Kyle Schuler, left, carries his pregnant sister with the help of his father, Kim Schuler, right, after gathering belongings from their flooded home on
Kyle Schuler, left, carries his pregnant sister with the help of his father, Kim Schuler, right, after gathering belongings from their flooded home on Upland Avenue in Boulder on Friday during the heavy flooding. (JEREMY PAPASSO)

Federal crews began a historic search and rescue effort Friday as 181 people in Boulder County remain "unaccounted for" following 100-year flooding from several days of torrential rainfall.

Two Federal Emergency Management Agency teams joined the effort Friday. With 250 people, the largest federal search and rescue team ever for the state of Colorado is now tasked with scouring a flood-ravaged Boulder County.

"This is an unprecedented event," Sheriff Joe Pelle said.

The death toll rose Friday to at least three after crews found a woman who had been missing since Thursday morning.

Evacuations issued late Thursday for western central Boulder, Eldorado Springs and portions of Longmont remained in effect Friday night.

The list of people who are "unaccounted for" -- who can't be reached by family and friends -- has also grown from 20 on Thursday to 181, and Pelle said he expects the number to rise even more because most of the western part of the county is still inaccessible.

"I expect that list to grow," Pelle said. "The things that worry us are what we don't know. We don't know how many lives are lost, we don't know about homes lost."

Emergency officials are keeping that list confidential for now. However, emergency officials Friday morning said every person on the list is an adult, and University of Colorado officials said no students are unaccounted for.

Weather conditions improved enough for the National Guard to send helicopters into Jamestown to evacuate the town and drop off supplies. At the same time, residents of Lyons are also being evacuated into Longmont by high-clearance National Guard vehicles.

'It's not safe right now'

Many major highways have been re-opened, but other roads and highways -- including Table Mesa Drive at Broadway -- remain closed, and Boulder police spokeswoman Kim Kobel asked people to stay out of Boulder if possible and off the roads.

Boulder Mayor Matt Appelbaum signed an emergency declaration making it illegal for people to be on the city's open space and mountain parks land. Kobel said flooding in those areas has made them dangerous.

"There are lakes in Boulder where there weren't lakes before," Kobel said. "It's not safe right now."

Police also said tubing, boating or kayaking in a disaster area is illegal.

A break in a pipe of the wastewater treatment plant also resulted in a 300-foot breach of untreated sewage water to flow directly into Boulder Creek on Friday evening, though it has not affected Boulder's drinking water.

At the University of Colorado, about 355 residents were allowed to return to faculty and staff housing units, Athens Court and the ground floor of Newton Court, after being evacuated Thursday.

CU Chancellor Phil DiStefano announced Friday that today's football game against Fresno State will be postponed. While Folsom Field is structurally OK, the university said it did not want to divert resources from relief efforts.

The storm system has dumped a record-shattering 14.71 inches of water on the Boulder area since Monday. Average yearly precipitation is just under 21 inches.

Midnight scare, evacuations

Late Thursday, a caller told dispatchers he had heard an "explosion" from the area of Emerson Gulch in Fourmile Canyon and saw the valley below him fill with water carrying debris, including cars. He estimated the wall of water to be about 30 feet high.

Officials told residents to prepare for a surge and ordered evacuations from the mouth of Boulder Canyon east to Broadway, between Marine and Pearl streets. They were told to evacuate on foot to avoid getting trapped in their cars on streets that were running like rivers.

Residents east of Broadway along the creek all the way to 75th Street were told to "shelter in place" but move to higher floors or higher ground if possible.

A U.S. Geological Survey water gauge in Fourmile Creek recorded a 17-foot wall of water slightly before midnight, but the feared surge did not materialize, perhaps because the water spread out in the wider floor of Boulder Canyon.

Contact Camera Staff Writer Mitchell Byars at 303-473-1329 or byarsm@dailycamera.com.