ROUS Water, Far North Coast Weeds and Richmond River County Council are to merge.
The three county councils all voted unanimously for the merger to proceed, believing there are serious savings to be made through a simplified structure.
Rous chairwoman Sue Meehan said the merger has been discussed for five years and a state review of local government was flagging joint organisations.
"The two smaller county councils were proving to be unsustainable... It's great to be on the front foot rather than waiting for someone to tell you what is happening and to see clear savings and go for them," she said.
RRCC is the smallest council in NSW, with six councillors and six staff.
Rous Water is responsible for the region's water supply, Richmond River County Council (RRCC) is responsible for the health of the Wilsons and Richmond River, and Far North Coast County Council (aka Far North Coast Weeds) is responsible for weed eradication.
Cr Meehan said there would not be any job losses and all savings would be re-directed to on the ground work.
She said there had been no timeline set for the merger.
The footprints of the organisations are not the same, so agreements with Tweed and Kyogle councils were also needed for the merger to proceed.