Treading water

Even some of our national parks are failing the bare-minimum water-quality standards. 

- ANDREA GRAVES

cooling off in a river or lake on a hot day is one of summer's great pleasures. But is the water clear? Are the rocks slimy? Does it stink? Surveys repeatedly show that New Zealanders care about water quality - for swimming, drinking and food-gathering. For freshwater dwellers, it's life or death.

Freshwater scientists rely on more than their eyes, skin and noses to assess water quality - they take objective measurements. A nationwide survey using measurements of nitrogen, phosphorous, suspended sediment and E coli levels was published late last year by the Our Land and Water National Science Challenge. It showed that even some catchments that include national parks and conservation estates need cuts in contaminants to meet bare-minimum water-quality standards. Some farming groups expressed concern that the standards must be too strict.

Ton Snelder, the report's lead author, explains that the study shows only where improvements are needed at a catchment level.