The Coastal Otago River Communities Group wrote to Dr Wright in December requesting an investigation into minimum flows set for the Waianakarua River and Trotters Creek.
The group felt summer minimum flows went against expert and scientific advice provided to the council, were contrary to what the community wanted and put more emphasis on irrigation.
Although the group took part in the legal process the council followed to set the flow, it did not have the resources, including funds, to appeal the decision to the Environment Court.
Instead, it asked Dr Wright to investigate but she has now told the group that she also faced "challenges regarding resourcing" and had decided not to investigate.
However, she did recognise the need for a national environmental standard for minimum flows and increased environmental monitoring of streams.
Dr Wright suggested the group continue to pursue its concerns with the council and Minister for the Environment Nick Smith.
Group spokesman Morgan Trotter said yesterday the decision not to investigate was another example of a failing environmental process, again due to lack of resources.
"This is a very poor outcome for volunteer groups trying to protect our environment," he said.
When groups were no longer able to play the adversary under the Resource Management Act, there appeared to be no redress through the Parliamentary Commissioner for the Environment.
Mr Trotter said the regional council would now feel safe to go on putting the economic interests of abstractors ahead of the risks posed to New Zealand's natural heritage.
"Only when we have seriously overshot the environmental bottom lines will the consequences become evident and by then it may well be too late to correct the mistakes," he said.
Last year, after workshops, public submissions and a hearing, the council set a summer minimum flow of 200 litres a second for the Waianakarua River and 10 for Trotters Creek.
Initial recommendations were 20 litres a second for Trotters Creek and 270 for the Waianakarua River in summer.
