A spokesperson for the Victorian Government's Department of Education said GSSC was classified as a "state critical infrastructure project".
“As such construction will continue during this period,” the spokesperson said.
Under circuit-breaker lockdown restrictions, slated to last until at least 11.59 pm on Wednesday, February 17, only "critical" construction sites are permitted to continue works.
Those listed as "critical" include public infrastructure, work for national security and defence purposes and projects previously approved as "state critical" or "essential".
The department could not confirm how many of the daily site workers were from outside Greater Shepparton, but said all contractors were adhering to the same COVID-19 restrictions.
More than 800 workers have been employed on site throughout construction, 90 per cent of whom are locals.
“All contractors working on the Greater Shepparton Secondary College site are considered permitted workers, in line with current requirements,” the spokesperson said.
“All school building projects have rigorous COVID-Safe plans in place to manage and monitor risk.”