With summer on its way, Otago Regional Council (ORC) staff will be sampling and testing water quality around the region in the next few weeks, with prospective swimmers advised to check the ‘Can I Swim Here?’ section of the LAWA (Land Air Water Aotearoa) website to see the latest weekly water quality results from December 1 until March 31.
General Manager Strategy, Policy and Science Gwyneth Elsum said water quality was prone to change, so it was important to confirm water was safe before swimming.
“Even the sites that typically have excellent water quality can see bacteria spike as a result of heavy rainfall washing contaminants from urban and rural land into waterways. That’s why we recommend people avoid swimming for 2-3 days after heavy rainfall and use the ‘Can I Swim Here?’ data to help decide if they want to swim at a particular site,” she said.
Council’s advice for swimmers in Lake Wānaka, Hāwea and Dunstan was as follows: “The water here is generally safe for recreational activities. However, bacterial contamination can occur from recreational users, or after rainfall, as stormwater and rural run-off may contain human or animal effluent.”
Potentially toxic algae (cyanobacteria) can also cause water quality concerns when there are toxic algal “blooms,” which were found in Lake Hayes in February of this year. Elsum’s rule of thumb was: if the lake is looking green, stay out of it and avoid any contact with algal scum.
This year, there will be new signage up at a number of popular sites directing swimmers to the information online at: www.lawa.org.nz/swim.