A petition calling for the Government not to exempt the Manapouri Power Scheme from the national standards set out in the National Policy Statement for Freshwater Management (NPS-FM) has been signed by more than 515 people.
The Waiau Rivercare Group launched the petition on Friday. The reasoning behind it listed on Parliament's website was that exception from the policy would remove the community's voice for the Waiau River for the next 50 years.
In the summary of the policy, it states the new NPS-FM would allow regional councils to "maintain freshwater quality below national bottom lines where it is necessary to secure the benefits of New Zealand's five largest hydropower schemes". One of the five was the Manapouri Power Scheme.
Waiau Rivercare Group co-chairman Paul Marshall said when construction of the Manapouri Power Station was completed, the Mararoa Weir was built in 1972 to allow additional water to be stored in the lake. This altered the volume of water flowing down the Waiau River.
Pre-control, river flow was 450cumecs to 500cumecs. Marshall said it now sat at 12cumecs to 16cumecs.
"The power scheme utilises a diversion of about 95 per cent of the pre-control flow ... science from 1993 suggested a minimum flow should be around 35cumecs to optimise the amount of fish habitat."
Through the consultation phase they advocated for a "sweet spot" of 35cumecs, which would increase river health.
The low river flow meant at times it was unsafe for swimming due to the presence of algal blooms such as cyanobacteria. The action for healthy waterways package new rules and regulations was set to stop the degradation of water quality and improve it within five years, as well as reverse past damage.
When the changes to the proposal were announced last month post-consultation, Environment Minister David Parker said, "New Zealanders want to go down to their local swimming spot in summer and be able to put their head under without getting crook".
Marshall said two years ago no swimmers could enjoy the popular spots due to cyanobacteria.
The petition closes on June 28.