The move follows a state government decision to raze the state heritage-listed Thebarton Police Barracks – the current home of the mounted operations unit, also located in the park lands – to make way for the new $3 billion Women’s and Children’s Hospital.

Legislation which passed parliament in November allowed SA Police to select another patch of park lands to build a new barracks.

The protest rally will take place from 11.30am at Mirnu Wirra (Park 21 West or Golden Wattle Park) on the corner of Greenhill Road and Sir Lewis Cohen Avenue, which was announced last month as the proposed new location of SA Police’s mounted operations unit.

The eight-hectare park lands site could cater to 40 police horses, dogs, and include perimeter fencing and ancillary buildings to support the barracks’ operations.

Conservation groups including the SA Conservation Council, Trees for Life, Adelaide Park Lands Association, Butterfly Conservation SA and the Nature Conservation Society of SA argue the park is home to “priceless regenerated bushland”, including a number of rare native flowers and 15 different native plant specifies.

“SAPOL quite literally couldn’t have chosen a worse location from an environmental perspective,” Conservation Council chief executive Craig Wilkins said.

“No one expects SAPOL to know about biodiversity and rare species in the park lands, but the community does have a right to expect a proper assessment before they nominated a site.

“We have no doubt that if SAPOL had been required to undertake normal planning checks and balances, Mirnu Wirra would have been immediately ruled out as an option due to its extraordinary nature values and its significance to the Kaurna community.”

Conservationists fighting the proposal to develop Mirnu Wirra (Park 21 West/Golden Wattle Park). Photo: Angela Skujins/CityMag

Trees for Life volunteer Jan Lawry described Mirnu Wirra as a “special patch of bushland right in the heart of Adelaide”.

“There is so little remnant vegetation left and once it’s gone, we can’t get it back,” she said.

“Volunteers have spent over a thousand hours working here over the years because it’s important to the whole community.”

SA Police Commissioner Grant Stevens has previously said that Mirnu Wirra was chosen as the preferred new mounted barracks site following an extensive evaluation process.

A state government spokesperson told CityMag earlier this month that the park was the “safest” and “most suitable” location for the mounted operations unit.

They said further “detailed design and scoping analysis” was being undertaken for the new mounted operations unit.

“Any activity undertaken during the establishment of the new Mounted Operations Unit facility will seek to minimise the visual and physical impact in the area,” they said.

But former Labor minister Chris Sumner, who served under the Corcoran, Bannon and Arnold governments, told InDaily that the Malinauskas Government was in “flagrant breach” of promises it made before the election regarding the park lands and heritage.

He said since the Dunstan Government in the 1970s, Labor had a policy of trying to reduce developments encroaching on the park lands.

“This is the most egregious attack on the park lands in a decade,” he said.

Adelaide Park Lands Association president Shane Sody accused the government of “six attacks on your park lands in its first year alone”.

He called on the government and SA Police to identify an alternative location for the mounted operations unit.

“There is still time for a rethink, and a chance for the government to belatedly start to love your park lands,” he said.

The state Opposition also criticised the “park lands grab”, with shadow assistant environment and heritage minister Jack Batty accusing the government of hand-balling responsibility for the park lands.

“Labor are treating the Adelaide park lands like a free land bank,” he said.

“The park lands grab underway appears to be happening without consultation with council, local conservation groups, or First Nations people.”

Environment Minister Susan Close told ABC Radio Adelaide earlier this week that she had “no intention of being part of a government that raids the park lands”.

She said the Opposition supported the legislation which allowed SA Police to select a patch of park lands for a new mounted operations unit.

“The bill that went through parliament that was supported through parliament was to create the Women’s and Children’s Hospital and at the same time to say that the horses could go in the park lands,” she said.

“That was subject not only to cabinet debate but also parliamentary debate and I don’t believe was opposed by the Opposition.

“We live in a democracy and while decisions will be contested and people will be angry or disappointed in some ways and highly supportive in others, welcome to a modern democracy.

“Making sensible decisions from time to time is what’s required.”

Asked if she could “see any more of these sensible positions coming our way”, Close responded: “I can’t see any at the moment”.