Two classes had been sent home and were now isolating, he said.
"We consider all of those kids in the class to be close contacts. They have all gone home and they are isolating."
The school remains open and Watkins had made contact with parents this morning, he said.
"We are putting all the necessary procedures in today ourselves. We are just going to monitor it on a daily basis."
He said prior to finding out about the cases students had been learning in "year level bubbles" and separated during class and break times.
"We are trying not to have the kids mixing so there is no cross-contamination at morning tea and lunch. We are hoping to contain within those two classes."
Rotorua Girls' High School also had students isolating after a student at school last week tested positive for Covid-19.
More than 40 students and about three staff members were close contacts.
Principal Sarah Davis said the school pastoral care systems were "up and running" and they had made contact with affected whānau.
She said it was "fortunate" the infected student had only been at school for two days.
It was important the wider school community knew the school remained open and health measures remained in place.
"It is a learning curve - but it is one that we are prepared for."