The school had initially been closed for two weeks after students staged demonstrations over concerns about the school's administration.
However, the District Education Officer (DEO) reversed the decision after a series of meetings with teachers, support staff, the Board of Governors and security officials, saying learners' education could not be put on hold.
The DEO said the decision to reopen was influenced by appeals from parents and political leaders who warned that an extended closure would disrupt learning.
"The meeting with teachers and support staff guided us on the way forward, and we agreed that the school should reopen on Monday. Our main focus now is the learners," the DEO said.
He said the Board of Governors had formally handed over management of the school to the District Education Office, which will directly supervise the institution until the Ministry of Education and Sports appoints substantive administrators.
The DEO appointed district education inspector Hellen Athieno as interim headteacher, with Lillian Athieno serving as deputy headteacher.
He added that an education officer has been deployed to the school daily to oversee operations while the district closely monitors the institution.
"The headteacher has been stepped aside. Whether we are asked to manage the school for one day or one year, we are ready," he said.
According to the DEO, consultations with teachers revealed several operational challenges, including the absence of regular staff meetings, delayed commencement of lessons, teacher absenteeism and declining discipline.
To recover lost instructional time, he directed that lessons must begin at 7am instead of 8am with immediate effect.
He also warned that teachers who absent themselves without authorisation would face disciplinary action, including possible removal from the government payroll.
"There will be no more excuses. Since the District Education Office is directly supervising the school, action against absentee teachers will be immediate," he said.
The DEO said restoring discipline among learners would be a key priority and announced plans to engage parents and the Parent-Teacher Association in the school's recovery.
The District Education Office will also investigate allegations that learners have been paying for extra lessons and that the school has been charging fees beyond those permitted under the Universal Secondary Education (USE) programme.
"As far as we know, this is a USE school, and charging extra fees is not allowed. We shall investigate all the allegations and make appropriate recommendations," the DEO said.
He urged all learners to report back to school on Monday and appealed to parents to provide the necessary scholastic materials, uniforms and support for school feeding while encouraging discipline.
The DEO also thanked the local community and political leaders for supporting the school's reopening and encouraged residents to continue contributing to the institution's development, noting that parents had previously supported infrastructure projects and donated computers.
The District Education Office said investigations into the allegations that triggered the student unrest will continue alongside normal teaching and learning.