KUSA - Approximately 1,000 people in Larimer County are waiting to be rescued, according to emergency officials.
Type 2 Rocky Mountain Incident Management Team commander Shane Del Grosso said many people have made requests for evacuation.
Sunday's rain grounded airlifts, as rescuers search for ways to rescue those in isolated areas by ground.
The Larimer County Sheriff's Office says an 80-year-old woman missing from Cedar Cove is presumed dead. She was injured in her home and not able to leave when the flood waters rose.
When neighbors arrived to check on her, the house was gone. She is the second person presumed dead in the county due to the deadly floods.
A 60-year-old Cedar Cove woman who was reported missing was presumed dead on Saturday.
The primary focus of the Larimer County Sheriff's Office on Sunday is to save lives and assess conditions.
The county expects an additional two to four inches of rain on Sunday to exacerbate flooding conditions.
Sunday there were a total of 16 helicopters helping with evacuations and taking emergency personnel to the areas that need help.
Crews are still trying to contact the 473 people who are still unaccounted for in the area. They are not considered missing; they have not been able to be reached by friends or family members at this time.
Additional helicopters are now in the county to help with the search and rescue.
FEMA Search and Rescue will help as well in Big Thompson Canyon.
Several days of nonstop rain caused flows in rivers to surge as many as 100 times normal levels, peaking between Thursday night and Friday morning. Forecasters saw the storm coming, but what it became was hard to believe.
(KUSA-TV © 2013 Multimedia Holdings Corporation)