Media release

Potentially toxic algae confirmed at Falls Dam

Wednesday 19 February 2020

Testing has confirmed today that algae samples taken from Falls Dam on Monday afternoon are the potentially toxic cyanobacteria, blue-green algae (Anabaena lemmermannii). Warning signs are in place at this site.

It is advised that humans and dogs keep out of water contaminated by potentially toxic algae, and avoid drinking or touching it.

A general rule of thumb is that if the water is looking green, to stay out of it and avoid any contact with algal scum. If you have swum in water that is contaminated with toxic algae, rinse off with fresh water as soon as possible.

ORC encourages dog owners to familiarise themselves with toxic algae and know what to look for when exercising dogs in or around rivers and lakes.

Anyone who suspects they are experiencing a reaction due to contact with toxic algae should seek medical attention.

If you spot green algae in lakes, or dark mats in streams and rivers, contact ORC on our 24/7 pollution hotline, 0800 800 033.

For more information on potentially toxic algae, see LAWA’s factsheet: