Monitoring of algae and bacteria is set to begin at several popular lake and river swimming spots in Waipā over the summer months.
From December to the end of March, Waikato Regional Council will be checking for signs of E.coli, as well as cyanobacteria (the micro-organism that causes potentially toxic algal blooms), both of which can affect human health.
If significant bacteria are found during the regular monitoring, a health warning will be issued by the relevant District Health Board. Monitoring results and warnings will be published on the Land Air Water Aotearoa (LAWA) website, www.lawa.org.nz/explore-data/swimming.
Waipā District Council compliance manager, Karl Tutty, said as well as checking Waikato Regional Council’s website or LAWA for any warnings before heading to a swim spots, swimmers should also be carrying out visual checks of the water.
“Now that the temperatures are starting to rise, the conditions for bacterial growth are ideal so it’s really important for people to check the water before undertaking contact recreation. Any results we get from monitoring should be used as guidence only and do not necessarily mean the water is or isnt safe to swim in. Conditions can change between tests and cyanobacteria and toxins aren’t evenly spread through water bodies, so they may be concentrated in some areas.”
Waikato Regional Council environmental monitoring manager, Dr Ed Brown, said swimmers should be particularly wary of algal blooms which could cause health effects such as skin rashes, stomach upsets, and may even worsen hayfever or asthma.
“Algal hotspots include small lakes and side-arms of the hydro-lakes where water can be stagnant and the water temperatures higher than for flowing rivers. These factors can sometimes support the rapid growth of algae, resulting in very visible algal blooms, sometimes described as ‘pea soup’.
“You should also avoid swimming in rivers, streams and harbours for 48 hours after heavy rainfall events. That’s because the water is likely to be contaminated with animal faeces from rural and urban runoff, causing a tummy bug, a sore throat or skin infection.”
When carrying out a visual test prior to swimming, people should look for discolouration, any unusual smells or scum on the surface of lakes or on the riverbeds, he said. Not all swimming spots will be monitored by Waikato Regional Council.
Members of the public who see a possible bloom should phone Waikato Regional Council on 0800 800 401. Anyone who has been swimming and is concerned about their health should contact their GP or the Public Health Unit of the Waikato District Health Board on 0800 800 977.
Updates on health warnings can be found online: