Lake Tarawera users are being urged to be vigilant, following reports of possible algal blooms and water discolouration.
In a media statement, the Bay of Plenty Regional Council said it had received a number of reports of possible algal blooms and water discolouration affecting parts of Lake Tarawera, including the Wairua Arm (near Hotwater Beach) and the area around the campsite at the outflow of Lake Tarawera.
Algal blooms can be caused by potentially toxic cyanobacteria (also known as blue-green algae).
The statement said water sampling was under way to determine if cyanobacteria were causing these blooms and water discolouration.
Medical Officer of Health, Dr Neil de Wet, said lake users should be vigilant and exercise caution before any contact with lake water.
If the water looks discolored, has an unusual odour or visible algae are 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.
Further advice will be provided when results of sampling become available, the statement said.
For more information about cyanobacteria blooms and health see https://www.ttophs.govt.nz/vdb/document/43.