A staff member discovered the water main break around 5 in the morning.
School administrators came up with an action plan before students arrived.
Water was shut off to all buildings so crews could work.
Students went to shortened class blocks and got out at 11:40am.
"Actually, students will have 62 minutes per class period plus a lunch. That gave us enough time to have a school day and also when they shut the water down we won't have any access to water service," said Benton HS Co-Principal Dr. Jeanette Westfall.
The school is expected to be back to a normal schedule tomorrow.