The Otago Regional Council (ORC) water plan has higher standards than the Government’s recently released freshwater quality target.
“The Otago Regional Council’s water plan includes much higher standards for water quality in our lakes than the bottom lines contained in the national policy statement for freshwater management,” ORC director engineering, hazards and science Gavin Palmer said.
“This is not something ORC has done arbitrarily – rather the strengthening of the water plan to include these high standards reflects community aspirations and values and feedback we have received from Otago people,” he said.
Central Otago and the Queenstown Lakes district have outstanding water quality compared with many other parts of the country, according to recent data released by the Ministry for the Environment.
Most water bodies in Central Otago and Queenstown Lakes are rated as having excellent or good water quality.
Three-quarters of the Clutha’s flow came from catchments feeding Lakes Hawea, Wanaka and Wakatipu, which were known for their “clean, pure water”, Dr Palmer said.
“The quantity and quality of Clutha region’s climatic conditions, catchment geology and a wide range of human activities involving the use, diversion and re-use of river water,” he said.
“Otago has good water quality on the whole. The effects-based nature of the water plan motivates and encourages landowners and managers to develop innovative management practices to minimise the impact on water quality of factors such as increasing population, increasing agricultural intensification [and] climate change.
“It also encourages them to monitor their own water quality on-farm by sampling and walking around their property.”
Dr Palmer said the ORC recognised the need for irrigation but also said “it isn’t disputed that the expansion and intensification of agriculture made possible by irrigation has the potential to cause increased deterioration of water quality”.
Increased nutrient levels in irrigation and drainage water, often from runoff from the land, caused eutrophication, resulting in the proliferation of algal blooms and aquatic weeds, Dr Palmer said.
“However, ORC has a robust resource consent application process prescribed by the Resource Management Act to ensure that irrigation projects strike a balance between boosting the economy and protecting the environment.”