Auditor General investigating Brown Hill Creek and Keswick Creek stormwater scheme

AN Adelaide stormwater project designed to protect thousands of homes from a catastrophic flood is at the centre of a government spending watchdog investigation into alleged mismanagement.

AN Adelaide stormwater project designed to protect thousands of homes from a catastrophic flood is at the centre of a government spending watchdog investigation into alleged mismanagement.

The Auditor General’s Department inquiry is “examining” the $154 million Brown Hill and Keswick Creeks stormwater scheme almost a decade after it was launched.

The inquiry, which has embroiled five metropolitan councils, is investigating a series of issues related to management, cost and whether it poses risk to ratepayers.

The disclosures prompted residents against the project call for all work related to the project cease while the inquiry into the “fiasco” is completed.

It comes as residents consider launching a class action amid claims of negligence. They have consulted lawyers involved in the Wivenhoe Dam crisis in Queensland.

Since 2006, West Torrens, Unley, Burnside, Mitcham and Adelaide City councils have been investigating how to protect up to 7000 homes from a one-in-100-year flood. Ratepayers face a $154 million bill for the flood mitigation plan to be managed by a subsidiary department. That has yet to occur. At least eight independent engineering reports have been commissioned, which recommend building a dam in the Adelaide foothills.

A plan to build a 12m-high retention structure in the Adelaide foothills was scrapped in 2012, amid a public backlash – led by the No Dam in Brownhill Creek Community Action Group. A new plan was then prepared proposing widening Brown Hill Creek through private properties across a swath of the southern suburbs to avoid major flooding.

A public consultation on that plan closed on Tuesday.

Some residents are concerned about the impact on their homes. The Auditor General’s inquiry was launched in late March to determine whether it is “being managed efficiently and cost-effectively” in relation to its governance, administration and finances.

In a letter to the councils, former Auditor General Simon O’Neill outlined its scope. The investigation centres on whether there have been any “significant” delays in creating the regional subsidiary, what legal advice was sought and any major “concerns or difficulties” in progressing the project.

The Stormwater Management Authority, comprising senior council and government officials, has also been notified.

Brownhill Creek Residents group spokesman Tom Pearce condemned the years of “indecision and hand ringing”. He said: “It is disappointing none of the councils has seen this train wreck coming.”

But Michael Salkeld, the project’s director, said he “would expect” the scheme to be given a “clean bill of health”. The inquiry’s report will be tabled in Parliament.