Rivers turning into 'privatised drains'

A rise in river pollution revealed in a new study threatens the Kiwi way of life, the Green Party says.

"We're losing something fundamental to who we are. When rivers are too polluted for people to use, they are no longer wild, they're just privatised drains," Green Party co-leader Russel Norman said.

An Environment Ministry study made public yesterday found harmful nutrients such as nitrogen and phosphorus were on the rise, especially where waterways passed through farmland. Nitrogen levels rose 30 per cent from 1989 to 2007, according to data from 77 sites on 35 rivers.

Nutrients such as nitrogen speed algal growth in water, making it murky. Sunlight gets blocked, killing aquatic plants and making it hard for fish and other creatures to survive.

Toxic algal blooms boosted by high nitrogen levels were closing rivers, Dr Norman said. "It's a huge issue. People believe it's their birthright to swim in rivers and lakes."

Toxic algal blooms caused "high risk" health warnings for the Hutt River and the Wairarapa's Waipoua River last summer, with people told to keep out of the water. Blooms can kill dogs and give people skin irritation.

Environment Minister Nick Smith said there were increasing reports of polluted rivers in Canterbury, Wairarapa, Hawke's Bay, Rotorua and Southland.

"People are unable to swim, fish and enjoy them. It's a nationwide problem."

According to Greater Wellington regional council, 26 of 56 rivers and streams recorded poor or fair water quality last year, mainly in agricultural or urban areas.

Dr Smith said it was important not to get into "blame-the-farmers mode".

"Many of our urban streams have some of the worst water quality."

There was some good news in the ministry report, with a drop in "point source" pollution waste discharged directly into streams.

The Government has announced plans to revamp freshwater management, focusing on water quality, allocation and water storage.

Niwa aquatic scientist Bob Wilcock said there were signs efforts to clean up dairy farming were working.

For example, the 2003 Dairying and Clean Streams Accord aimed to exclude cows from 90 per cent of streams, rivers and lakes by 2012.

"Of course the offset of that is increasing conversion to dairying."

Dairy cow numbers almost doubled from 2.9 million in 1981 to 5.2 million in 2006.

- © Fairfax NZ News

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