enlarge The Associated Press/The Canadian Press

Pauline Branston delivers newspapers in Fredericton, New Brunswick, on Wednesday as the St. John River continues rising.

enlarge Gregory Rec/Staff Photographer

The dropping water level reveals a little more of some submerged cars in the parking lot of a Fort Kent apartment building.

enlarge Gregory Rec/Staff Photographer

Gregory Rec/Staff Photographer... Town workers constructed an earthen dam along the Fish River, seen here at the junction of West Main Street and Blockhouse Road in Fort Kent on Thursday, is credited with keeping parts of Fort Kent out of the floodwaters.

enlarge Gregory Rec/Staff Photographer

The St. John River is still flowing into the International Bridge between Fort Kent and Clair, New Brunswick, Canada, in this photo taken at 7 a.m. today. The river crested overnight and is now receding.

enlarge Gregory Rec/Staff Photographer

John Bouchard watches water in the basement of his father's house on Stockhouse Road in Fort Kent Thursday as Gary Voisine keeps an eye on the pump.

enlarge Gregory Rec/Staff Photographer

Dan Freeman balances on a trailer hitch Thursday in the flooded yard of a Fort Kent home. He was helping another resident retrieve belongings from the house on Blockhouse Road.

Click here to see a map of the flood area.

Click here to monitor the St. John River's flood level.

Click here for today's updates on the St. John River flooding.

Historical crests of the St. John River in Fort Kent:

• 27.31 ft on April 30, 1979
• 26.95 ft on May 1, 1974
• 26.60 ft on April 17, 1994
• 26.33 ft on April 19, 1983
• 25.76 ft on April 30, 1973
• 25.59 ft on April 11, 1991
• 25.56 ft on April 27, 1983
• 25.30 ft on May 16, 1961
• 25.11 ft on May 11, 1969
• 25.10 ft on May 5, 1933

Source: National Weather Service

For on-going updates on flooding in Fort Kent today, please click here.

For a video taken in Fort Kent today, please click here.

FORT KENT — Authorities evacuated dozens of homes and businesses Wednesday as rising floodwater spilled into downtowns and threatened dams and bridges in northern Maine.

Scientists called the event a 100-year flood for the St. John River. It was caused by driving rain and the melting of the heaviest snow accumulations in memory.

More than 3 inches of rain sent the St. John to more than 5 feet above flood stage Wednesday night. Much of downtown Fort Kent was underwater by early afternoon.

Authorities expected water to spill over a dike along the river, which runs between Maine and New Brunswick, before it crested at 2 a.m. today.

"We're evacuating all the main streets, going to all the businesses and telling them to close up for safety," said Fort Kent Police Chief Kenneth Michaud.

Floods also forced evacuations downriver in Van Buren and in the Penobscot County town of Mattawamkeag, where the Penobscot and Mattawamkeag rivers spilled over their banks.

A half-dozen Washburn residents were ordered out of their homes after a culvert in an earthen dam between Salmon Brook and Mill Pond washed away, threatening a concrete dam downstream.

"I've never seen it like this," said Ryan Goodine, a firefighter who was one of the six residents who were forced to leave their homes on Wednesday.

Goodine has lived in the small town west of Caribou for 30 years.

Wardens said the Mill Pond dam had cracked by midafternoon, and the National Weather Service issued flash flood warnings for the town.

The Mill Pond dam holds back about 12 feet of water, spread out over about 20 acres, firefighters said.

"If this lets go, we would have an issue or two," said Mike Matowitz of the Washburn Fire Department.

Local officials started watching the St. John River in Fort Kent last week, when rising waters caused concern on the Canadian side.

Those waters had been receding until the deluge of rain this week, said Joseph Hewitt of the National Weather Service.

There was still a half-foot of snow on the ground after a winter that dumped around 200 inches of snow in the region, and that melting snow exacerbated the situation.

"In response to that, a lot of these rivers took off," Hewitt said.

He said it was the worst flooding ever seen in Fort Kent, a town of 4,200 residents.

Meteorologists expected the river to crest overnight at just under 31 feet -- nearly 6 feet above flood stage and almost 4 feet higher than the 1979 record.

Authorities focused their attention on the International Bridge, between Fort Kent and New Brunswick, which would stand only slightly above water level if the forecast held true.

The river measured between 27 and 30 feet through much of Wednesday, gradually rising as the day wore on. It topped 30 feet around 8 p.m.

"Another couple of feet really won't make a difference -- they're already suffering up there," said LeeAnn Allegretto of the weather service. "The main concern is the bridge."

The Maine Emergency Management Agency activated its 24-hour operations center in Augusta and Gov. John Baldacci, who requested federal disaster assistance for Aroostook County, toured the affected region by helicopter.

Dozens sought refuge at an emergency shelter at the University of Maine at Fort Kent, which opened as police evacuated homes in the morning.

The displaced included Patricia Sherman, who for the past several days has watched the St. John River rise from her second-floor apartment on West...