Southfield School for Girls in Kettering sent pupils home earlier today after a water main burst.
Parents of children at the school in Lewis Road were urged to contact them if they had a mobile to confirm their permission to leave.
An Anglian Water spokesperson said: “We had reports of low pressure and no water at 11am from a number of properties in the area.
“This is because of a burst three inch main on the nearby Pytchley Lodge industrial estate, but we were able to stem the flow and supplies were restored by 11.30am.
“We are sorry for any inconvenience that was caused.”