Aukaha chairman Edward Ellison has highlighted ongoing water issues concerning the Manuherekia River as a key factor for the relationship being formalised.
Representatives of Ngai Tahu were present at last month's council meeting in Roxburgh.
At the July 18 meeting, council chief executive Ian Hadland confirmed an agreement had been signed by Otago Fish & Game and Aukaha.
"It's something this council is pretty proud of. We can establish something high-level for working on water issues together."
The agenda at the last council meeting highlighted Ngai Tahu's interest in getting more involved with Otago Fish & Game.
Mr Ellison said the memorandum agreement was to co-ordinate responses to submissions and evidence in statutory planning processes affecting the Manuherekia River.
"With the advent of the Otago Regional Council's move for a plan change to address minimum flows in the Manuherekia River catchment and the significant burden that places on organisations such as Aukaha and F&G to participate effectively gave rise to the MoU."
Mr Ellison said the firm had been working alongside the council unofficially at the staff level on resource consent processes for several years.
"It is a symbol of a growing positive relationship that we hope carries further to regional planning matters relating to waterways and habitat."
Mr Hadland told the ODT that with many overlapping issues, the agreement made sense.
"We are both intensely interested in protecting the natural character of waterways, its life supporting capacity and opportunities for safe food gathering (mahinga kai)."
