The heritage values of the Nevis Valley were outstanding but could not be protected under a Water Conservation Order on the Nevis River, a special tribunal has found.
A report by the tribunal responsible for considering an amendment to the existing order on the river was made public last week.
It has recommended to Minister for the Environment Nick Smith that damming of the river be prohibited.
To change the conservation order, the tribunal had to find outstanding values or characteristics of the river that had not been recognised in the earlier Water Conservation Order.
Submitters gave evidence about the value of the native fish Gollum galaxiid, found only in the river, the trout fishery, heritage values, the rare flora and fauna, the wild and scenic characteristic of the river, and the importance of the site to Maori.
In its report, the tribunal said just one of those elements had "crossed the threshold" and was deemed to be outstanding - the Gollum galaxiid.
A ban on any damming of the river would protect the fish and its habitat.
The New Zealand Historic Places Trust said in its submission the Nevis was an "outdoor goldfield museum". Historic Places Trust Otago Southland manager Owen Graham was delighted the heritage values of the lower Nevis valley were recognised by the tribunal.
"It is a positive outcome for heritage, recognising the significance of the [Historic Places Trust's] research of the historic and archaeological values in the lower Nevis valley," he said.
The tribunal said the overall completeness of the remnant gold-mining systems met the definition of "outstanding".
However, to be considered as part of their deliberations, the heritage values would have to be "closely connected" to the river.
Although the river was linked to the heritage sites, most were not within the river or nearby.
Therefore, the protection of historical features fell outside the realm of the Water Conservation Order so other avenues would have to be pursued, the tribunal said.
The Historic Places Trust recently registered the lower Nevis area, to recognise its national significance as a historic gold-mining site.
