Hidden groundwater powers our rivers: Our Freshwater 2026 warns why early action matters

Our Freshwater 2026 shows how central groundwater is to daily life, supplying drinking water to nearly half of New Zealanders and around 80 percent of everyday flow in many rivers.

What happens on land leaves a lasting imprint. Nutrients, sediment and contaminants from farming, urban life, existing urban landscapes, and other land uses can wash into waterways – and can also seep into groundwater.

This is visible in national monitoring. Between 2019 and 2024, E. coli was detected at least once in 45 percent of 998 monitored groundwater sites highlighting how easily contaminants can move from the land into groundwater stores.

The report shows why storms can be problematic for freshwater. Extreme rainfall events can pick up and carry pollution and sediment, moving a lot of it very quickly.