Pioneer Generation wants to allay fears it will "flood the Nevis Valley" if it gains consent for hydro-electric development on the Nevis River.
The question of whether the door will be left open to potential hydro development on the river is the subject of a legal battle before the Environment Court.
Under the water conservation order (WCO), hydro development is not ruled out. However, changes to the order have been proposed by the New Zealand and Otago Fish and Game Councils to prohibit any damming or diversion of the river.
A tribunal appointed by the Ministry for the Environment heard the views of more than 240 submitters in 2009 and 2010.
It recommended the order be changed to ban damming, to protect the habitat of a rare native fish, the Gollum galaxiid, found only in the upper Nevis.
The tribunal's findings have been appealed to the Environment Court, which will hold an inquiry and make a recommendation on the matter to the Minister for the Environment.
Pioneer Generation chief executive Fraser Jonker said yesterday the company had taken heed of the concerns expressed by submitters and was giving an undertaking that its plans for hydro development "will effectively leave the valley alone".
"We understand this river is not ours. It's everyone's and we're prepared to work in, so everyone is happy," Mr Jonker said.
The geographic upper limit of any development proposal would be the Nevis Crossing.
"In other words, we will not consider any proposal that will impact on the Nevis Valley above the Nevis Crossing bridge."
Any future reservoir would be smaller than the size of Butchers Dam, near Alexandra, and would not be visible from the Nevis road.
