Swimmers advised to take care before diving in after rainfall

Horizons Regional Council’s swim spot monitoring results have shown many river and beach sites are currently not suitable for swimming or collecting kai following the recent heavy rainfall across the region.
 

Indicators that determine the grading for swim spots, which is E.coli for freshwater sites and Enterococci at coastal sites, can increase significantly with high rainfall as contaminants from urban and rural settings are washed into waterways.
 
Horizons science manager Elizabeth Daly says it is important that the public continue to review the Land Air Water Aotearoa (LAWA) website www.lawa.org.nz for the most up to date results and suitability for swimming at all sites.
 
“An example of this is Waitārere Beach in Horowhenua and Kai Iwi Beach in Whanganui, which have shown high levels of Enterococci this week and resulted in a no swimming status for the sites,” she says.
 
“Waitārere and Kai iwi beaches are two of approximately 80 swim spots Horizons monitors across the region on a weekly basis for water quality and two of 10 beach sites. Last season beach sites were considered safe for swimming between 73% and 92% of the time, with Waitārere Beach being suitable for swimming 80% of the time and Kai Iwi 73% of the time.
 
“The region has experienced a decent amount of rain over the past week, so although it might be a beautiful day at your swim spot, it is important to remember that a location at the bottom of the catchment can be affected by rainfall upstream. It’s really important to always check the water is clear before getting in.
 
“This may take some time depending on forecasted weather and river conditions.
 
“Enterococci is a naturally occurring bacteria found in the gut of humans and animals and at high levels indicates a health risk to people when swimming or participating in other water related activities.
 
“If the coastal swim spots council monitors for contact recreation returns a result greater than 280 Enterococci per 100mL the swim spot is resampled within 24 hours following Ministry of Health guidelines.”
 
In addition to Enterococci at coastal sites, our science team monitors for potentially toxic algae (Cyanobacteria) and E.coli at freshwater sites such as rivers and lakes.
 
“Water quality samples from swim spots are sent to an independent accredited lab for testing.
 
“Results are received within 48 hours and are updated on the LAWA website, www.lawa.org.nz. Interactive maps show each of the swim spots tagged by a red, amber or green location maker to indicate that week’s bacteria results and whether it is safe to swim based on the Ministry of Health’s guidelines.
 
“LAWA holds swim spot information for the whole of New Zealand, so even if you are heading away you can still use the website to check results or find swim spots. It is important to note however, that even if LAWA is showing a swim spot is suitable for swimming you should still check the water when you get there.
 
“Take a look and see if the water is clear, meaning that you can see into the water. Check there is no debris such as rocks and branches, be cautious of how fast flowing and unpredictable water can be, and always actively supervise children.
 
“If the water smells odd or is a strange colour it should be avoided. In general, do not go swimming within three days of heavy or prolonged rainfall and if you do get sick after swimming in any lakes, rivers or beaches contact your doctor for advice.”