Neil Dignam shows the point where he says stormwater runoff has caused a 5m drop-off at Carlock Promenade, Karalee, near the bank of the Brisbane River.
Neil Dignam shows the point where he says stormwater runoff has caused a 5m drop-off at Carlock Promenade, Karalee, near the bank of the Brisbane River.

Land eaten away: Dodgy drain that has come back to bite

A DECADE-LONG dispute between Karalee man Neil Dignam and Ipswich City Council has reached a frustrating stalemate, with the authority deflecting responsibility for worsening erosion on the banks of the Brisbane River.

Mr Dignam says an inadequate drain installed by developers of the Riverside Estate back in 2004 is the cause of severe scouring on the lot next door to his property on Carlock Promenade.

The erosion has become so bad that there is now a 5m drop off in the vacant lot next door to Mr Dignam's yard, which he says is a both a safety hazard and an environmental catastrophe.

Himself a former Ipswich City Council employee, Mr Dignam has compiled a lengthy file on his correspondence between engineers, developers, and current and former Ipswich councillors, regarding the site.

 

Neil Dignam shows the point where he says stormwater runoff has caused a 5m drop-off at Carlock Promenade, Karalee, near the bank of the Brisbane River.
Neil Dignam shows the point where he says stormwater runoff has caused a 5m drop-off at Carlock Promenade, Karalee, near the bank of the Brisbane River.

 

At the heart of the dispute between Ipswich City Council and Mr Dignam is whether the erosion has been caused by the 2011 floods, or whether it is, as Mr Dignam claims, the result of a poorly constructed stormwater drain, which has allowed excessive overland flow to cause erosion over the past 16 years.

"The engineer that Ipswich City Council contracted back in 2011 to inspect flood and storm damage, Franz Jacobsen, was here in 2011 and noted there was significant damage," Mr Dignam said.

"His recommendation at that time was to extend the stormwater pipe further down the bank."

Mr Dignam has documents showing the works were on a list of repairs planned by contractor Aecom following the 2011 floods, but they never advanced past the design stage.

"By ignoring this recommendation, the council have turned what might have been a $150,000 job into one that might cost more than half a million dollars now," Mr Dignam said.

Mr Dignam says he was told in excess of 6000 cubic metres of sediment may have been washed into the Brisbane River as a result of the erosion.

 

Erosion has formed a dangerous gully on properties on the banks of the Brisbane River.
Erosion has formed a dangerous gully on properties on the banks of the Brisbane River.

 

His biggest fear, however, is for the safety of children in the area, due to the massive drop-off that has been created.

"You cannot really see the drop-off until you are standing over it," he said.

"Kids ride their bikes and play around here. If one of them fell in, I cannot see how they would be able to get out again, and if they were injured it would be extremely difficult to get help to them."

The Queensland Times submitted a range of questions about the site to Ipswich City Council last Thursday, however, we received a similar response to what was given to us the last time we covered the story back in July.

A council spokesman said a Queensland Ombudsman's report in 2017 agreed that Ipswich City Council was correct in its findings

"In essence, the delegate concluded that council's position, being the major scouring of the gully that has occurred is mainly due to riverine action in conjunction with the 2011 flood (and is not attributable to council's stormwater infrastructure in Lot 165), is not unreasonable," a senior investigator from the ombudsman's office wrote.

The ombudsman has declined to investigate the matter further since 2017.

"In closing its case file, the ombudsman's office said the complainant could seek his own independent opinion/advice," the council spokesman said.

"Ipswich City Council confirmed (last Friday) that it will conduct a further investigation of the storm water drain and surrounding land at the Karalee property, and will inform the property owner of the outcome."

Mr Dignam has sought expert advice on the situation, from the hydrological engineer Mr Jacobsen, who is familiar with the site.

 

The council storm water drain located roughly 130 metres from the banks of the river. Hydrological engineer Franz Jacobsen says it has concentrated stormwater flows over a small channel, causing massive erosion over a relatively short period of time.
The council storm water drain located roughly 130 metres from the banks of the river. Hydrological engineer Franz Jacobsen says it has concentrated stormwater flows over a small channel, causing massive erosion over a relatively short period of time.

 

In an emailed response to Mr Dignam, Mr Jacobsen says he was concerned at the state of the stormwater drain, which he says lacks "sound engineering practice" in its design.

He said Ipswich City Council should be alarmed "that Carlock Promenade does not meet the requirements of their own freely available standard drawings".

Mr Jacobsen said Ipswich City Council should have been aware of the shortcomings of the drain back in 2004 when it was built, and that "the token rock protection was overwhelmed and failed and the absence of adequate erosion protection led to the current constant erosion".

Speaking to the Queensland Times, Mr Jacobsen said that while damage was evident on the banks of the Brisbane River from 2011, the deep erosion directly down from the drain was clearly caused by flows from the drain, not river flows.

"Extending the drain further down the bank is the best way to fix it," he said.

"If nothing is done for another 10 years it will be worse still, but it is difficult to say how by exactly how much."

Ipswich City Council has not responded to follow-up questions from the Queensland Times.