Two years ago, New Zealanders were shocked when contaminated drinking water sickened more than 5,000 people in the small town of Havelock North, with a population of 14,000. A government inquiry found that sheep faeces were the likely source of bacterial pathogens, which entered an aquifer when heavy rain flooded surrounding farmland.A second phase of the inquiry identified six principles of international drinking water security that had been bypassed. Had they been followed, the drinking water contamination would have been prevented or greatly reduced. Here, I ask if the approach recommended by the Havelock North inquiry to prevent drinking water contamination can be extended to reduce the impacts of nutrient contamination of freshwater ecosystems.