Creeks’ nitrogen levels high

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Oamaru resident, Peter Grant, is concerned that recent Otago Regional Council river quality studies have shown ‘extraordinarily high levels’ of nutrients in the Waiareka and Awamoko Creeks.

Mr Grant says he makes reference to the studies because of their significance and the ‘seemingly impossible task’ in front of the North Otago Irrigation Company in getting its shareholders to drastically change their farm management plans to meet council water quality rules by the 2020 deadline.

Mr Grant said both creeks’ NNN (nitrogen, nitrite and nitrate) levels are currently well above the required guidelines.

“Most businesses will gladly take on a challenge to reduce overheads and emissions or cut waste by figures of 30-70 percent. It’s a challenge but it’s do-able. When you start looking at the challenge of reducing leachate loss on pastoral grazing practices of 10-40 times current levels, you really need to review your whole business plan,” he said.

Rolling out the next stage of NOIC’s irrigation development, he said, means a doubling of cow numbers and the potential leachate problem.

Robyn Wells, chief executive NOIC, said the company acknowledge there has been an increase of nitrogen in the two creeks, but that other water quality parameters like dissolved oxygen have shown an improvement.

NOIC shareholders irrigate about 50 percent of the land in the Waiareka catchment and must have an environmental farm plan in place to take water.

“NOIC is working closely with the regional council, we have a Memorandum of Understanding in place, and we are currently updating our environmental farm plans to incorporate the new water quality requirements,” Ms Wells said.

“Water quality sampling undertaken by NOIC shows shareholders are able to operate within the new rule framework. The new thresholds provide a quantitative measure for farmers to assess their environmental performance and make improvements.”