After years of campaigning for all farmers to fence wetlands or stream edges off from stock, cow effluent continues to flow downstream, says Millan Ruka of Environment River Patrol - Aotearoa.

Ruka regularly patrols waterways feeding in and out of the intricate Hikurangi swamp network and downstream into the Kaipara Harbour via the Wairua and Northern Wairoa rivers.

Many farmers have taken responsibility and fenced off waterways properly, but others have put in only rudimentary measures that do not stop cattle getting into the water and some have done nothing at all, Ruka said.

Two weeks ago a kayak paddle of the Kauritutahi Stream for 3km downstream from Poroti revealed cattle grazing unfenced banks, causing erosion and sediment and pollution to flow down to the Waipao Stream, and onward.


Beef and dairy cattle on three farms grazed the unfenced streambank, resulting in fouled banks and stock standing in the stream to graze on river weed and drink the water.

"In all three locations the situation is easily remedied with minimal cost," Ruka said.

Efforts by hapu, the Northland Regional Council, other groups and landowners to fence and replant both banks on a 7km stretch of the Waipao Stream are being undermined by upstream farmers not fencing their banks, Ruka said.

"We commend the farmers who have fenced off more than 90 per cent of the Kauritutahi over this 3km [but] our efforts are undone when farmers upstream do not fence off their properties."

The 1991 Resource Management Act states everyone has a duty to avoid, remedy, or mitigate adverse effects, and photographic evidence gathered during his patrol clearly shows "adverse effects".

Ruka has asked the council to write to and visit the farmers concerned.