Police were called to the scene about 5.15pm yesterday after reports a person had gone missing after entering the Waikato River.
It is understood family and members of the public have been combing the area in a bid to find the teen.
Water Safety New Zealand's year-to-date preventable drowning toll, as of Tuesday, stands at four deaths.
That figure stood at five preventable drownings the same time last year.
Of this year's drownings, three were related to swimming events while the other person drowned rescuing others.
Three of the drownings happened at lakes around the country, while one happened at a beach.