Description:
The Borden Park Natural Swimming Pool (NSP) is the first chemical–free public outdoor pool to be built in Canada. The NSP replaces an existing pool built in the 1950s with a seasonal pavilion and landscaped pool precinct for the activities of 400 swimmers. At the NSP, the challenge of water quality control, essential to any public bathing facility, is compounded by the scale and the technical demands required to achieve an environmentally healthy and natural filtration process. gh3* married the technologies that cleanse water through stone, gravel, sand, and botanic filtering processes with a materials-oriented concept to achieve a rigorous technically and aesthetically integrated design.
At the NSP, the fundamental conceptual connection between the technical demands and the design is realized through relationships between the materiality of built enclosure and the landscape elements. The dark limestone and steel of the gabion wall construction defines the enclosure’s vertical dimension as filter-like or breathable, as granular and porous. The pool precinct is defined by a planar landscape where flush to surface detailing creates seamless interfaces among sandy beach, the concrete pool perimeter and wood decking. [1]
From the exterior gabion walls to the interior concrete floors and sinks, the most important material in the project is stone. “Everything is built on the idea of stone in its incremental forms,” says architect Pat Hanson, FRAIC. “When you think about clean water, you think about mountain water—water rolling over rocks and this relationship of cleanliness and hard mineralized surfaces.”
To preserve the integrity of the water, showers are mandatory. After soaking under sleek, cane-shaped on-deck showerheads, we enter the wading pool. The water has a soft quality to it, similar to a lake, and is perfectly cool on this blazing hot day. This natural, clean water is as much an achievement as the building itself, and as my infant son dips into it, I am glad for the designers’ efforts.
Swimming pools in Canada have typically been rendered safe through the use of harsh chemicals like chlorine. This sterilizing comes at the cost of red eyes and bleach-scented skin. The Borden Park Pool water is different. Before city-supplied water enters the closed loop system, it is dechlorinated and phosphates are removed. From the pool, water is continuously filtered through a three-chamber sedimentation system that removes large particles. It can then go one of two ways. In one direction, it gets sprayed onto specially selected aquatic plants at the top of a large Neptune sand filter. The plants remove microorganisms by absorbing them as nutrients. The water slowly filters through layers of granite rocks, which catch smaller dirt particles and microscopic impurities. The other pathway leads to the on-deck filtration system consisting of a sand-and-stone submersive pond and planted hydrobotanic pond. After travelling to a holding basin, the water can then move to heating, a UV purifier, and another phosphorous absorber. Rather than being sterile, this water is living and clean.
To operate this Canadian-first-of-its-kind pool, Borden Natural Swimming Pool was classified as “recreational waters,” like a lake. “In the end, we applied for the building permit as a ‘constructed beach with variances’. And the variances were the pools,” Hanson explains. “We had the potential to back up the system with chlorine if it didn’t work. And it has worked out, but it was a bit of a calculated risk.” [2]
Awards
2021 Civic Trust International Award
2020 Governor General’s Medal in Architecture
2020 OAA Design Excellence Award
2020 Fast Company World’s Most Innovative Companies In Architecture
2019 RAIC Award of Excellence for Innovation in Architecture
2019 City of Edmonton Urban Design Award of Excellence
2014 Canadian Architect Award of Excellence
References:
[1] Giacomo, Joel Di. “Borden Park Natural Swimming Pool.” gh3*. gh3*, February 10, 2021. https://www.gh3.ca/work/natural-swimming-pool-02.
[2] Dovell, Cynthia. “Master Stroke: Borden Park Natural Swimming POOL, Edmonton, Alberta.” Canadian Architect, May 2, 2019. https://www.canadianarchitect.com/master-stroke-borden-park-swimming-pool/.
Additional information:
“Borden Natural Swimming Pool.” Borden Natural Swimming Pool | City of Edmonton. Accessed August 24, 2021. https://www.edmonton.ca/activities_parks_recreation/borden-park-outdoor-pool.
Borden Park Natural Swimming Pool. Vimeo, 2021. https://vimeo.com/363589470.
Gonchar, Joann. “Borden Park Natural Swimming Pool By gh3 Architecture.” Architectural Record RSS. Architectural Record, August 21, 2019. https://www.architecturalrecord.com/articles/14194-borden-park-natural-swimming-pool-by-gh3-architecture.
Klein, Kristine. “GH3 Designs Naturally Filtered Outdoor Swimming Pool for CANADIAN PARK.” Dezeen, August 31, 2020. https://www.dezeen.com/2019/08/20/borden-park-natural-swimming-pool-gh3-edmonton-canada/.
Luco, Andreas. “Borden Park Natural Swimming Pool / GH3.” ArchDaily. ArchDaily, August 23, 2019. https://www.archdaily.com/923434/borden-park-natural-swimming-pool-gh3.
