The Otago Regional Council's approach to its proposed water quality standards has been called "too conservative" by freshwater scientist Marc Schallenberg.
He was one of 11 people to make submissions on the regional council's proposed water plan, water quality 6A changes in Dunedin yesterday.
Dr Schallenberg had real concerns how a "lay person" could measure and interpret data on water quality.
"You're asking too much of the lay community, who do not have the qualifications and expertise of scientists."
The approach was setting up the region for a "tragedy of the commons", with landowners reticent about taking responsibility and the resource depleted.
Lakes and rivers also needed to have the protection regionally significant wetlands had, he said.
Another worry was that the new standards were being based on current water quality levels, which had the potential to "entrench the status quo" in waterways already degraded, he said.
The council was ignoring the run-off from heavy rainfall and the 12-hour period following it was also a concern, as that was when the most pollutants entered waterways.
"It ignores the major contamination from land to fresh water. The ORC is turning a blind eye to the effect of land use. The approach is far too conservative."
University of Otago zoology department representative Dr Christoph Matthaei said staff wondered how the plan change would work in practice and there needed to be encouragement of a best management practice, such as fencing off riparian strips.
Otago Inshore Fishing Sector environmental consultant William Chisholm said the discharge of nitrates, phosphates, sediment and pathogens had the potential to significantly impact Otago's freshwater and inshore commercial fisheries.
The sector would like the plan to include policies and objectives relating to the effects of land use on water quality where freshwater interacted with the marine environment, especially around sedimentation, he said.
Southern Clams managing director Roger Belton said easing the performance requirement of freshwater polluters would have adverse effects on shellfish consumers and the industry. His clam beds were already closed 12 to 14 times a year due to possible contamination as rainfall flushed contaminants off the land into the water, Mr Belton said.
