Bill English says he would still swim in the Oreti River, and most of Dipton's residents seem to be backing him.
During Newshub's election debate on Monday night, both the prime minister and Labour leader Jacinda Ardern were questioned on the state of New Zealand's rivers.
Newshub political editor Patrick Gower asked English and Ardern what their favourite childhood rivers were, and whether they would still swim in them today.
While Ardern said she wouldn't swim in the Waikato River any more, English answered in the affirmative.
"Yes the Oreti River, I swam in it as a child and I'd swim in it now."
Although concern has been expressed over the quality of parts of the Oreti River, Dipton residents such as Ryan Harrington seemed to share the prime minister's confidence.