"Safety is the top priority of Round Rick High School and Round Rock ISD," Groff wrote in the letter. "Ensuring a safe and secure learning environment requires partnership between students, parents, campus and district staff, as well as law enforcement."
He added that Chaverria is not permitted to return to the campus.
Chaverria, who had been teaching for the past six years, shared a speech before she received her Teacher of the Year award.
"The most important role of a teacher is to help shape future generations to become successful members of our community," she said.
"More than any curriculum I teach my students, I hope that they will walk away from my classroom thinking of ways that they can make a difference in their community and impact the lives of others for the better."
Chaverria also led the school's Adopt-A-Child community service project, district officials said.
She has been released on bond after turning herself into authorities at the Williamson County Jail on charges of improper relationship between educator and student.