26 November, 2012
Study highlights pressures on Kakanui catchment water quality
A ten month Otago Regional Council (ORC) study of water quality in the Kakanui catchment has revealed that water quality
parameters have deteriorated in recent years, with many waterways exceeding nationally recognised guidelines for
nutrients (nitrogen and phosphorous) and E.Coli (bacteria).
ORC will continue to work closely with farmers throughout North Otago’s Kakanui catchment to ensure they implement
practices to halt the increase in nutrients accumulating in the catchment aquifer and waterways, ORC chairman Stephen
Woodhead said.
Cr Woodhead said the study’s findings were not surprising, given the large increases in stock numbers, and the types of
soils in the area. Some parts of the catchment had light soils with poor filtration qualities that would allow surplus
nutrients through, especially nitrogen, while some of the downlands had denser soils which can drive nitrogen and
phosphorous runoff into streams and rivers.
“This investigation provides new information for all of us. Everyone in the community needs to understand that this sort
of deterioration of the environment is not sustainable,” Cr Woodhead said.
The report, which is to be tabled at ORC’s natural resources committee meeting on 29 November, indicates that if these
trends were left unchecked, they would lead to nitrate accumulation in the Kakanui aquifer.
In addition, the high nutrient (NNN) concentrations provided by the lower Kakanui River and Waiareka Creek (dissolved
reactive phosphorus (DRP)) could stimulate the proliferation of algae in the Kakanui estuary.
The report noted that land use and farming practices were likely contributors to the problem. Dairy farming had
increased in recent years, and some farms did not have sufficient effluent storage.
Cr Woodhead said ORC planned to meet with local farming leaders to discuss its findings, and develop a strategy to
improve the environmental outcomes for the area’s waterways.
Chairman of North Otago Irrigation Company (NOIC) Leigh Hamilton said the company will work with ORC to carefully
analyse the report and understand how it relates to its activities.
“Our Audited Self-Management system is well embedded, and we have a framework in place to drive continuous improvement
in farm practices amongst our shareholders,” he said.
“We have a long history of collaboration with ORC, and we are keen to work with them to face any issues head on, and
contribute to the discussion around potential solutions,” Mr Hamilton said.
Cr Woodhead and Mr Hamilton said a lot of work was needed to satisfy community expectations around water quality, which
would take time.
However, they said that well-thought out improvements to farm practices could bring about observable improvements in
waterway health.
“We know there are improvements to be made on some farms to increase effluent storage, and top class effluent management
is crucial throughout the catchment”, Cr Woodhead said.
“We know there are farmers who need to fence off stock access to waterways and fine tune their irrigation practices and
nutrient budgets. We also know that the majority of farmers do not want to be shamed by prosecution and face hefty
fines.”
“I will be recommending to the natural resources committee that we plan a community meeting for the New Year. We’ll work
on strategic and practical approaches with NOIC and other farmers in the area, and present these along with the report
to the wider community,” Cr Woodhead said.
ENDS