AS THE rain pours down, inside the State Emergency Service Lismore City headquarters, members are being briefed ahead of their assignments.

SES Flood Intelligence Intelligence Officer Ed Bennett is assembling data regarding rainfall and probable river heights to ensure they can advise the community on what to expect during the severe weather event.

"At the moment the Wilson Rivers is about 6m and rising about 25cm an hour and it's expected to reach 7.2m about 6pm tonight and about 8.2m around 2am tomorrow (Wednesday)," he said.

"There no comparison between this and the 2017 flood ‒ back then the river was rising twice as fast."

Mr Benett said he expected the Lismore floodgates will be closed "as a precaution".

"At this stage it appears no residences or businesses in Lismore are under threat," he said.

"Unless we get a lot of heavy rain the levee will not be overtopped.

"But even when the rain starts to ease people must remain vigilant."

Meanwhile, Lismore SES Deputy Controller and Operations Manager Sue Brown was giving her teams a briefing on current and probable conditions ahead as part of their preparation to be ready to help their community.

Ms Brown said she hoped everyone will adhere to the SES advice, not to drive, ride, walk or play in floodwater.

"We have a flood rescue crews on standby here at the unit and a storm crew to go out and do sandbagging and roof jobs," she said.

"We are in contact with Richmond River High School and heard that they are sending their children home."