Australian architects MJA Studio have proposed a novel way of saving a much-loved sports stadium facing demolition: by turning it into an enormous outdoor wave pool.

The future of the 43,500 capacity Oval stadium in the Perth suburb of Subiaco is unclear, as it is due to be replaced as the region’s main Australian Football League (AFL) venue by 2018. The local council has called for suggestions from the community to save the space and revive a community also reeling from the closure of two historic public markets.

MJA say they are determined to reverse Subiaco’s slow decline by transforming the site into a mixed-use public space with a lagoon at its heart providing “the highest-quality man-made waves on the planet, and the most authentic surfing experience”.

In a statement, the architects said: “Our proposal took the form of a schematic proposal based around the principles of inclusivity, expanded public space and access, accessibility, recreation and recognition of heritage.”

To realise the design, the walls of the stadium would be demolished, crushed and re-used in the construction of the pool and the creation of a new 12,800sq m (137,800sq ft) public space. This elevated area – designated for sports, recreation and leisure activities – would extend into the surrounding park and follow the geometry of the stadium. A 3,000sq m (32,300sq ft) permanent marketplace and a new Football Hall of fame would pay tribute to the region’s cultural heritage.

The firm say the project is environmentally sustainable. In addition to the use of recycled materials, the water required to fill the pool for 50 weeks throughout the year would be the same amount as is currently used to water the stadium’s pitch.

A decision on the fate of the Subiaco Oval has not yet been made. Its replacement as the home of AFL teams the West Coast Eagles and Fremantle Football Club is the new 60,000 capacity, AU$1bn (€706m, US$795m, £508m) Perth Stadium currently being constructed in the city’s Burswood district. That development has been designed by Cox Architecture, design studio Hassell and architects HKS Sports and Entertainment Group.

Meanwhile, Perth residents eager for an outdoor swim can visit Australia’s first pop-up waterpark, Xscape at the City, which will arrive at the city's Belmont Park Racecourse this month. Designed and operated by Australia-based Amusement Leisure Consultants, the attraction's premier feature is a fully demountable balloon/air slide – the tallest waterslide in the world in its class.