The lack of oxygen in the lake has led to thousands of deaths. Photo: Benjamin Wilson.
Waipā District Council has rejected a proposal from Te Awamutu company Ergozyme to clean up Lake Ngā Roto.
The lack of oxygen in the lake has caused mass wildlife deaths.
Ergozyme approached the council last month with a proposal involving their products to improve the lake’s water quality following a devasting algae bloom explosion which caused the death of hundreds of fish and other wildlife,
Company director Wium Mostert told The News his company’s products use a biotechnology to emulate how water is naturally cleaned over time.
After hearing Mostert’s proposal Waipā mayor Jim Mylchreest told the council “if it is as successful as claimed, then it could be the answer to our prayers”.
But the council have chosen not to pursue Ergozyme’s offer for the time being.
“At this time, we are not proceeding with the Ergozyme proposal, and we have informed the product supplier,” acting community services manager Brad Ward told The News.
The council have concerns about the level of risk associated with the product.
“While having been used in sewage treatment ponds, there is no evidence of the product being used in a complex natural lake environment such as Ngā Roto,” Ward said.
The proposal would also need to gain regional consent if it was ever to be actioned.
“Discharging a contaminant such as this to a water body would require a consent under Waikato Regional Plan,” Ward said.
Ergozyme’s proposal may still be considered as an option in the future. However, the company will first need to supply research and trial data that alleviates the concerns that council have with their product.
Mostert plans to come back to council with an array of different trial options.
“I’m not going to give up, we know it can work, it is just a matter of convincing them,” he said.
Mostert said the council has been sent trial results, but it wants to see the results first-hand.
“We will just have to work out another plan to show them it is actually not a problem.”
In the meantime, council have opted to continue undertaking measures that were identified in their recently completed 10-year Ngā Roto Restoration Plan.
The plan, finalised last September, lists weed and pest control as a top priority for the next two years, with revegetation work the next priority, beginning in 2024.
Fish and Game manager David Klee, wrote a letter to the council earlier this year to request that action be made at the lake. He told The News that because of rain and cooler weather, the lake is looking much nicer than it did earlier in the year.
But Klee warns that if no drastic action is taken this year to change the lakes hydrology, another hot dry summer could trigger repeat algae blooms.
“It’ll be fine from now right through winter, and then the cycle will repeat again,” he said.
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