In past years Mr Watt has discovered piles of tails, household rubbish and sheep carcasses dumped along the riverside that he has reported to Masterton District Council, Greater Wellington Regional Council and Masterton police.
"I take my dog Pharoah down there every day. This sort of thing happens all the time and it's where our children swim and fish," Mr Watt said.
He "gets in the ear of council" when he discovers rubbish along the nearby stretches of riverbank.
"It's just a crying shame."
Mr Watt said he would prefer to simply walk his dog along the river tracks without the burden of staying alert for rubbish.
But he feels obliged to complete his near daily patrols, he said.
"It would be a whole lot easier if people didn't dump their rubbish down there, but someone has to watch out until they do."