Horizons Regional Council begins its summer swim spot monitoring programme on Monday 6 November, giving everyone in the region the ability to check the quality of water at their favourite spots before taking a dip.
Every year, from November to May, Horizons staff collect samples from approximately 80 sites across the Horizons Region, which are then sent to an independent laboratory for testing. Results are then uploaded to www.lawa.org.nz so people can check before they head out.
Horizons environmental monitoring scientist Ian Hurst says staff monitor the levels of faecal indicator bacteria and potentially toxic algae (cyanobacteria) in the water.
“We test for E.coli at freshwater sites and Enterococci at coastal sites to measure faecal contamination,” she says.
“The presence of these bacteria in waterways suggests other pathogens, which are harmful to humans, may also be present. E.coli and Enterococci are not visible to the human eye, so we take samples and send them to an independent lab for processing.
“Potentially toxic algae include cyanobacteria, which appears as black mats on rocks in rivers and as green scum in and above water in lakes. This algae can be toxic to animals and people.
“Staff use a bathyscope (underwater viewer) to observe these algae in rivers. For lakes, a sample of the water is taken and examined with a microscope.
“Coming into contact with water where these organisms are present in sufficient quantities can lead to conditions such as gastroenteritis, respiratory illness, and ear and skin infections.
We update the LAWA website once we get the results, so people know which sites are suitable for swimming.”
Mr Hurst says people should always check LAWA for water quality results, but there are also other things they should be aware of, especially around and in rivers.
“Please stay out of water if it has been raining heavily within the last 72 hours, as this can create faster-flowing water and contribute to higher levels of faecal contamination.
“It is important to check any swim spot before swimming, but especially after heavy rain, as things may have changed beneath the surface since you were last there. It is especially important to check for large objects.
“Rivers and beaches across Aotearoa New Zealand can be unpredictable, and their power is easy to underestimate. Do not enter the water alone, actively supervise children, and stay out if you are not a confident swimmer.
“Also, avoid swimming close to cliff faces in case of slips, which can occur anytime. Finally, call 111 during any emergency at a waterway.
“Given the number of water-related tragedies we have had in our region during recent summers, it is important we all remember and follow safety advice. Anyone wanting further information about how to stay safe in and around rivers and beaches can visit www.watersafetynz.org.”
Mr Hurst says LAWA’s website holds information about the quality of water at swim spots across the country. Swim spots are tagged by a red, amber or green location marker, indicating the most recent test results and if the water is suitable for swimming based on Ministry of Health guidelines.
“No matter where you go this summer, you will be able to use the website to check results or find a swim spot.”