WA public schools need more than $135.7 million to fix run-down facilities and crumbling classrooms, a State Government audit has found.
Inspectors identified more than 612 schools that needed urgent "priority one" works, costing more than $15 million.
Five schools need more than $1 million spent on each of them to bring them up to scratch. The audit of maintenance jobs outstanding is carried out by the Department of Finance's Building Management and Works every three years, with jobs prioritised into nine categories depending on urgency.
The Education Department said it gave top priority to works that posed a "potential risk to safety or health", such as staircases with concrete cancer or broken footpaths.
The total repair bill fell $10.3 million since the last audit.
But the figures show there has been little change at the State's neediest school, Derby District High School, which requires works costing $1.63 million, compared with $1.7 million identified in the 2010 review.
Six of the State's 10 most run-down schools are in the country.
John Curtin College of the Arts, whose principal was censured in Parliament by Premier Colin Barnett two years ago for warning parents the school was so dilapidated it was a threat to students' health and safety, also made the top 10, with works estimated at $845,920.
Education Department infrastructure executive director John Fischer said it spent about $93 million on maintenance in 2013-14. Some jobs identified in the audit had already been fixed.
Opposition Leader Mark McGowan said it was "inexplicable" that State debt had increased from $3 billion to $25 billion in the past five years, yet the Barnett Government had not dealt with the school maintenance backlog.
Education Minister Peter Collier said the Government's $80 million preventive maintenance program had been used mainly to replace roofs, air-conditioning and gas heaters and to treat concrete cancer. Forward estimates put aside another $37.3 million for school maintenance.