Disaster Responses to Flash Flood

On the night of July 31, 1976, extremely heavy rainfall came to the Big Thompson River Canyon of Colorado. The severe flash flood, which developed in a few hours, claimed 145 lives and caused nearly –40,000,000 in property damage. Several features of the Colorado-Big Thompson water diversion Project, located on the river system, played an important role in preventing even greater damage and loss of life. The project operational alert to the disaster came from the personal observation of heavy rainfall and measurement of flood flow in the Estes Park area. Based upon the observed conditions and best judgment, immediate action was taken to place the Project system into an emergency mode of operation. A broad-scale program of restoration of water and power facilities was initiated on August 1. A critique of the operation provides first hand experience that may be of value to other water resource managers.