Like our beaches, NZ's rivers and lakes have their own set of dangers, but they aren't patrolled and many of their most dangerous hazards are hidden beneath the surface. As such, drownings in NZ rivers are more common than in any other water environment.

Generally, New Zealand's coastal and fresh waters are very safe to swim in 2026, but travelers must check water quality alerts before diving in. The primary risk is not wildlife (shark attacks are extremely rare), but rather bacteria and toxic algae. After heavy rainfall, urban and agricultural runoff can cause high levels of E. coli or enterococci, making beaches temporarily unsafe for 48 to 72 hours. In many lakes and rivers during the summer, Cyanobacteria (toxic blue-green algae) can bloom, which is harmful to humans and potentially fatal to dogs. In 2026, the best way to stay safe is to use the LAWA (Land, Air, Water Aotearoa) website, which provides real-time "Can I Swim Here?" data for over 800 spots. Additionally, the Pacific and Tasman coasts have powerful rip currents, so always swim between the red and yellow flags at patrolled beaches to avoid being swept out to sea.