The beef, dairy support cattle and deer will be excluded from lowland rivers in 2025. The draft plan defines "dairy support cattle" as dry cows and dairy replacements.
Mr Ruka, who carries out Environmental River Patrol Aotearoa (ERPA) kayak monitoring of Northland rivers, said "dairy support" was a new category of cattle classification helping dairy farmers avoid the challenges of the Fonterra clean streams accord.
"'Dairy support' was not a term I had heard used until about three months ago," he said.
"This rubber-stamping of Friesians as beef animals expands the dairy industry and is a licence for farmers to have dairy stock on river banks."
Mr Ruka said beef or dairy support cattle could make as big a mess of a stream as a dairy herd.
He has been monitoring the Ngunguru River, where last week he photographed a dead cow hooked on willows above a popular swimming hole 250m up the river from the bridge on Coal Hill Lane.
"Several locals are concerned that cattle are unfenced further up the river on the opposite bank up from Coal Hill Lane," he said.
Mr Ruka produced a Ngunguru River report which led to him being invited to attend a Ngunguru River catchment group which the NRC set up last November to discuss sediment and erosion issues emerging around the time pipi beds were declining in the Ngunguru estuary. The group is expected to next meet in the Ngunguru Hall on October 27.
NRC land management adviser Wayne Teal said although the group thought sediment could contribute to shellfish mortality, they were still waiting for the results of Ministry for Primary Industries tests which could find bacteria to blame for the pipi dieback.
Many people considered forestry harvesting was largely responsible for an increase in Ngunguru River sedimentation, but forest companies were meeting their consent requirements while some pastoral land was not subject to the same rigorous monitoring, Mr Teal said.
Mr Ruka considered pine pollen could play a part in the reduction in pipi numbers.
And he said that with beef and dairy support cattle not excluded from rivers until 2025 ERPA work towards cleaning up waterways still had some way to go.
NRC monitoring and consents manager Colin Dall said although the draft regional plan could become operative in 2018, farmers were to be given several years to comply with river exclusion rules because of the significant investment in fencing and water reticulation which could be involved.
The council had recently served abatement and infringement notices on three Northland farmers whose cattle had been in waterways.
Mr Dall said the council was getting tougher on repeat offenders, particularly farmers who had declined offers of fencing subsidies.
The NRC environment fund is this year providing around $1.25 million for fencing and other land management subsidies.
