More than a quarter million Fairfax County residents either ran out of water or were getting only a dribble yesterday when the Fairfax County Water Authority was overwhelmed by a record-breaking demand.

Water authority spokesman James Warfield said the emergency should be over this morning as post-holiday demand returns to normal.

Warfield said the authority's treatment facilities were pumping yesterday at their capacity rate -- 118 million gallons daily -- but still not fast enough to reach all customers.

The areas affected were Herndon-Reston in the northern portion of the county adjoining Alexandria and parts of Springfield.

Three storage tanks south of Herndon, one near Fairfax Hospital and one at Gum Springs, fell nearly to the empty mark as demand peaked late in the day.

"The demand on any Labor Day is always high," said Warfield. "But this was just phenomenal. People just went bananas."

Officials theorized that the problem started when returning vacationers watered their parched lawns and families began getting their children ready for the start of school today.

Warfield said that tap water may have a rusty brown look when it starts flowing normally, but he said that condition would not pose a health hazard.The rusty look is caused by a sudden new surge of pressure that stirs up settled sediment at the bottom of the pipes.

The problem would not have occurred, Warfield said if the Authority's new Potomac River pumping and treatment facilities were in operation. But the facilities were in operation. But the facilities, still under construction, will not be ready for at least another year.

Three years ago the Water Authority, which serves more than 600,000 people in Fairfax and Prince William counties and Alexandria, was forced to impose water restrictions when its Occuquan Reservoir fell to a dangerously low level but the reservoir at this time is not below normal and was not linked to yesterday's problems.