1. THE TETON DAM FAILURE

2. INTRODUCTION June 5th 1972: Teton Dam Collapses.
Teton Dam is located on the Snake River Plain in southeast Idaho
Total damage cost reached as high $2 billion.
11 people died, 200 left homeless and cattle were destroyed.

3. SITE HISTORY
United States Bureau of Reclamation (USBR) studied 16 different sites between 1932 and 1961.
Settled on Teton canyon and began inspecting site in 1957.
Over 100 borings were taken on site and a report on the geological and seepage conditions deemed the site suitable for dam construction.
USBR awarded Morrison-Knudson the contract to begin construction.
The main aim of the dam was to provide irrigation to surrounding farmlands and HEP.

4. FOUNDATIONS
Section 1: 21m deep trenches with steep sides on the abutments of the 1550m elevation.
Section 2: A cutoff trench to the underlying rock below the 1550m elevation.
Section 3: A grout curtain that ran along the foundations itself.
Section 4: The extraction of the rock located beneath the abutments.

5. DAM COMPOSITION 10 million m³ of material needed to construct Dam.
There were 5 main sections to the Dam:
Section 1: Core: Moisture content 1.5% dry of optimum permeability metres/year.
Section 2: Compacted Sandy Gravel: Overlies Section 1.
Section 3: Miscellaneous Fill: Similar composition to that of Section 1.
Section 4 and 5: Rock Fill: Compacted on outer surface of dam.

6. FAILURE
June 3rd 1976: Small leaks discovered in northern section of the abutment.
June 4th 1976: Areas of dampness and small springs appeared in the right section of the abutment.
June 5th 1976: Major leak with flow rate of litres/second. Seepage occurs 40m below dam crest.
June 5th 1976: A few hours later a whirlpool forms in the reservoir. Shortly after, the Teton Dam Collapses.

7. TETON DAM TAKING A LEAK

10. HOLEy CRAP

14. God DAM that’s a lot of water

15. FLOODING Rexburg, Idaho
Over 300 million m³ of water passes through broken Dam.
Rexburg, Idaho

16. CAUSES Piping failure proved to be main reason for Dam failure.
Piping Failure = “The development of tubular leak-causing cavities”
Poor geological surveying.
Poor construction: Grout Curtain failed thus allowing underlying materials be swept easily downstream

17. CONSEQUENCES 11 people dead 200 people homeless
13,000 cattle destroyed
Surrounding farmland and towns ruined through flooding
Up to $2 billion in total costs through damages and compensation

18. REMAINS OF TETON DAM