The society was one of four appellants against four resource consents granted by Environment Canterbury late last year for the north bank tunnel concept scheme between the Waitaki dam and Stonewall on the north bank of the river.
An earlier appellant, the Waitaki Protection Trust, has reached an agreement with Meridian and will not be opposing the scheme when the Environment Court starts hearing appeals in Oamaru from June 22.
However, the river management society's appeal remained in place, its chairman, Bill Penno, said.
Mr Penno said the society was having discussions with Meridian to isolate the issues which would be covered by the appeal.
Discussions were in the early stages and he was unable to say whether any agreement could be reached with Meridian.
The society met this week and was "actively proceeding" with finalising evidence for its appeal.
Mr Penno said funding assistance had been received from the Ministry for the Environment's legal assistance fund, which would be used to meet the costs of expert witnesses.
The fund provides non-profit groups with financial assistance to advocate for an environmental issue of public interest at resource management cases.
Issues which the society would be focusing on would be water quality, the health of the river and community wellbeing.
"The society believes there is enough water in the Waitaki to satisfy the health of the river, needs of irrigators, river users and power production," Mr Penno said.
Several people were involved in helping the society prepare submissions for the court hearing, including its legal counsel, Camilla Owen, he said.
Other appellants are Ngai Tahu, Ngai Tahu-Mamoe Fisher People and Black Point farmer Garth Dovey.
Meridian is having discussions with all parties, including Ngai Tahu, in an attempt to avoid court action if it can.
Ngai Tahu did not want to comment yesterday on its discussions.
