Although students benefited from a broad curriculum that promoted and supported learning it was "not well placed to sustain its performance".
"The school faces significant challenges with relationships between key people in the school. These challenges need urgent attention to avoid impacting negatively on student outcomes," it warned.
A notice to place the school under limited statutory management appeared in the New Zealand Gazette in March.
In a newsletter to parents, school principal Liz Thomson said the move to appoint external governance would not affect the education of girls at the school.
"I would like to reassure you that this will have no bearing on the day to day running of
the school and on your daughters' learning. Ms Dalzell has been appointed to assist the Board and will take responsibility at a governance level for some of the Board's functions," she wrote.
The statutory manager was now working alongside a newly elected board of trustees.
Dalzell told the Herald the recent trustee elections had probably altered the situation with just three former members re-appointed to the board.
"I have got every confidence that the way forward will be very positive," said Dalzell.
The new board would be meeting with the Education Review Office next month to discuss what was necessary to address recommendations raised in the report and concerns held by the Ministry of Education.
A New Zealand School Trustees' Association representative was also at the school to help with specific training.
The latest development comes more than two years after the previous board commissioned an external review, which identified a number of issues adversely affecting students and the school.
The ERO report said significant issues relating to stewardship and management were yet to be fully addressed.
"They now need to fulfil their roles as professional leaders. They need to clearly communicate the strategic direction of the school with teachers so they have clarity about where the school is heading and what is expected of them in their professional roles," said the report.
The report recommended the Secretary for Education consider external intervention to bring about necessary improvements.
Ministry of Education acting head of sector enablement and support Steve Stuart said the limited statutory manager was appointed in March because of a range of concerning issues that were raised by the ERO in its November 2015 report.
"The LSM will work alongside the school's board of trustees to improve relationships between the board, the senior management team and teachers. The LSM has picked up responsibilities from the board of trustees for the following areas: employment, curriculum and health and safety."
He said he was pleased with the progress being made so far with the help of the LSM and the situation would be reviewed after a year.
