A kaumātua is annoyed Ngongotahā children are being forced to swim in Waitetī Stream's muddy waters during a week of stifling temperatures because of nearby erosion work.
But the regional council said the work had to be done now and it had consulted with stakeholders, including iwi.
The stream's water is muddy and murky after the Bay of Plenty Regional Council carried out erosion protection work on the stream's banks this week.
Waitetī Marae co-chairman Guy Ngatai described the stream as an "absolute mess" and he was worried about the more than 30 children who used the stream daily to do "bombs" and swim.
The work began on Tuesday and Ngatai said the children quickly jumped out of the water when the usually clean stream turned muddy and murky.
However, he said they slowly got back in later in the day because the "scorching heat got unbearable" and they wanted to swim.
"Only 300m up from the mouth there is a digger dumping rocks in the stream. It looks like gravel and the river has gone all murky.
"It's a popular swimming hole and we didn't know anything about it."
Ngatai, who is also a trustee of Ngāti Rararanui hapū which is the kaitiaki of Waitetī Stream, said he should have been consulted so the children and their parents could have been informed, at least from a health and safety point of view.
He said in his opinion the regional council was giving preferential treatment to the homeowners who lived on the stream's banks when iwi had complained for many years about silt, logs and debris being in the river's mouth. He described that build-up as "literally choking the life force out of our awa".
Ngatai said if the work had to be carried out, the regional council could have waited at least until the children went back to school in a couple of weeks.
Regional council rivers and drainage area engineer Kerry Smith said the regional council was carrying out erosion protection work including removing an 80m steel sheet piles erosion protection structure.
Smith said it was put in around the 1950s and failed just before Christmas which was why it needed replacing now.
"They will also be adding rock armouring to protect the residential properties nearby and hope to complete everything by this Friday."
Smith said it had to be done now because the current summer months were the only months allowed for repair work in a stream or river as there were exclusion periods for native fish and trout spawning and migration throughout most of the remainder of the year.
"We apologise for any inconvenience this has caused for local swimmers."
Smith said the works were pre-notified to major stakeholders including iwi, the Department of Conservation and Fish and Game.
When asked why Ngatai wasn't informed, Smith said: "Just over 80 interested and affected parties are notified each week at present about work we are doing. Ngāti Ngararanui hapū were not specifically on the notification list but we will endeavour to work with them to ensure they are notified for any future works they deem relevant to them."
Smith said prioritising the removal of a collapsing steel erosion structure was a positive move to reduce risk to swimmers.
In response to criticism about giving homeowners preferential treatment, Smith said the regional council completed two large erosion projects at the Waitetī Marae in 2019, as well as vegetation management on request and stabilisation grassing and planting.
"Since the 2018 floods we have also completed rock armouring works adjacent to the marae and rock armouring at the river mouth. We have also removed fallen trees and debris."
Smith said Ngatai wrote to the regional council in August 2018 asking it to clear the sediment build up at the mouth and staff replied including aerial photographs of the mouth over decades.
"It is our belief that this is something that will come and go, controlled by lake levels, prevailing wind and storm events etc and of course supply of sediment from the stream."