Agency heads and the NSW government’s emergency services minister have defended the response to devastating floods in the north of the state.

Inadequate forecasts were the main driver of the response that preceded the disaster, a parliamentary committee was told on Wednesday.

Resilience NSW Commissioner Shane Fitzsimmons disputed suggestions that someone had “dropped the ball” in relation to the flood response.

“In hindsight, it would have been great to have all manner of things – if there was a forecast that indicated what ultimately happened, and there wasn’t a forecast,” Mr Fitzsimmons told the hearing.

Emergency Services, Resilience and Flood Recovery Minister Steph Cooke said she understood flood-hit communities were angry and frustrated.

“I will continue as the minister to fight tooth and nail for all the resources they (emergency services) need to do their job in the future,” Ms Cooke told the budget estimates hearing.

The State Emergency Service was involved in discussions with the Australian Defence Force from February 21 and had been receiving briefings from the Bureau of Meteorology.

A briefing on February 25 suggested flood levels had peaked in Lismore in the state’s northwest and that moderate flooding was predicted, Acting SES Commissioner Daniel Austin told the hearing.

“I had a conversation with the director-general of Emergency Management Australia. I provided him with the briefing I’d received that the situation was easing,” Mr Austin said.

“For the forecast height (of the river in Lismore), I believe we had the mobilised resources to deal with that and additional resources were being mobilised as the situation deteriorated.”

But he said the ADF was not “told to go away”.

The flooding that occurred days later, with the water peaking metres above predicted heights, had not been predicted.

Based on the forecasts made, it was not anticipated that the ADF would be required to provide specialist resources such as helicopters, Mr Fitzsimmons said.

But on February 27, the SES did activate a request that sent between 70 to 80 ADF personnel to Lismore to assist with doorknocking and sandbagging.

The next day, another request was made for helicopters and high clearance vehicles as Lismore residents who hadn’t already swum from their homes during the night clambered onto roofs to escape rising floodwaters.

When floods hit Lismore again in March, the river height gauges were malfunctioning.

Mr Austin said he had been made aware of reports of malfunctioning gauges but was yet to investigate, adding he had been advised by the BOM that all gauges were online.

“I need to make it clear, the SES does not own the gauges,” Mr Austin said.

The BOM, similarly, does not own all of the gauges, with some owned by councils.

Evacuation orders were again issued and then cancelled in Lismore before a second flood in late March.

Mr Austin said the risk of the levee overtopping did not materialise and the evacuation was cancelled, but unforecast, significant weather then hit and flash flooding occurred.

“It was not until after that occurred that the Wilsons River, later that morning, overtopped the levee,” Mr Austin said.

A siren on a Fire and Rescue NSW building was previously used to warn that the levee overtopping was not active because there was no power.

Mr Austin said the siren was not a formal warning procedure in Lismore.

Fire and Rescue NSW Acting Commissioner Megan Stiffler said the siren was primarily a memorial siren and using it as an informal warning system risked creating confusion among the community.

The hearing continues.

– AAP