeration to improve the performance of the cleaning plants. A well-constructed swimming pond displays no evidence of the plumbing and allows an owner to enjoy all the attributes of a garden pond that is home to a variety of water plants.

Natural swimming ponds are actually one large pond split into two sections by a virtually invisible division, which separates the larger and deeper swimming area and the more shallow vegetative area. This dividing wall extends from the pond bed to between four and 15 inches below the pond’s surface. While the water for both areas is one entity, the two areas can be adjacent to one another, or the planted area can wrap around the swimming area. A circulating pump creates a suction that draws the water from the swimming area down into the gravel bed of the plant area, where it passes through a skimmer. Then the plants take over and the roots take their needed nutrients out of the water. The water is then discharged back into the swimming zone.

To create your own swimming pond, begin with a hole. The sides should be sloped with a one-foot rise for every three feet horizontally. The top of the excavated hole will be the area for planting. It should taper from a depth of 18 inches to two to three inches around the pond’s edge. The two areas – swimming and plants – should be approximately 50/50 in area. This ensures the planted area is capable of cleansing the swimming area.

Lining is the next step. It can be complicated if the pond has unexpected shapes and bumps. The liner must go up the vertical wall that surrounds the swimming area, over the top and down to the bed of the vegetative area. Rubber and PVC liners are most popular.

Once the liner is in place, the bottom should be covered with four to five inches of gravel. The gravel bed in the planting area is a soil mix to form a growing medium for the plants. It also carries the aeration system and the pipes, which when connected to the pump, pull the water down through the roots, forcing the plants to take up the available nutrients and clean the water before the pumping system returns the water to the swimming area.

Renate Heidersdorf is one of Canada’s foremost artists. In addition to running her own gallery, she runs an art school for children and adults in Beaconsfield on the westernmost part of the island of Montreal. Thirteen years ago she and her soon-to-be husband traveled through northern Europe.

“I couldn’t help noticing how many gardens had natural looking ponds in them,” she says. “I said to my future husband, ‘I would really like to have a pond like these.’ We have about a half-acre lot and our swimming pond is 48 feet long by 12 feet wide.”

In the centre, the pond is six feet deep. It was designed and built by fellow artist Sylvain Racine. Rather than sloping the sides, Racine opted to use a series of terraces. The pool is lined and has been operating without any artificial cleaning for five years.

“I just love my pool,” says Heidersdorf. “We have a group of koi in the pond. I swim with them and over the years they have become very friendly and they swim alongside me.”

In Chilliwack, Cheryl and Lucas Hagen are building a new home on their 10-acre farmstead. “On the site there was an old concrete silage pit, which was collapsing, so we decided to clean it out and turn it into a pond,” says Cheryl. “Then Lucas suggested we make it a swimming area.”

Construction costs are as variable as the cost of installing a traditional swimming pool. It depends on size, terrain and complexity. A good rule of thumb is that there is little difference between the cost of a swimming pond and a similar sized traditional pool.

Apart from the aesthetics, the real advantage of the swimming pond is the minimal maintenance required. Pool owners claim that cleaning the pond once a year is sufficient, depending on the surrounding environment and how much debris winds up in the pond. There is no requirement for chlorine or other chemicals, nor is a weekly or monthly cleaning required.

It is as close to lake swimming as one can get without driving to the lake. An added plus is that swimmers have no need to concern themselves with whether the lake is polluted. Keep your plant area healthy and you can dive headfirst into a project that you know is free of pollutants and chemicals, and which will never need emptying and repainting.