A Whangarei man says he will continue confronting Northland Regional Council over rivers fouled by farming.
Millan Ruka has bought camera gear and a jet boat to patrol waterways he remembers as pristine in his youth.
He says the rivers that feed into the Kaipara harbour are fouled by cattle excrement and dead cows; the banks are mostly unfenced and farmers are using the rivers to water stock.
Mr Ruka says he began documenting the pollution last year, and has sent detailed reports to the regional council, with little result.
However, he says he will go on confronting the council and hopes others will join him.
The regional council says it is hard to prove adverse effects on a river that is already dirty.