Borden Park Natural Swimming Pool #2
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.
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 open–sky spaciousness within the pool precinct. At the discrete level of user experience the elemental treatment of form and materials enables ease of movement through functional aspects of the building while it enriches the narrative experience of moving through the bathing landscape. 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 juxtaposition of the constructed elements invokes comparisons with the geology of the North Saskatchewan River and the flat topography of the prairie lands edge.
The rigor brought to a seasonal architecture enclosing family change rooms, showers, washrooms, staff areas and the water filtration mechanisms takes a cue from the two mid–century modernist style pool buildings that remain on site. Built in the 1950s, these extant buildings define the southwest edge of the pool precinct and connect the new to a century old cultural heritage.
NSP is a balanced ecosystem where plant materials, microorganisms, and nutrients come together within a gravel and sand filtering process to create living water. 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, which takes place at the north end of the pool precinct. On deck, water passes through a sand and stone submersive pond and a planted hydrobotanic pond. Adjacent to these ponds, a granular filter PO4 adsorption unit is enclosed by the gabion walls continuous with the building. There is no soil involved in this process. Filtration is achieved in two ways: by means of a biological–mechanical system or the constructed wetland and gravel filter, and in–situ, with zooplankton.
The Borden Park Natural Swimming Pool is indicative of the City of Edmonton’s exemplary leadership and recognition of the civic importance of architectural excellence in the building of public infrastructure. Borden Park has evolved over the last century as a place of shared outdoor recreational activities, as a destination for family gatherings, for outdoor bathing since 1924, as well playing host to a zoo and at times fairground events. Borden Park holds immense civic value and social significance for the surrounding communities and for North–East Edmonton. The NSP contributes a signature landmark element within the on–going transformations of the historic landscape of the Park.
Client: City of Edmonton
Location: Edmonton AB
gh3* Team: Pat Hanson, Raymond Chow, John McKenna, DaeHee Kim, Joel Di Giacomo, Bernard Jin, Nicholas Callies
2014 Canadian Architect Award of Excellence