People are being warned not to swim in Waimarama's Puhokio Stream due to contamination.
Hawke's Bay's District Health Board Medical Officer of Health, Dr Nicholas Jones, said monitoring by Hawke's Bay Regional Council had identified high levels of E. coli in water samples taken on December 12 and 14.
The levels exceed the maximum values recommended in the Recreational Water Guidelines and indicate that, at the time of sampling, there were excessive amounts of faecal matter, either animal or human, in the water.
"The stream has previously been given a grade of very poor suitability for swimming and the recent very high levels of contamination are a reminder to avoid swimming or playing in this water," said Dr Jones.
"It is easy to see how parents might think the stream is a safer option for young children, but unfortunately there is a risk of children getting sick. However, the beach has very good quality water for swimming, remembering that young children need to be supervised for safety reasons," he said.
Hastings District Council has put up signs warning against swimming in the Puhokio Stream and is investigating the potential causes of contamination.
Dr Jones said other fresh water bathing areas can also become contaminated following rainfall events.
A quick test to decide whether to swim in fresh waterways, such as lagoons, streams or rivers, was to check whether you could see your feet when knee deep in the water.
However, for official guidance on where it's safe to swim, people were encouraged to check the Hawke's Bay Regional Council's website at www.hbrc.govt.nz for the latest water quality information, he said.