Meridian's assessment methodology flawed, says scientist

The way Meridian Energy assessed the effects on the Waitaki River of a new power scheme was challenged in the Environment Court in Christchurch this week.

Fishery scientist Michel Dedual, supoenaed by the Lower Waitaki River Management Society to give evidence opposing the north bank tunnel concept power scheme, highlighted limitations of the "in-stream flow incremental methodology" (IFIM) used to assess the effects of taking 260cumecs of water out of the river between the Waitaki dam and Stonewall.

He suggested the IFIM methodology would be used on its own: "As a good way if you wanted to take as much water out as you can".

Dr Dedual outlined other methods which should have been used to address how much water could be removed from an aquatic ecosystem before significant negative effects occurred.

Under cross-examination by Meridian's counsel Jo Appleyard, Dr Dedual said he had not read evidence of Meridian's experts which pertained to his before he prepared his own evidence.

He was contacted about two weeks ago and it took about a day for him to prepare his evidence.

Since preparing his evidence, he had read some of that presented by Meridian's experts.

He was not familiar withnor visited the Waitaki River, nor was he familiar with Canterbury braided rivers.

His involvement as an angler and scientist was with central North island rivers.

However, he maintained Meridian should have used several methods, instead of just the IFIM model, to assess the impacts.