The Borden Park Natural Swimming Pool is
the first chemical-free public outdoor pool to be built in Canada. The project
replaced an existing pool, and includes a seasonal pavilion and landscaped pool
precinct for 400 swimmers. The challenge was to create a large-scale pool with
the high-quality water control while also achieving an environmentally healthy
and natural filtration process. The design process began with developing a pool
technology that cleanses the water through stone, gravel, sand, and botanic
filtering processes. This inspired a materials-oriented concept for the change
room facility to achieve a technically rigorous and aesthetically integrated
design whose gabion stone walls visually evokes the idea of filtration.
Canada’s guidelines for public pools are some of the strictest in the world. To
realise the project the architects needed to take a creative design approach
grounded in a first principles, science-based approach to the design challenge.
The pool involves a balanced ecosystem where plant materials, microorganisms,
and nutrients come together within a gravel and sand filtering process to
create “living water”. Filtration is achieved in two ways: through a
biological-mechanical system or the constructed wetland and gravel filter, and
in situ, with Zooplankton. This is an unsterilized, chemical and disinfectant
free filtering system in which isolating membranes contain water as it
circulates and is cleansed by means of a natural process. The process takes place
at the north end of the pool precinct. On deck, water passes through a sand and
stone submersive pond and a planted hydro botanic pond. Adjacent to these
ponds, a granular filter PO4 adsorption unit is enclosed by the gabion walls
continuous with the building. The seasonal building houses universal change
rooms, showers, washrooms, staff areas and the water filtration mechanisms. The
swimming program includes a children’s pool, a deep pool, on-deck outdoor
showers, a sandy beach, picnic areas, and spaces for other pool related
recreational activities. The project’s materiality creates a fundamental
conceptual connection between the technical demands of the pool and the design
of the built enclosure and landscape elements. The dark locally sourced 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. The gabion walls of the low rectilinear building terminate with a
lid-like flat roof that frames the tree-canopy of the park beyond and enhances
the sensation of opensky spaciousness within the pool precinct. The elemental
form and reductive materials ease the user experience and enriches the
narrative of bathing in the landscape. The juxtaposition of the constructed
elements invokes comparisons with the geology of the North Saskatchewan River and
the flat topography of the prairie lands edge.
CREDITS
Architectural Design: gh3 Architects
Contractor: EllisDon
Statical, Mechanical and Electricity Project: Morrison Hershfield
