"I think that things do well if they get a refresh and a new person, new energy and maybe a new vision," she said.
"Every five years in education there's a massive refresh. If I'm going to remain am I going to be the best driver of that?"
She said the school would remain precious to her and she was proud of the children.
"I'm really proud of how our children interact with one another," she said.
"It will be with great sadness I leave. I've been with families going through trauma and celebrated with families."
She said the school had a lot of staff members who could be leaders and it was time to move over and let some of them through.
Stewart also leaves behind her role as president of the Rotorua Principals' Association, which she took up in 2017. A new president will be voted in when she leaves.
The school board of trustees is asking members of the Rotokawa School community what values and characteristics they want in a principal, as well as what is important within the school, as part of the process of hiring a replacement.
Stewart said it was important to consult with iwi, children and teachers so the board could feel confident in whoever was hired.
"All of our community have ownership of where their children are coming. By consulting with iwi and teachers and students we find out their aspirations.
"I think our school is really desirable."
Stewart will see out the rest of the year as principal.
