New Zealand's wildest and most scenic rivers need greater protection from developments such as hydroelectric dams, a report by the Parliamentary Commissioner for the Environment says.

Commissioner Jan Wright's report, released yesterday, said the scenic Mohikinui River, recently spared from a hydroelectricity project, was still vulnerable to harmful development because it flowed through loosely protected Crown land. Many other rivers were similarly unprotected.

Measures to protect precious free-flowing rivers had dried up because the process was long and costly.

Dr Wright told the Herald the issue involved weighing up two environmental benefits - the carbon-free energy from hydroelectricity schemes, and the ecological value of wild rivers.


"Where such conflicts exist between hydroelectricity and wild and scenic rivers - climate change versus natural heritage - I have concluded that we need to pay more attention to the protection of the rivers," the report said.

The benefits of hydroelectricity could be measured in dollars, through the Emissions Trading Scheme, but a specific price could not be placed on wild rivers.

"This is not to say it does not have a economic value - it is our environment that draws tourists to New Zealand and leads many of us to holiday in our own country."

Water conservation orders could be made to prevent the taking of freshwater or modification of a river.

But only four applications had been made in the past 21 years, since the orders were included in the Resource Management Act, and only two had succeeded.

There were 13 water conservation orders on rivers.

Dr Wright recommended that the Minister for the Environment investigate which rivers would be good candidates for protection. She said many wild rivers flowed through land over which the Department of Conservation had "stewardship".

This meant developers faced easier tests to get access to the land.


The Mohikinui River flowed through stewardship land, and another developer could apply to dam it immediately. She recommended the minister identify important rivers running through stewardship land and reclassify the land where necessary.