Suburban Perth has a big shortage of playing fields that could have long-lasting physical and social consequences, a landmark study into public space in WA reveals.
The government-funded study by Curtin University sport, recreation and urban planning experts concludes Perth needs another 51.6ha of open space to meet the needs of the population.
This equates to 23 Australian Rules ovals or 72 soccer pitches.
Unless action is taken, the report predicts the shortfall could blow out to 510ha by 2031 - including 165ha, or 75 AFL ovals, of playing space and the remainder in support facilities such as clubrooms.
A report author, Curtin University Associate Professor Garry Middle, said declining public space in the past two decades was an unintended consequence of environmental and planning policies.
Green space - traditionally used for recreation, organised sports and outdoor play - was also being used for environmental protection, water management and catchments.
New suburbs did not cater to the need for sporting ovals and facilities but favoured "passive use" spaces such as small parks.
"Without a change to the relevant planning policies and without the State Government stepping in to provide additional active open space, this shortage can only get worse," Professor Middle said.
The study examined 139 suburbs and found the percentage of green space dedicated to active recreation varied between 6.24 per cent and 15 per cent across four subregions.
Passive recreation areas accounted for most green spaces the report authors mapped.
The situation in the South West corridor - including Cockburn, Kwinana and Rockingham - was deemed "unsustainable", with half of the grounds in the study area heavily used because neighbouring areas did not have any. This forced residents in those areas to travel much further to playing fields in older established suburbs.
Nature Play WA chief executive Griffin Longley said the findings confirmed that dwindling public space was becoming a significant concern, particularly with almost a quarter of WA children overweight.
"The cost of having a disconnected, unhealthy population far outweighs the cost of increasing public open space," he said. "The biggest contribution of playing fields is social cohesion.
"There's no other way families of diverse backgrounds get together to communicate, co-operate and understand each other."
Mr Longley said smaller WA blocks with less backyard play space compounded the situation.
Professor Middle recommended looking at making school ovals available for joint use and big enough for senior sports.
Acting Sport and Recreation Minister Terry Redman said a working group developing a guide to sharing school facilities was to report in the first half of this year.
He said the report was commissioned to establish benchmarks and guide policy on the provision of public open space.
North Perth mother Deborah Lisk said her local park, Charles Veryard Reserve, was like a big backyard for her sons Hamish and Caleb.
"We don't have a backyard, like people used to in the old days, so we spend so much time at the park," she said.
"The boys are always playing soccer, cricket or footy there.
"We'd be lost without it."