No structures were damaged after the dam failed about 45 miles upstream from Supai, but some hiking trails and footbridges were washed out, she said. Trees were uprooted, the National Weather Service said.
As much as 8 inches of rain since Friday caused trouble even before the dam burst. A private boating party of 16 people was stranded on a ledge at the confluence of Havasu Creek and the Colorado River on Saturday night after flood waters carried their rafts away, Oltrogge said.
The boaters were found uninjured and were being rescued from the canyon, whose floor is unreachable in many places except by helicopter.
Rescuers were trying to find visitors staying at the Supai Campground and escort them to safety, Oltrogge said.
Evacuees were being flown to a parking area 8 miles from Supai and bused to a Red Cross shelter in Peach Springs, about 60 miles southwest of Supai, the spokeswoman said.
A flash flood warning was in effect for the area until the early evening. The area got 3 to 6 inches of ran Friday and Saturday and got about 2 more on Sunday, said Daryl Onton, a National Weather Service meteorologist in Flagstaff.
"That's all it took -- just a few days of very heavy thunderstorms," he said.
Supai is on Havasu and Cataract creeks about 30 miles northwest of Grand Canyon Village, a popular tourist area on the south rim. Havasu Creek feeds the Colorado, which runs the length of the canyon.
The flooding came on a weekend during the busy summer tourist season, when thousands of visitors a day flock to the canyon for spectacular views, hikes or to raft its whitewater.
The helicopters lifting residents out were from the National Park Service, the National Guard and the Arizona Department of Public Safety, Oltrogge said.
In 2001, flooding near Supai swept a 2-year-old boy and his parents to their deaths while they were hiking.
The Grand Canyon has been the traditional home of the Havasupai for centuries.