A report by the Auditor-general on freshwater quality management by four regional councils - including Environment Southland - has been described by Federated Farmers as unhelpful and "seriously limited by its own limitations".
Lyn Provost concluded the Waikato Regional Council and Environment Southland were not adequately managing the causes of non-point source discharges (pollution from diffuse sources).
In both regions, significant intensification of land use meant more pressure on freshwater quality.
"The current regulatory and non-regulatory methods, and how they are being implemented in these regions, are not enough to reduce the known risks to freshwater quality.
"Both councils are trying to tackle the challenges of non-point source discharges and their cumulative effects, and there are some signs of improvement, but there is still significant work to be done," she said.
Ms Provost was encouraged to see strong collaboration, from high-level policy at government level to regional councils and dairy-sector representatives working together at a strategic and on-farm level.
Federated Farmers national president Bruce Wills said the report did not give enough recognition to the "enormous" amount of work being put in by farmers and others to improve water quality. He was concerned it did not look at government policies, point source issues or regional council monitoring of urban water quality or stormwater.
The report also made a range of recommendations to regional councils, suggesting they review their methods for reporting results of freshwater monitoring, include specific time-bound objectives in their long-term planning and also review their delegations and procedures for prosecuting to ensure the process was free of political bias.
Otago Regional Council environmental information and science director John Threlfall said the council already had a procedure in place excluding all political influence from the prosecution process.
However, it did accept more work needed to be done to reduce the risk of further land use intensification and was implementing this with its Water Quality Strategy and the proposed change to the Water Plan.
"We are following an effects-based approach, targeting the setting of water quality standards to maintain good water quality or improve where necessary."
Monitoring in Otago existed in most of Otago's key catchments, but in particular was focused on areas where "we believe there is more risk of deterioration".