Editorial: Fail mark for river quality a real disgrace

5:30 AM Thursday Oct 18, 2012

It is appalling that so many of our rivers are not clean enough for swimming. The Ministry of the Environment has found the water quality at more than half the recreational spots it monitors to be poor or very poor. A further 28 per cent were fair, which carried a risk of illness for anyone swimming there.

It's not clear how many of those locations are used predominantly for swimming rather than other forms of recreation such as boating, rafting or fishing but it hardly matters. As the Green Party water spokeswoman Eugenie Sage lamented yesterday, it is disgraceful that people can no longer confidently go to their local river for a swim.

The reason is obvious. This is a farming country, and while most farmers may be doing their utmost to keep fertiliser and stock effluent out of streams and rivers, they cannot be doing enough.

Fortunately, most New Zealanders live within reach of the sea and beaches that offer better and safer swimming in every sense than a river. The ministry has found beaches and lakes to be much cleaner. But as long as some prefer a river, and Greens frequently cite rivers and streams as an indictment of Tourism NZ's "100 per cent pure" image, it is important to get them cleaner.

A level of safety fit for swimming is a high standard. Swimming demands a drinkable standard since it is the ingesting of micro-organisms that poses the hazard. A ministry official says the sites it monitors are chosen for their susceptibility to risk factors that might make swimmers sick and are not representative of the overall water quality in the country's swimming spots, but even so, the results are disturbing.

The monitors have gone to popular swimming spots such as Matata at the mouth of the Tarawera River, known to be polluted by the Kawerau mill, and to Waikato River bridges at Horotiu, Huntly, Mercer and Tuakau. Children playing in the river need more effort to be made to reduce farm run-off and lower the faecal count. It is important to stop and punish unauthorised discharges.

More surprisingly, Northland's rivers have rated poor or very poor at every place the water was sampled. Nobody should be jumping into the Kerikeri River near the Stone Store or perhaps any other river in the north.

Auckland's most polluted water courses are in Manukau. The Puhinui Creek features twice on the Auckland Council's worst sites for freshwater ecology and Otaki Creek near Middlemore Hospital is bottom of the list. If cows are the main source of rural contamination, in cities it is cars. Oil and brake fluid released onto roads is carried by rains into stormwater drains and end up in streams. Too often in heavy rain wastewater systems overflow and add to the contamination.

While water quality of a number of Waikato rivers has improved over the past decade, nearly the same number have deteriorated. They still have levels of nitrogen, phosphorus and E. coli several times above acceptable limits.

The last Waikato Regional Council report into the water quality of 17 rivers in the Hauraki region showed that the Piako, Waitoa and Waihou rivers were in poor to intermediate condition, being oxygen-depleted and murky. A survey, conducted between 2000 and 2009, showed they had concentrations of nitrogen and phosphorus five to seven times above guidelines.

Farmers express surprise at these results, saying effluent is no longer washed from milking sheds straight into waterways. Maybe, but they will have to go to greater expense to stop farm pollutants leaching into the rivers where so many people, particularly children, take a swim.