River cleaning bill '$10m to $30m'

If Manawatu people want the river cleaned they will need to fork out millions, Horizons Regional Council chairman Garrick Murfitt says.

Tests measuring oxygen changes in the river's water measured 107, about 30 times higher than it should be. While traditional water quality tests look at indicators like bugs or fish life present in the water, oxygen testing looks at how able the river is to cater for life forms.

The data came from research by the Cawthron Institute, commissioned by Horizons Regional Council for its One Plan hearings water chapter.

While Mr Murfitt says Horizons is not happy with the level of pollution, the money needed to improve it quickly is too much of a burden for the community.

The main sources of pollution come from treated sewage discharged by councils, and farm runoff.

"For local authorities to upgrade their sewage treatment plants would cost at least $10 million to $30 million," he said.

"It is going to take time. It's our responsibility to improve at a pace our community can afford."

Farm run-off from fertilisers and animal waste was another factor.

To cut back on farming would have a big economic impact on the region, Mr Murfitt said.

"We're not saying farmers do not have to improve their discharge but a big percentage have improved.

"We can't point the finger at any one sector. It is a community issue that we all have to be a part of but the community doesn't have a bottomless pit of money."

The council's One Plan has steps in place to tighten time lines in which local authorities have to make changes to their discharge levels, he said.

"The river is in a far better position to what it was 20 years ago."

Labour's water quality spokesman, Brendon Burns, said the Manawatu river was not the worst in New Zealand by any means.

Recent Ministry for the Environment figures put the Manawatu as the fifth worst in the country out of 35 rivers routinely surveyed for water quality.

The worst was the Waitara River, in Taranaki, followed by Whanganui, Waipa (Waikato/King Country) and Rangitikei.

Following Manawatu, in fifth position, came the Waihou (Waikato) and Canterbury's Waimakariri.

- © Fairfax NZ News