FLOOD MITIGATION: At a briefing to Lismore's councillors on the flood works, it was revealed the flood mitigation will divert water via be a wide, shallow plain, rather than a channel and cows will be back in the paddocks once it is complete.
FLOOD MITIGATION: At a briefing to Lismore's councillors on the flood works, it was revealed the flood mitigation will divert water via be a wide, shallow plain, rather than a channel and cows will be back in the paddocks once it is complete. Roslyn Hopkins

REVEALED: How Lismore's flood channel will really work

RATHER than an aqueduct, the Lismore flood diversion channel will be a smooth flood basin with a minor gradient.

When Lismore City councillors met at a briefing to discuss the forthcoming Lismore Flood Diversion Channel on Tuesday night, they were surprised to learn the project name was a little different to reality.

As Lismore faces its second anniversary of the devastating 2017 flood from ex-Cyclone Debbie, councillors Isaac Smith, Elly Bird, Bill Moorhouse, Nancy Casson, Darlene Cook and Vanessa Ekins, heard presentations from senior staff.

The council's executive director infrastructure services, Gary Murphy, said the briefing on the channel -which has been funded with an $8.2 million grant from the State Government - would give councillors background and content.

"This is not a project without risk," Mr Murphy said.

The council's project engineer, Aaron Hoffman, said the current consent allowed the council to extract half the amount of soil in the first year.

"Rather than a channel, the area will be 600 metres long with a maximum depth of up to 1.5 metres deep," he said.

"It will be like a big shallow, smooth drain."

After the works there will be cows back on the land and locals should not be able to tell the works have occurred, Mr Hoffman said.

He also explained that the flood mitigation works have a large sewer budget of around $1.5 million.

Mr Murphy said the mitigation project was "the length of three football fields."

The council's strategic planning coordinator, Paula Newman, gave councillors some background information on the project and spoke about consents for landfill.

Around 410,000 cubic metres of soil will be excavated to divert overflow from Leycester Creek around the airport.

The overflow will re-enter the river system below the city, providing residents and businesses with more time to plan their evacuation in major flood events.