learn

Boxing Day Swim? Maybe not. Stormy Weather Prompts Water Quality Caution for Swimmers

Heavy rain and stormy weather sweeping across the country today mean it could be time to rethink your swim plans. LAWA (Land, Air, Water Aotearoa) is advising New Zealanders to avoid swimming in the great outdoors today due to the elevated risk of pollution in the water.

While swimming is a part of a Kiwi summer, after significant rainfall like we’ve seen over the past 24 hours, even swim spots that usually have good water quality can become unsuitable.

LAWA Recreational Water Quality Science Lead Dr Elaine Moriarty explained that heavy rain washes contaminants from the land into rivers, lakes, and coastal areas. This stormwater runoff can bring bacteria from animal faeces, wastewater overflows, and other pollutants into waterways, making them less healthy for swimming.

“Conditions can change quickly, especially after a lot of wet weather, which is why we recommend avoiding outdoor swims for two to three days after heavy rain.

“If you swim in water that’s been impacted by pollution, you risk getting ill with symptoms such as vomiting, diarrhoea, respiratory infections, or eye, ear, and throat issues.

“After a downpour, even waterways that generally have good water quality can be affected by stormwater runoff. The impact varies depending on the environment around the swim spot and activities and land use in the surrounding catchment.

“If you’ve noticed water running down the gutters or felt the need for an umbrella, there’s likely been enough rain to wash pollutants into the waterways,” said Dr Moriarty.

You can reduce your risk from getting sick by using the simple toes test: At your swimming spot, stand in calf-deep water. Can't see your toes? It's a no-go.

From a water quality perspective, LAWA recommends taking today to enjoy other summer activities with your whānau – the water will be there for swimming a couple of days after the heavy rain stops.

For water quality information for around 900 monitored swim spots across New Zealand, visit Can I swim here?