St Peters Billabong Deputation

by Mathew Pole to Norwood, Payneham & St Peters Council on Monday 3rd June 2024

Good evening!

I am dismayed by the lack of debate in response to the questions raised by Councillor Moorhouse. Ms Mara also wrote a letter to Jack Batty, member for Bragg on the 15th May. What I found interesting are the omissions in the responses by Ms Mara. I implore councillors to pay close attention as I outline these matters concerning a 20, 30 or more million dollar problem.


The St Peters Billabong is the largest community reserve in the council and is classified as ‘regional open space’. The park is zoned as part of the Linear Park (River Torrens). It is home to many species of native flora and fauna.

Since starting the petition, I have spoken with people of differing viewpoints. leading to more questions than answers. Tonight I will ask some of the most pressing questions.

In 2018, Barrister Ralph Bleechmore, a former St Peters councillor, Vietnam War Veteran and formerly active member of the Friends of the Billabong raised concerns with council about encroachment by houses along the top of the billabong. Thanks to Ralph’s efforts through Freedom of Information requests, 4 reports were released by the council. Reading the agenda tonight I note that it quotes from an unreleased Golder 2020 report. Why has this not been released to Mr Bleechmore?

Stability of the Bank

The stability of the bank has been a known issue for many decades. In September 1955, The Advertiser featured a photo of the river bank collapsing. The Coffey Report understands the main reason for 1970s diversion of the River Torrens was concern about erosion caused by the river. I would argue that the stability of the bank should be of concern to an ordinary man.

In 2000 the Coffey Report stated that properties from 12 Eighth Avenue to 17 River St were at risk of being affected by slope instability. At the time their “judgement was that existing houses are unlikely to be affected by slope instability in the next 50 years”. Since that statement, the profile of the street has changed dramatically. In approximately 2005 a new dwelling was constructed at the rear of 13 River St within metres of the top of the bank. From 2011 onwards, dwellings from 5 River St to 11 River St have been constructed. Each of these dwellings are significantly larger and closer to the edge of the bank.

  • On what basis did council staff approve these developments when according to the Development Plan 2021, “no development could be undertaken within sixty metres of either side of the boundaries of the River Torrens’?
  • Did the council staff consider the findings of the Coffey Report (2000) that these ‘properties are at risk of being affected by slope instability’ and that permitting construction of homes significantly closer to the unstable edge would increase the risk?
  • Did the council provide the Coffey Report to property owners? If not, has the council created liability by withholding prior knowledge?
  • Do owners bear any responsibility, If shown to have encroached on council land, removed vegetation or planted lawn and other inappropriate vegetation?


Ms Mara’s letter to MP Jack Batty acknowledges that encroachment has occurred, but does not discuss larger more recent encroachments. Council sold 3 River St in August 1980. Aerial photography by NearMap shows 5 River St extended their fence on to council reserve in 2010 and further extended the fence in 2021. These are the properties of most concern.

The solution proposed by Ms Mara is to ‘resolve the encroachments by boundary realignment and licences/leases to occupy the land’. The question I would like to ask is:

  • ‘Does council have the authority to do this?’

The ‘Parks and Reserves Community Land Management Plan states the only authorised exclusive use is ‘provision of publicly accessible electric vehicle charging stations’.

The St Peters River Park is subject to the Linear Park Act 2006 which requires a resolution passed by both Houses of Parliament to vary, sell or otherwise dispose of land included in a linear park.

The second question I would ask is:

  • What precedent does this set?

Engineering Solutions

The Coffey report lists as an option to ‘do nothing’ as cliff retreat is a natural process and comments that ‘people may be more tolerant to risks from natural slopes than from engineered slopes.’

In 2021, Golder estimated the costs as up to $7 million using Rawlinson’s Construction Cost Guide 2018. Based on cost blowouts in the Payneham Memorial Swimming Pool from $20 million to $60 million and the George Street upgrade from $800 thousand to $2.3 million, today that could easily be $21 million or more. Excluded from the Golder estimates are many costs including purchase of private property, demolition and site access constraints.

  • The business case for the $100,000 invasive geotechnical survey states the purpose is to identify viable and economic solutions. Has the council set a limit on the dollar value per house that is acceptable?
    $21 million would be $1.4 million per house.
  • By approving developments in the past 20 years, has the council limited the available options and increased the cost?
  • If the council proceeds with an engineering solution is this creating further risk to the council along the entire length of the RIiver Torrens?


Thank you councillors for accepting the petition and granting me time to speak this evening. The St Peters River Park is a treasure that many enjoy. I hope that you will consider the reluctance of council staff to provide information and seek answers to the questions raised tonight.

Some of you may know that I am a committee member of the St Peters Residents Association. SPRA have discussed with council some of the issues I have raised tonight, however this evening I have spoken in a private capacity.

Additional Reading


The Mayor did comment that council practice is that discussion does not occur after questions on notice. This does seem interesting.

It is disappointing that the Council Minutes do not record the content of the deputation.