The Environment Court has given a split decision on whether Otago's last wild river can be dammed for hydro-power.
The 2 to 1 verdict on a water conservation order for the high country Nevis River follows a full hearing in late 2012, which agreed that the Nevis valley was a nationally outstanding landscape.
Plans by Pioneer Generation for a small hydro-power dam on the Nevis date back to about 1990 and have been strongly fought by recreation and conservation groups.
Two Environment Court commissioners found the river's wild, scenic nature and native fish populations should be protected with a permanent ban on dams to protect kayaking and fishing.
However, Judge Jon Jackson issued a minority decision on Thursday, saying the way must be left open for a small dam.
The final decision must be made by the Environment Minister Amy Adams.
The Otago Fish and Game Council says it is expecting Ms Adams to give proper weighting to the court's majority decision.
Chief executive Niall Watson said says the Nevis Valley is accumulating so much protection, it is unlikely that a dam project would ever be viable.