Many Colorado communities remained cut off by flooding Monday as heavy rain continued to fall, making search-and-rescue missions up canyon roads treacherous for local and state authorities. Surging waters, which so far have damaged thousands of homes and claimed seven lives, led President Barack Obama to sign a declaration of disaster over the weekend.
Four people in Boulder County and one in El Paso County are dead, and two women missing in Larimer County are presumed dead, officials said. As many as 1,254 people are unaccounted for. That number includes people who are missing and those who are cut off from aid because of floodwaters.
State emergency officials said flooding had destroyed an estimated 1,500 homes and damaged 17,500 others and that 11,700 people have been evacuated.
PHOTO GALLERY: Images From Boulder County
The search for stranded people, from the Rocky Mountain foothills to the plains of northeastern Colorado, grew more difficult Sunday, with airlifts grounded because of heavy rainfall.
"Finding the people who are unaccounted for is one of the highest priorities, and five teams of Boulder County Sheriff's Office detectives are dedicated full time to this task," said Boulder Sheriff Joe Pelle in an afternoon update posted online by the Boulder Office of Emergency Management.
About 560 Colorado and Wyoming National Guard members have been called in to assist the Federal Emergency Management Agency with disaster relief in Colorado, officials said.
Some 1,750 people have been rescued from communities and homes swamped by overflowing rivers and streams, but numerous pockets remain cut off from help, officials said.
The additional rain, falling on ground that has been saturated since Wednesday, created the risk of more flash flooding and mudslides, according to the National Weather Service.
Rain began pelting the state earlier this week, with Boulder especially hard hit, seeing 7.2 inches of precipitation in about 15 hours starting Wednesday night.
Areas that were already flooded faced further thunderstorms, lightning and torrential rain on Sunday night.
Obama signed a disaster declaration and ordered federal aid for Colorado on Saturday, making federal funding available to affected individuals in Boulder County. Other counties could be added later.
Obama also called Colorado Gov. John Hickenlooper for an update on the flooding and emphasized his commitment of federal aid for the flooding.
In Morgan County, Sheriff James Crone told KMGH-TV a bridge collapsed and the raging South Platte River divided the area.
The river was expected to flood until at least Tuesday, and Crone worried the continuring rain could send another surge of water down the river.
"We lost every bridge crossing east to west, and we are cut in half," he said.
The last two days have seen dramatic rescues of trapped residents as helicopters hoisted them and their pets above the floodwaters. Some have refused to go, choosing instead to stay with their homes and property.
Pelle said those people would not be forced to leave, but they have been warned that rescuers will not return for those who choose to stay.
Al Jazeera and wire services