Aerial surveillance by the council this winter revealed welcome changes to winter crop management.
Its environmental monitoring and operations director Scott MacLean said just five incidents would be followed up by staff compared to 19 last year.
MacLean was pleased with the level of compliance which was consistent with a general improvement in environmental compliance by the primary sector.
The winter inspections also looked at mechanical disturbance of waterways, forestry practices and stock pugging.
While the southern winter was milder than usual, McLean said farmers had taken steps to reduce the impact from grazing winter crops on water quality.
Low-lying areas such as gullies and swales could become highways for nitrogen run-off but best practice crop management such as creating buffer zones or grass strips in those areas, as well as strip-grazing across a slope instead of up and down, could help mitigate contaminants entering waterways.
Poorly managed crops could allow contaminants such as nitrogen, phosphorous, sediment and E. coli to enter waterways.
