The cultural impact of Whanganui Prison discharging its stormwater into Pauri and Wiritoa lakes is being assessed.
The prison is seeking to continue piping the water that runs off its roofs and paved areas into the stream that connects the two lakes and is paying for an independent cultural impact assessment.
It applied to renew the discharge consent before it lapsed in 2013, and the application has been publicly notified. There were submissions from the nearby Tupoho and Ngā Wairiki/Ngāti Apa iwi, and from private individuals.
One of them was George Matthews, who presented a map of nine significant sites around the perimeter of Pauri Lake at a January 31 meeting to inform the cultural impact assessment.
Those at the meeting now want to know more, and the sites could be protected.
Whanganui Prison director Reti Pearse has proposed filtering the prison's stormwater before it enters the lakes. An independent report on them found most of their unwanted nutrient and E. coli was from surrounding farms, not from the prison.
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Farmers have fenced off both lakes, and Horizons and volunteers have done a lot of planting around them and along a stream that feeds them.
The prison has upgraded its infrastructure and will test the result of the upgrade on its stormwater this year, Horizons Regional Council strategy and regulation manager Dr Nic Peet said.
The resource consent will go to a hearing this year as well.
Pauri Lake used to be popular for swimming and fishing, but is now subject to algal blooms. Matthews is concerned about the state of the fishery.
He has met with local farmers, who want to keep the lakes healthy.
"As New Zealanders we have all got to start looking after waterways. We are all culpable and we all have to do something together," he said.