A LEADING QC has provided written legal opinion stating the Brisbane City Council was “plainly guilty of negligence” over its flood cover-up and and could have been sued for misleading and deceptive conduct.

Lord Mayor Tim Quinn has vigorously defended his decision to withhold since 1998 the alarming findings on Brisbane River flood levels from a range of experts.

The findings, in a series of reports in 1998 and 1999, were suppressed by the council pending further analysis, while ratepayers who relied on the free advisory service about flood-affected properties were given no inkling of experts’ grave concerns.

Cr Quinn, who said it would have been irresponsible to go public with alarming findings which were subject to further analysis, on Sunday provided the results of a new study showing that the probable levels in a one-in-100-year flood had reduced to normal.

However, Brisbane lawyer Tony Morris, QC, said the council’s strategy to withhold the earlier findings was ill-advised and had exposed ratepayers and the council to the potential for serious losses from litigation.

His opinion was backed by plaintiff law firm Shine Roche McGowan, which also provided written advice.

Another three-page opinion “of a general nature” from MinterEllison Lawyers said a local authority was entitled to form its own policy judgment about making information available to the public, but “a general claim of negligence, breach of contract and/or breach of statutory duty” could be made out under certain circumstances.

Carter Capner Lawyers said the council’s knowledge since 1999 “of at least the possibility” that its development control levels were wrong made it “liable to those persons who relied on the faulty data”.

Mr Morris said: “If the council had any concerns that the report might be flawed, they could have protected themselves by an appropriate disclaimer to the effect that the findings in the report are undergoing further analysis.

“I don’t understand how it can be argued that, when the council has a report regarding flood levels, it is prudent to withhold the report in case it is wrong. Surely the prudent thing to do is to publish the report in case it is right.

“There would have been nothing to prevent the council publishing the report with appropriate qualifications, so people could make their own judgments, instead of depriving people of the opportunity even to consider the risks.

It seems to be self-evident that not publishing involved a far greater risk than publishing with an appropriate disclaimer or qualification.

“If people are encouraged to build, and the report is later confirmed, people are stuck with homes in flood-prone areas. A claim for negligent advice would, in my opinion, clearly be available in the case of a person who suffers actual physical loss or harm, either to person or property, as a result of reliance on such advice.

“In the case of a person who purchased land, and/or built a house, in a flood-prone area, with the result that the house was inundated in a subsequent flood, a claim would be available in respect of physical damage to the house and contents and also injury or death of a person living in the house.”

Mr Morris said in terms of pure economic loss, there would also have been potential for claims by people whose land or homes had lost value.

The council charges $10.60 for flood maps for individual properties and, according to Mr Morris, could have “been exposed to a liability under the Trade Practices Act” for being a provider of trading activities involved in issuing false and misleading advice.