Sixty-five percent of Canterbury dairy farms, which includes most of those on the Waitaki Plains, were fully compliant with their effluent discharge consent or permitted activity conditions, an improvement from 59% on the previous season.
Compliance officers visited each of the region's 900 dairy farms at least once during the 2010-11 dairy season, which ran until the end of May.
ECan commissioner Tom Lambie said it was very encouraging to see the ongoing improvement in the level of full consent compliance among dairy farmers.
"This improvement reflects the work done in collaboration with industry partners and other stakeholders," he said.
In 2008, ECan initiated a meeting with industry partners Fish and Game and Forest and Bird to discuss ways to improve levels of dairy-effluent compliance.
A combined industry and ECan group has been working collaboratively since then to improve the rate of compliance.
"There is increasing awareness among dairy farmers of the need to improve their environmental performance. The compliance figures show Canterbury's dairy farmers are making good progress in these areas," Mr Lambie said.
The rate of minor non-compliance among dairy farmers fell to 26%, from 33% last year. Examples of minor non-compliance included an incomplete management plan or minor ponding of dairy effluent.
The rate of significant non-compliance, however, was static at 9% compared with last season. Two years ago, it was at 19%.
Significant non-compliance issues included effluent ponding and discharge of effluent too close to waterways, as well as nitrogen overloading.
"We are continuing to work closely with farmers and industry partners to understand the reasons behind the occurrence of significant non-compliance and will continue to develop and implement tactics to reduce the rate of non-compliance."
The full report for the 2010-11 season will be released later in the year, once more detailed analysis, including regional statistics across Canterbury, have been completed.