But dealing with a deluge like this one remains a very personal experience, as illustrated by the photos shared with us by Longmont's Bill May.
In images and his captions for them, he takes viewers from his home to the immediate area, depicting the impact on the places he visits. Join him below.
May adds: "Closer to the mountains, the flooding creeks have closed off roads and isolated areas. All the canyons ( Boulder, Left Hand, North and South St. Vrain) are all closed and emergency help can't get up them. The city of Lyons has been isolated for two days and the National Guard are using large Army trucks to haul out people that need medical help."More from our News archive: "Videos: Trapped Lyons residents being evacuated by National Guard."