Council monitors the concentrations of indicator bacteria every week from the beginning of November until the end of March.
To view the latest results:
Go to the Marlborough region swimming information on the LAWA* website
* Land, Air, Water Aotearoa. LAWA is a partnership between councils, Cawthron Institute, Ministry for the Environment and Massey University and has been supported by the Tindall Foundation.
LAWA provides two measures:
- Summer season monitoring - a recent snapshot based on a single result
- Overall recreational risk - a guide to give a general picture of water quality at a site. Updated annually, it is calculated from bacteria (E. coli or enterococci) data collected over the last three summers. The Overall Recreation Risk indicator is a precautionary approach to managing health risk and it not designed to represent health risk on a particular day. As such, a site can have an Overall Recreation Risk of ‘Caution’ but still be suitable for swimming some of the time.
The risk of catching an infectious disease from swimming in clear, clean water is usually low. However, after rainfall contamination occurs through runoff into waterways and there is an increased chance that you may catch a gut, ear, skin or respiratory infection.
The Marlborough District Council and Nelson/Marlborough District Health Board Public Health Service advise that after rainfall, it is best not to swim in discoloured water, especially for at least the first 24 hours and preferably 36 hours to minimise the risk of exposure to harmful bacteria. Further reduce your risk by:
- Avoiding areas where stormwater outlets discharge to watercourses.
- Avoiding areas with high runoff from intensive agriculture.
- A cost effective approach to measuring the concentration of microorganisms that could affect the health of swimmers is the use of indicator bacteria.
- The SFR Grade gives an overall measure of the recreational water quality of a site.
- The Council uses the ‘bathewatch’ software provided by Ministry for the Environment to assign SFR Grades.
- The MAC is calculated as the upper 95th percentile of indicator bacteria concentrations over five consecutive summer seasons.