For more than three years, representatives of the Department of Conservation, Dunedin City Council and the Central Otago, Clutha, Queenstown Lakes and Waitaki district councils have been discussing the issue and they are now ready for formal decisions from their respective governing bodies.
Similar mergers have already taken place around the country, including in Southland, but if Otago authorities agree, Otago could get one of the largest rural fire authorities in the country.
Central Otago District Council chief executive Phil Melhopt, who is leading the discussions, said under the present system it could be confusing as to which fire authority was in charge of a particular area.
For example, the Department of Conservation was responsible for some rural Central Otago land - areas within and including 1km of Doc land - while the council was responsible for others and it could be confusing for people needing permits.
Under the proposed structure there will only be one agency for people to deal with, thereby reducing confusion.
While the new structure would cost more initially, it was expected to be cheaper in the long run. If it goes ahead, the enlarged authority would be able to take advantage of a $125,000 administration grant offered by the National Rural Fire Authority.
Together, the six authorities pay just over $1.5 million a year in operating costs and that was expected to rise by 2.2% for the merged authority, despite the grant.
Full-time equivalent jobs would rise by one to seven, but Mr Melhopt said there was no guarantee everybody would still have a job under the new structure.
It would not affect any of the volunteer fire brigades.
He said the amalgamation into an ''enlarged rural fire district'' was sparked by National Rural Fire Officer Murray Dudfield, who made a presentation to the Otago Mayoral Forum early last year to encourage a merger.
Mr Dudfield said 50% of New Zealand was now covered by amalgamated fire authorities and the model was being considered in other areas.
Although the authority representatives have all agreed to the merger in principle, elected members and Doc still have to agree.
The six Otago authorities will formally consider the merger this month, the first being the Waitaki District Council at its meeting next week.
If all agree, the new structure will come into effect on July 1 next year.
When asked what would happen if they did not all agree, Mr Dudfield said he was hopeful the benefits would be seen.
''I hope that the level of consultation that has gone on to date and with the benefits that will occur, we will get the support ... it is a voluntary process.''
The six authorities are being asked to make a three-year funding commitment to the new structure, based on existing ratios.
It will be up to the representatives of each to decide where the new authority's base would be.
Forestry companies and Federated Farmers were also involved in the discussions.