PORTLAND — Water service to a neighborhood on outer Congress Street was fully restored Monday night to residents and business owners who had suffered for most of the day without any water to drink, take showers with or flush toilets.

Michelle Clements, a spokeswoman for the Portland Water District, said a water main break was repaired around 5 p.m. Water was turned back on at 6:45 p.m.

The cause of the water main break, which was reported around 6 a.m., may never be known, she said.

The break disrupted traffic and the lives of people who live in the neighborhood of Congress and St. John streets. A section of Valley Street was also affected by the water outage.

Outbound traffic on Congress Street had to be diverted for most of the day as workers tried to fix the water main break near St. John and Congress streets. The break left 20 buildings without water service and closed at least two businesses.

The break occurred in front of the Hong Kong Market at 945 Congress St. Electricity to the Inn at St. John and Hong Kong Market was shut off because water flooded the basements of the two buildings, Clements said.

Guests at the 39-room inn either checked out by 11 a.m. or left for the day as workers pumped more than 4 feet of water from the basement, said manager Terry Morrison.

“We’re hoping to allow guests to return later today,” Morrison said around noon. “That won’t happen until everybody signs off and tells us everything’s OK — gas, electricity, plumbing — everything. Right now we’re taking it minute by minute.”

The sidewalk in front of the Hong Kong Market collapsed and the area was cordoned off, forcing the business to close for the day. It’s usually open daily from 9 a.m. to 7 p.m.

Monday’s disruption follows other recent breaks that have been attributed to the advanced age of water mains in the city.

The cast-iron pipe that broke Monday was installed in 1908, Clements said. Some mains in the city date to the late 1800s.

The district serves more than 190,000 people in 11 Greater Portland communities with water drawn from Sebago Lake.

Among them, Portland and South Portland have the oldest and most heavily used water lines, Clements said.

The district adopted a system improvement program in 1985 to help maintain more than 1,000 miles of water lines.

It currently budgets $3 million a year to replace pipes based on age, frequency of breaks and complaints from customers, Clements said.

– Staff Writer Dennis Hoey contributed to this report.

Kelley Bouchard can be contacted at 791-6328 or at:

kbouchard@mainetoday.com