Meterology - Big Thomspon Flood of 76' Mrs. Tuorto Fall 2019 Presentation

The Big Thompson Canyon Flood:

The Deadliest Disaster in Colorado History

By Sergio Villar

2019 - Fall - Meteorology - Tuorto

Flooding has always been the deadliest natural disaster. It has impacted many areas around the world and is regarded the most fatal of natural disasters. No matter how beneficial it first was to farmers (silt for growing crops effectively), floods can get out of hand.

When more water falls than can be regulated by the soil or reservoirs, overflowing occurs and water spills out in an uncontrolled and hectic manner. 

The waterfall from storm surges, tsunamis, and thawing snow can easily result in several inches to feet of water, which, when flowing, can easily move aside cars and loose objects, endangering lives. 

Fluvial - An occurrence taking place when water levels from a river, lake, or stream rise and overflow. This overflow can damage other river flows, in the sense that streams may pick up power and destroy dams, thus leaving all surrounding to be submerged. Flat land will flood at a much slower rate, while floods occurring in sloped (downstream, hillside) will flow and travel in minutes.

Pluvial - The flooding can occur WITHOUT a major (or even without any) source of water (rivers, banks of water, ponds) Surface: Drainage system overwhelming = Leakage of water at a SLOW but DAMAGING rate

Flash Floods: Intense rainfall that is dangerous because of debris and speed (pressure) of water 

Coastal - Windstorms/Tsunamis cause coastal flooding. Windstorms during high-tide = devastating damage and losses of life. Strength, size, speed, direction, etc. are all important parts in determining the severity and imminent danger from the coastal floods. Older flood records may be studied to determine danger. 

The Thompson Flood

On July 31st of 1976, when the sky darkened and the clouds formed, no one expected an impending disaster. In a matter of less than 4 hours, a record 12 inches of rain was dropped from the skies, leading to a 20-foot-high wall of water cascading down the mountain sides and absolutely demolishing everything in its’ path. Clouds piled as high as 12 miles into the sky and let forth one of the greatest rainfalls in modern history. The waters rapidly descended the V-shaped canyon and swept up debris (propane tanks, cars, huge boulders). An estimated 3,500 people were camping, fishing, and hanging around the canyon area (reference: the Coloradoan), and in turn, 144 lives were lost to the flood waters. The deceased include children as young as 2 and the elderly as well. Many brave police officers lost their lives in their efforts to securely evacuate people trapped or unaware of the impending flood.

The following Sunday morning of August 1st, hundreds of people needed to be helicoptered out of the newly flooded, and very dangerous, land. The following days were sad, dreary, and emotional ones, as families gathered at local hospitals looking for the bodies of their deceased and missing loved ones. 

Although many lives were lost in the devastating and unprecedented flood, the lives lost were not forgotten. On the 25th anniversary of the flood, 2001, a Stone Memorial was placed near Drake, Colorado, in memoriam of the 144 who lost their lives. Yearly, families come out to the canyon to remember those who they lost in somber silence, loving communion, or solemn emotion. 

Now, safety regulations in case of floods have obviously grown and there are now markers in several locations for safety purposes.