By Larry Carnes
Ponds built for swimming are becoming more and more popular – at least they have been in our business. For the past 3-4 years, we’ve actively promoted recreation-style or swimming-style ponds and have experienced some strong success. Now more than half of our projects are designed and built with swimming in mind, and many of those installations stand among our finest efforts.
It’s similar in some respects to what we see in the swimming pool market where people are investing in their backyards so they can enjoy the stay-at-home vacation experience. It makes sense for many pond enthusiasts, as well, because if you’re already building a body of water on your property, why not make sure it’s also suitable for swimming and other aquatic pass times?
Building ponds for human immersion requires careful adherence to a handful of key concepts that differ from decorative ponds. If you don’t think about swimming as a primary function, then it is possible to create unnecessary hazards and to miss opportunities to amplify the experience factor.
A BIG EXAMPLE
Swimming ponds are typically larger and deeper than purely decorative ponds and they don’t tend to have as much in the way of aquatic plants and fish. You certainly can have both, but not very many clients are keen on the idea of swimming with fish. Aquatic plants are in almost every pond, but mostly planted along the edges.
Swimming ponds have obvious points of safe entry and egress, water quality is a priority, they are often deep enough for diving and perhaps most important of all, you have to use equipment that is rated for treating and moving water in which humans submerse themselves. All of swimming ponds meet these criteria.
By way of an example, one of my favorite projects we’ve done in recent years, pictured here, involved a large pond on a five-acre upscale property in Highland Park, Ill.
It started out with the homeowner’s desire to recapture an enjoyable part of his youth, much of which revolved around swimming and playing in the water. He cherished the memories of growing up near a large pond by his family’s home in Northbrook, Ill. Years later, with the tear-down/rebuild of his new “forever home” underway, he decided to devote a portion of his property to recapturing the pond life he loved as a kid, while also leaving a legacy of fun and togetherness for his family. That’s when we became involved.
|Indicating where you should get in and out of the water is a top priority in swimming pond design. The beach, deep water and deck all indicate the pond is meant for immersion.|
From our first discussion, it was clear he wanted an aquatic destination, something that functioned more like a small lake than a backyard pond. That’s why it has a beach, why it’s nine feet deep in the middle, and why all of the inner contours meet the specs for a diving envelope. (They were considering anchoring a sunning raft in the middle where you can dive in the deep water, but that has not yet happened.)
The 20,000 square-foot pond is pastoral by design, with wide expanses of partially wooded lawn gently sloping toward the water’s edge. It has 16,000 feet of usable water space, with the remainder in a shallow filter area that features emergent grasses and other plants. It’s shaped like a giant clover, which provides shifting views as you move around the perimeter.
The surface is about 190-by-182 feet at the longest points. On the near side to the house, we located a private, 53-by-23 foot sandy beach.
The beach is where this project says “go swimming here” the loudest. It’s the central destination in the landscape, a perfect place to linger by the water’s edge or wade in for a dip. It’s a place where the clients can pour a cup of coffee and relax on the Adirondack beach chairs, or grab a pair of binoculars and bird watch from a nearby bench.
It’s a situation where all that beautiful daydreaming was built on some heavy lifting. Instead of ramping up the liner to form the beach space, we kept it flat with sculpted shelving. It’s all held in place with a low retaining wall, giving the beach a stable footing.
Hey, It’s Clay!
Contouring and sculpting the inner pond certainly had its challenges. While digging for the mechanical and PVC plumbing installation, the crew uncovered an area comprised of bentonite clay, which extended to a depth of about eight feet. (These are the kinds of surprises we run into, especially on large projects like this one.)
On the surface, the clay area looked like just a rough spot on the bottom of the pond, but we quickly discovered that the 10-by-10 foot area was not drivable with the skid steer, which began to sink into the soil. We laid down crushed stone and gravel to help stiffen the clay, but that didn’t provide much help. Eventually, the space was dug out by machine and filled entirely with crushed stone.
Our liner was then laid over the entire bottom surface of the pond and a big-loader back-filled the area with gravel by conveyor belt. The bottom of the pond and base for the retaining wall were covered within four hours.
The space was backfilled with 240 tons of washed sand, a blend of fine, medium and coarse grain sizes chosen by the homeowner. The sand bed is two-feet deep, suitable for digging sandcastles and burying friends and family members.
It tapers into the water at a 7:1 slope, making it easy to swim away from the beach and easy to wade back out of the water. We used a large wheel loader to push the sand into the pond where we feathered it across the smooth gravel to create a comfortable transition area that’s easy on the feet.
While the beach is the primary and most obvious area where you move in and out of the water, we also placed large flat boulders around much of the perimeter that invite you to the water’s edge and then into the deeper water. The main edge detail everywhere else is a low block wall, which defines the pond’s contours and allows you to neatly bring turf to the water’s edge. Although the wall is not necessarily for access, you can easily step into the shallow water and wade in from most of the shore. The retaining wall also provided definition for the pond’s inner contours and a marking point in planning depth.
Glacial erratic boulders dot the shoreline and shallow areas within the pond, giving it the look of a natural body of water that has been contained at the edges by the wall. The interior surface of this pond is covered with a layer of super smooth glacial fill rocks, which are plentiful in this region. We used different blends so that in the shallow area people aren’t walking over large cobbles, while creating a subtle mosaic effect with the different colors of rock. It looks and feels great.
CLARITY AND COMFORT
Water clarity is extremely important in swimming ponds because you want to be able to see where you’re stepping. Clear water in general creates an inviting sense of comfort and cleanliness. In this case, the pond is a self-contained system with an efficient, 4,000 square-foot filter zone located off to one side, dotted with aquatic plants, all separated from the swimming area by a line of stepping boulders.
The idea of using a combination of microbial colonies and plants to control both harmful bacteria and organic compound levels in the water is nothing new. It’s how nature keeps water clean and if you establish a system based on the same principles, with proper sizing, the right combination of plant along with adequate flow rates and volume, you can achieve amazing water quality.
All of the skimmers are located on one side of the pond, with two subsurface return jets on the other, creating a natural blow across the pond toward the skimmers. We may have actually overdone water treatment because, as it turns out, we’re removing organic compounds so efficiently, it’s actually tough to grow some of the decorative water plants. We’ve wound up having to fertilize them, which although a pain, it’s a small price to pay for superior water quality.
Choosing the right equipment for a swimming pond is crucial for safety. In fact, it’s where these systems are the most like a swimming pool in that everything is external, grounded and bonded. The equipment was installed on the side of the pond opposite the beach, hidden from view among plants and shrubs.
|Water quality is another key concern in all ponds and especially in swimming ponds. This pond includes a large filter area where plants and microbes consume organic compounds and control harmful bacteria.|
This project, although larger than most, is fairly typical of the equipment we use. We have skimmer filters made by Filtrific specifically for pond applications, which we use on all of our projects. From there the water flows into fine filters, which are attached to a six-inch trunk line, which runs all way from the north end of the pond 190 feet to our equipment pad on the south side. There we have two Pentair IntelliFlo pumps that pull water through the skimmers and return it via the jets. Just like in a pool, you can achieve significant energy saving with variable speed drive pumps by dialing in the flow to the most efficient rate.
Basically, with swimming ponds you want to avoid using any equipment that isn’t approved for human immersion. That means we never use submersible pumps in any body of water used for bathing. And, we avoid external pond pumps that are not approved for use in water where people swim.
Today, the serene, pastoral four-season pond is indeed reminiscent of a north woods lake, surrounded by trees and plant life, and providing a home for fish and wildlife. This peaceful place is now enjoyed by at least two generations of the homeowner’s family – and likely more as he recaptures a fond memory and shares it as a legacy with those he loves.
Larry Carnes is owner of Reflection Water Gardens in West Dundee, Ill. He began his career as a student of art and developed an interest in landscaping. He worked for several companies, gaining knowledge in tree care, patio design and installation, and landscape architecture. Now a devoted student of naturalistic watershape design Carnes is driven to perfect his designs, always striving to create ponds and water features that qualify as art.