Health Warnings Issued for Lake Okaro and Lake Rotoehu

Health Warnings Issued for Lake Okaro and Lake Rotoehu

28 November 2018

Health warnings have been issued for both Lake Okaro and Lake Rotoehu because of the presence of blooms of potentially toxic blue-green algae.

Contact with water affected by blooms of blue-green algae can cause asthma and hayfever attacks in some individuals.  Contact with the blue-green algae can also cause skin rashes, stomach upsets, and in some cases neurological effects such as tingling around the mouth, headaches, breathing difficulties and visual problems.

“The health warnings mean that people should avoid any activity which involves contact with the water in Lake Okaro or Lake Rotoehu,” says Dr Neil de Wet, Medical Officer of Health for Toi Te Ora Public Health.  It is advisable not to paddle, wade, swim, or participate in any recreational activity that might involve any direct contact with the lake water.

Algae may also accumulate and form scum collections along the shoreline of the lakes.  It is especially important that parents ensure that children avoid contact with both the water and any algal scum along the shoreline as this may be toxic.

It is also advisable to keep pets and livestock out of the water and off the shoreline.

Signage will be erected at both Lake Okaro and Lake Rotoehu advising potential lake users about the algal blooms. 

The Rotorua Te Arawa Lakes Programme partner Bay of Plenty Regional Council takes water samples from 13 key locations across the Rotorua lakes each year to check for blue-green algae while working to improve the water quality of the Te Arawa Lakes.  These monitoring sites include Lakes Ōkaro, Rotoehu, Rotorua, Rotoiti and Tarawera.  For more information head to

Up-to-date information on these health warnings and others for the Bay of Plenty and Lakes districts is available through these channels: