Test results on possible algal blooms and discolouration affecting parts of Lake Tarawera have returned at an amber level but an ongoing warning hasn't stopped people enjoying the water.
Earlier this week Lake Tarawera users were being urged to be vigilant, following reports of possible algal blooms and water discolouration.
The Bay of Plenty Regional Council said it had received a number of reports of possible blooms and discolouration affecting parts of the lake, including the Wairua Arm (near Hot Water Beach) and the area around the campsite at the outflow of the lake.
Algal blooms can be caused by potentially toxic cyanobacteria (also known as blue-green algae).
A spokeswoman for the council said today the advice issued for the public to be cautious about recreational use at the area still stood.
"The [test] results have returned as amber level which means that there will be regular sampling."
If the water looks discoloured, has an unusual odour or visible algae were present, it is best to avoid any contact with the water and swim somewhere else.
Water should also not be taken for drinking purposes from any part of the lake that looks like it may be affected by algal blooms or is discoloured.
Tarawera Ratepayers Association chairwoman Libby Fletcher said the people who lived around Lake Tarawera were good at being aware of and reporting any changes.
"We're very conscious of it, much more so than ever before.
"There will be locals who are cautious about swimming."
Committee member Terry Beckett said it was right for the council to issue a warning.
"The type of algae they are dealing with, it is potentially a problem. But temperatures have cooled down, we've had more rain and wind.
"I would be surprised if the algae continued to prosper."
He said obviously the people of Tarawera would be concerned.
"There was a major bloom in 2013, but we've been lucky with the weather really until now.
"We could sensationalise it, but I don't think it will amount to anything.'
Totally Tarawera owner Karen Walmsley said the warning hadn't seemed to affect people using the lake.
"As far as we're concerned, it hasn't stopped people.
"There have still been a lot of boats and swimmers and people out using the water."
For more information about cyanobacteria blooms and health see this Public Health Service advice.