Rules are expected to be strengthened to further protect waterways from sediment and nutrient run-off.
"Until the new rules are in place, we strongly encourage good grazing practice over the winter months, both to protect waterways, and to prevent the need for enforcement," Saunders said.
Measures such as buffer zones between stock and waterways, and managing grazing carefully, helped reduce the likelihood of soil, nitrogen, phosphorus and E.coli running off paddocks into streams, rivers, lakes or wetlands.
The council would follow up on non-compliance identified from the air.
Responses could range from issuing advice to prosecution.