Some of the functions conducted by the State Emergency Service (SES), which employs more than 200 people at its headquarters in Wollongong, will be "merged" into the Rural Fire Service following the inquiry into the devastating NSW floods.

Premier Dominic Perrottet has promised no impact to the volunteers who work for the SES but said the "back office" functions will be merged in accordance with the inquiry's report by Mick Fuller and Professor Mary O'Kane.

But despite being asked for clarification on the impact to the SES, the Premier and Emergency Services Minister Steph Cooke are not giving details.

The Rural Fire Service (RFS) was better equipped to handle the huge volume of calls for assistance than the SES, which struggled during the floods in Lismore in February, Mr Fuller, a former NSW police commissioner, said at a press conference on Wednesday to release the inquiry's report.

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"If people ring Triple-0 for a fire, it gets put through to NSW Fire and Rescue. If people ring Triple-0 in relation to a flood, it gets put through to the SES," he said.

"Now the SES were clearly overwhelmed in relation to it, and we know - I heard evidence directly from unit leaders where they had turned off Beacon, which is their main system for calls and service, because they were overwhelmed.

"We heard evidence where up to 3000 calls for service were lost in Lismore alone in terms of people requiring flood rescue and as the Premier said, it's just not good enough for the community."

Mr Perrottet has committed to support the report's recommendations, including No. 12, that the "government implement, before the next storm season, a merger of the SES and NSW Rural Fire Services back office and corporate service functions, while maintaining their separate legislative identity, brand, uniform and volunteer membership."

How many jobs would be included in this shift, and whether an SES headquarters would remain in Wollongong, is unclear.

The Mercury has asked Mr Perrottet and Emergency Services Minister Steph Cooke for clarification, and whether an SES HQ would remain in Wollongong. A response has not been received.

Member for Wollongong Paul Scully said the move raised more questions than it answered for the SES in Wollongong.

"I am seeking more information and clarification about what the Premier's exact plans are and what the impact on Wollongong will be," he said.

"As the local MP, I want to see existing jobs at Wollongong SES HQ secured even if its role may change.

"It is my view that emergency services will always require a regional presence.

"Let's not forget we are heading into bushfire and storm season and nothing should divert attention from planning and response to keep the community safe across NSW."

Public Service union general secretary Stewart Little called on the Government to halt the merger, saying neither agency had sufficient resources.

"The RFS had hundreds of vacancies heading into the recent catastrophic bushfires and the situation has not improved significantly since," he said.

"The SES have had their budget repeatedly slashed by this government and desperately need a period of stability to consolidate.

"Neither the RFS or the SES have significant support staff resources as is. It's hard to see how merging their functions will improve matters."