Justice Secretary Angela Constance said an investigation was being held into what happened at Forth Valley Royal Hospital.
The sum is the highest among Scotland’s 14 health boards, with nearly £4 million spent on agency nurses over the same period.
Forestry and Land Scotland staff are currently trying to find out the extent of the damage caused by Friday’s weather.
Staff from Scottish Power Energy Networks have been working round the clock to restore electricity following Storm Eowyn.