Something fishy in stream

UNFIT FOR FISH: Simon Wise with the bucket-full of dead aquatic life he . shed out of Mangauika Stream on Monday night. 025071AD

Simon Wise (28) has been fishing in Mangauika Stream on his parents’ Te Tahi Road property on the slopes of Mount Pirongia for many years. He’s never had a catch like he got on Monday night - and hopes he never does again. After noticing that the stream looked murky and in places ‘frothy’, within 20 minutes Mr Wise had filled a 10 litre bucket with dead fish.

“There were dead eels, trout and cockabullies all through the stream.”

Mr Wise walked upstream past more dead and dying aquatic life until he reached what he believes was the source of the problem - the Waipa District Council water treatment plant.

“I certainly could not find any dead fish beyond the water treatment plant,” Mr Wise says.

He says the plant was being backwashed earlier in the day and he is convinced it overflowed the oxidation pond and into Mangauika Stream.

Mr Wise contacted Waipa District Council and Environment Waikato to express his concern about the contamination of the stream. Waipa staff arrived that night to carry out work on the treatment station pond. They shut down the backwash programme and the following day dug out the pond. They also collected water samples from the stream.

Environment Waikato contacted Mr Wise the following day, to get an account from him of what had happened and to advise that they were in contact with WDC.

Mr Wise was pleased that Waipa District Council moved reasonably quickly to remedy the problem - although he was disappointed some things had not been done such as clearing out the dead fish littered throughout the stream. He was concerned about‘downstream’ effects.

Council engineering manager, John Kerr says staff were sent out on Monday night after the notification came through that there was contamination of the stream. Mr Kerr says until the water samples are returned from the laboratory later this week, there is uncertainty over what caused the problem. He says a desludging of the water treatment pond has been carried out earlier than normal as a result of the problem, but says nothing ‘out of the ordinary’ has occurred. He is ‘baffled’ by the reaction from fish in the stream.

“It is possible it was run-off from the forest or paddocks, or some kind of natural occurrence.”

Mr Kerr wants to emphasise that the Te Awamutu water supply remains unaffected.

“We are doing everything we can to limit further damage while we work out what is going on,” he says. “Investigations are continuing and we are working with Environment Waikato.”

Environment Waikato visited Mr Wise yesterday , to collect water samples that he had taken on Monday night and a verbal statement from him.

“They had been up at the water treatment station taking photos of the pond, which they confirmed had not been cleaned out for some time and had overflowed,” Mr Wise says.