Whangaehu River most improved

Horizons Regional Council chairman Bruce Gordon proudly accepted a New Zealand River Award on Thursday night for the Whangaehu River.


The Most Improved River Award celebrates waterways showing long term trend improvements in water quality. A panel of scientists judge approximately 600 sites using long term data stored on the Land Air Water Aotearoa (LAWA) website lawa.org.nz.
This year’s award acknowledges improvement in E coli levels, with the Whangaehu River showing a 10.8 per cent improvement trend.
“Not only was the Whangaehu River the most improved in our Region, it is also the fourth most improved nationally,” says Cr Gordon.
“A lot of time and resources have gone into work programmes in the catchment that contribute to improving water quality.  This includes riparian fencing and planting, as well as erosion control planting, by both farmers and Horizons.
“Around 125km of riparian fencing has been put in place over the past ten years and around 1 million trees have been planted. Almost 400ha of riparian land has been retired.”
In addition to this array of land-based remedial work, Horizons has worked with Ruapehu District Council to upgrade the Waiouru and Ohakune wastewater treatment plants to significantly reduce the bacteria load of their discharges.
“The Waiouru plant alone has reduced E. coli from a median of 141,360 MPN/100ml between 2010 and 2014, to a median of 0-4 MPN/100m in the past few years. Horizons has also increased monitoring of dairy farm effluent discharge to land consents for the catchment. 
“The success of the Whangaehu River’s improved E.coli trend is definitely one to be shared with landowners, ratepayers and the District Council.”
Cr Gordon says it’s pleasing to note that work will continue in the catchment due to central government funding.
“A recent application to the Freshwater Improvement Fund has seen the Ngā Wai Ora o te Whangaehu Freshwater Improvement Project receive $590,000. This will be part of the $1.68 million that is planned to be spent in the catchment on initiatives delivered by Horizons, Ngati Rangi and landowners.”
The Whangaehu River award is the fifth river award for the Manawatu-Whanganui Region. Previous awards have gone to the Oroua and Makuri rivers and Mangapapa Stream.
Water quality trends across the Region for January 2007 to December 2016 show an improvement in E.coli trends at 17 per cent of 56 sites and 0 per cent decreasing. Total oxidised nitrogen is improving at 35 per cent of sites with 2 per cent declining. Dissolved reactive phosphorus is improving at 22 per cent of sites and 7 per cent are declining.
“While these numbers are worth celebrating we know there is still much work to be done. We believe that with a combination of both regulatory and non-regulatory methods, and by everyone working together, we will continue to see improving trends across the Region.”     

The Whangaehu River has an enormous catchment covering nearly 2,000 square kilometres, with a total stream length encompassing 3,326 kilometres of tributaries such as the Mangawhero and Makotuku. The headwaters of the Whangaehu are the crater lake of Mount Ruapehu on the Central Plateau, with the river winding itself through the Ruapehu and Whanganui districts before entering the Tasman Sea 8 kilometres southeast of Whanganui.

E coli is a type of bacteria commonly found in the intestines of warm-blooded mammals, including people and birds. It is often associated with intensive dairying and while not generally life threatening, can lead to more serious diseases such as giardia or hepatitis A.

The New Zealand River Awards are run by Cawthron Foundation, with support provided by the Gawith-Deans family trust, Living Water, Tourism Holdings, Ministry for Environment and the Department of Conservation.