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.