Four people have lost their lives in flooding this week that has engulfed swaths of Colorado and that has forced thousands to evacuate their homes.

Udall, director of the University of Colorado, Boulder’s Getches-Wilkinson Center for Natural Resources, Energy and the Environment says that the Boulder area (see map) has received more rain in the past three days (up to 15 inches, or 38 centimeters) than the previous precipitation record for a whole month.