Minot, North Dakota (CNN) -- With record water levels poised to inundate the North Dakota town of Minot, the mayor and the state's governor congratulated citizens on an organized and efficient evacuation
"It's been a very orderly process," Mayor Curt Zimbelman said Wednesday of the evacuation process. Gov. Jack Dalrymple said it had "gone extremely well."
Earlier Wednesday, sirens sounded in Minot, urging residents to abandon their homes in the face of major flooding. Water is already overtopping the city's dikes, which are leaking in some places.
There are roughly 12,000 people in the evacuation zone in and around Minot.
Zimbelman and Dalrymple warned that more water than expected is headed toward the town, and it will likely arrive sooner than expected. The Souris River is expected to crest on Monday, two to three days earlier than had been forecast. Zimbelman said the river is expected to rise to a level five feet higher than any previously recorded.
Residents were given until Wednesday evening to evacuate because of what state emergency services spokeswoman Cecily Fong called "historic proportions of water." There are also concerns the Souris River may be rising more rapidly than expected, Fong said.
The National Weather Service predicted record flooding as heavy rains and dam releases cause the river to swell at Minot.
Minot got some support from a hometown hero who was halfway around the world.
Actor Josh Duhamel, in Moscow for the "Transformers: Dark of the Moon" premiere, asked for donations to the local Red Cross. "My heart goes out to all the incredible people of Minot & surrounding areas," Duhamel said on his Twitter account.
The Souris River, which locals call "The Mouse" after the French translation of its name, flows through the center of town, and there are several homes and businesses along its low-lying banks.
Fearing the main levees would not hold back the water, emergency workers have been constructing local levees around a school and the Broadway Street Bridge, a main thoroughfare.
Residents appear to be heeding evacuation warnings. In a sign they're taking the flooding seriously, some residents were pulling up carpets because they are easier to remove now than after their homes have been inundated with water.
Not everyone, however, was planning to evacuate.
Troy Erickson, 44, lives across the street from the perimeter of the evacuation zone and said he plans to ride out the flood.
His neighbor has a bucket loader and they have distributed several loads of sand and gravel around four houses, which are home to 13 people, he said. They have "lowered a couple hundred sandbags" on top of the mixture, he said.
"We've got more sandbags coming to have just in case we need to build it higher," said Erickson, a lifelong North Dakotan. "It if happens, it happens."
He said he is "a little bit" frightened because he's never been in this situation, though he was a toddler during the flood of 1969.
Minot, in the north central part of the state, is the fourth-largest city in North Dakota. The evacuation order covers a third of its population, Fong said. Residents have until 6 p.m. Wednesday to leave.
The river at Minot, which currently stands at close to 1,555 feet above sea level, is forecast to rise to 1,559 feet on Friday or Saturday -- which would be a record. The river hit 1,558 feet above sea level in 1881.
The Souris River looks like a "U." It swoops in and out of North Dakota from Canada.
CNN's Richard Benson contributed to this report.