An independent inquiry has found environmental conditions on a central Queensland port expansion were virtually meaningless.

In fact, it appears almost no effort was made after the announcement of the fix-up job to ensure it met its goal.

The scientific inquiry into the expansion of the Gladstone Port and associated dredging activities has found that the environmental restrictions were too vague to actually be enforced.

The Federal Government commissioned the report into a leaking bund wall. The wall was designed to keep sediment on dry land and out of the harbour, but was found to have leaked into the water from June 2011 to July 2012.

The inquiry found “aspects of the design and construction of the bund wall were not consistent with industry best practice”.

It also said that the material used to hold back the sediment was inadequate, and the geotextile layers eroded under pressure.

The investigation found water quality monitoring sites around Gladstone were placed in the wrong areas, and that the federal Environment Department failed to retain compliance records.

But the plan may have been doomed from the start, with the investigators finding environmental conditions set up by the Commonwealth lacked any specific detail, which would have been necessary for their effective enforcement.

Reports say the investigation has not shed any more light on the outbreak of fish disease in the Gladstone harbour at the same time as the bund wall was leaking.

The best official response still comes from a Department of Agriculture, Fisheries and Forestry report in 2013, which found that flooding and fish spilling from a nearby dam were the main causes of the disease.