Update: Somerset County has closed Mountain Boulevard from the Watchung Circle to Anderson Road until 6 p.m., as crews continue to work on the water main break. Traffic in the area will be detoured to Stirling Road and Washington Rock Road.

Many Warren families woke Thursday to find the water supply drained, after a 7 a.m. break in the water line in Watchung limited supplies to the area.

The break is reported to be near Mountain Boulevard and Washington Rock Road, cutting water service to an estimated 50 homes east of the break but limiting flow to hundreds more, according to Richard Barnes, external affairs manager for New Jersey American Water.

Barnes said crews are working on repairs, which are expected to take six to eight hours to complete, barring any complications.

He added Warren and Watchung residents can get water at the Watchung Fire Company, on Mountain Boulevard, during the limited supply.

This follows a similar incident Feb. 12 in Warren, and one on April 8, 2011. Behind the series of breaks is a 50-year-old cast iron pipe, Barnes said. The pipes often break in the spring as the ground shifts from freezing and thawing cycles.