A NEW hydrology report into the 2011 Grantham flood that killed 12 people has cleared the local quarry of any overwhelmingly negative impact.
The lengthy, in-depth report commissioned by the current flood inquiry stated the most likely impact from the quarry was to delay flooding by one to three minutes.
The Water Solutions report attributed that to the time it took to fill the quarry pit with water.
Instead, the 2m-high railway embankment that runs through the town was found to have worsened the flood.
The report stated the embankment blocked the path of floodwater that would otherwise have moved unrestricted on to the Sandy Creek floodplain.
Blocking the water's path increased peak flood flow intensities through west and central Grantham, according to the engineer who compiled the report.
It was also found to have created a concentration of flood flow to the northern side of the embankment at the Sandy Creek rail bridge crossing.
Lockyer Valley Regional Council mayor Steve Jones said council had been concerned about the rail line for many years.
"Governments of both colours have neglected our concerns," he said.
"This study shows they now need to strongly consider building the Gowrie to Grandchester corridor and remove the existing rail line completely."
The businessman who owned the quarry at the time of the flood, Denis Wagner, said he would not comment on the report until after the inquiry concluded.
He would not confirm or deny he was considering taking legal action against 2GB talkback presenter Alan Jones, who has repeatedly claimed the quarry worsened the flooding.
But Mr Wagner said there was a good basis for suing Mr Jones.
Some residents have told the inquiry they believed the quarry worsened the flood, but Mr Wagner has rejected the claims.
The report will be examined and the report's author will give evidence when the inquiry's public hearings begin again next week. - APN NEWSDESK
Update your news preferences and get the latest news delivered to your inbox.