Northland Regional Council is changing the way it delivers water quality results at popular summer beach and freshwater swim spots.
Council’s Coastal and Water Quality Field Operations Manager, Ricky Eyre says for many years the council has collected weekly water quality samples at swim sites over summer, with results delivered to the public through various means, including online through the council website and, in more recent years, the LAWA website.
“As well as being very labour intensive, due to the time limitations of sample analysis, management options are always retrospective and there is no consideration of changes in environmental conditions like rainy weather which can impact water quality,” said Mr Eyre.
In a bid to improve the situation, Council has been working to model recreational bathing water quality using the wealth of water quality data it has collected over the years.
The result is a system that establishes a relationship between historical results with environmental drivers (rainfall) to provide ‘real-time and near-future swimability predictions’.
Mr Eyre says the information on 50 coastal and 20 freshwater sites popular with swimmers and other recreational water users over the warmer months will be able to be presented year-round via the ‘Safeswim’ website www.safeswim.org.nz from December. The shift to Safeswim comes after six popular Northland sites were added to it in a low-key trial last summer.
Results will also be posted on the ‘Can I Swim Here?’ section on the national environmental reporting website LAWA – www.lawa.org.nz
“Among a host of potential benefits are improved knowledge of water quality at swimming sites, improving public understanding of potential health risks and providing real-time/forecasted water quality year-round,” said Mr Eyre.
“Safeswim also provides information on tides, physical hazards and lifeguard patrols, where appropriate, providing a ‘one-stop shop’ for users to make informed decisions on where to swim before heading off.”
He says despite the move to Safeswim, Council will continue to collect water samples throughout the year to ‘ground truth’ the model.
New monitoring sites will also be added to the Safeswim platform over the next year.
Mr Eyre says the system uses a series of pins/droplets to illustrate the advisability of swimming and other contact with water. While Council does not have the authority to close beaches or freshwater sites to swimmers, the information is provided for users to make informed decisions.
Water quality predicted to meet national guidelines is marked with a green water droplet -indicating a low risk of illness from swimming.
When water quality is predicted to exceed national guidelines, Safeswim will display a red water droplet – indicating a high risk of illness from swimming.
“Essentially it means that levels of bacteria indicate that more than 1 in 50 people are likely to become ill after putting their head underwater,” said Mr Eyre.
He said for most healthy people, water that meets national guidelines will pose a minimal level of risk.
“However, water below the guideline values may pose a potential health risk to high-risk user groups such as the very young, the elderly and those with impaired immune systems.”
Finally, a black pin on Safeswim indicates that the swimspot has been affected by a confirmed wastewater overflow and authorities ‘strongly advise’ against swimming as the risk is higher than normal.
