(26 Nov 2018)

The Water Protection Society (WPS) is criticising the decision to declare the Oroua River the second most improved river in the country at this year’s New Zealand River Awards.

Each year the selection panel considers one of 4 indicators of river quality measured at just one place in the river. This year they considered the level of dissolved reactive phosphorus, DRP, downstream of the Feilding wastewater treatment plant.

DRP is one of the causes of excessive algae growth in waterways. It comes from runoff from farmland and wastewater treatment plants.

The problem with the award is that it is rewarding actions taken a decade ago rather than focussing on more recent performance. DRP levels at the site dropped by about 10 times after alum dosing began in 2008. This is a tried and trusted way of decreasing the amount of phosphorus in discharges.

The awards are based on 10-year trends and so still include data from 2008 when DRP levels were so high. In fact, the Oroua River was given an award in 2014 for the improvement in DRP level, so it has been recognised twice for things that happened once.

If, instead, the most recent 5 years of data is considered, there has been, at best, no improvement in the level of DRP in the river and according to the LAWA website it is very likely getting worse.

Furthermore, although over the 10-year period all measures of nitrogen pollution of the river were improving, over the most recent 5-years all of them were very likely getting worse .

So, on two of the most important controllable causes of poor water quality, DRP and Nitrogen, the Oroua River downstream of the wastewater treatment plant is probably getting worse. That is not a good basis for giving the Oroua River another award.

WPS chairperson, Dr Chris Teo-Sherrell, says ‘As a way of rewarding and promoting actions to clean up our streams, rivers, and lakes, we commend the awards. However, they shouldn’t be used as a smokescreen for inadequate action. All polluters need to make more effort to clean up their acts. That is yet to happen satisfactorily on the Oroua.’

About WPS: The Water Protection Society Incorporated (2014) seeks to have lakes, streams and rivers clean enough for humans to swim in without fear of illness and for the insects, fish and other organisms which should live in them to thrive there. We particularly promote the beneficial use of wastewater on land.

WPS is active in the Manawatu-Whanganui Regional Council region, particularly the Manawatu catchment. We have been submitters and appellants on various consents for wastewater discharges from municipalities and industry over recent years, including the Feilding, Foxton, AFFCO (Feilding), Pahiatua, Eketahuna and Whakapapa consents.

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