THE TETON DAM FAILURE Slide 2 INTRODUCTION June 5 th 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 13000 cattle were destroyed.
Slide 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. Slide 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. Slide 5
DAM COMPOSITION 10 million m 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 0.3 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. Slide
6 FAILURE June 3 rd 1976: Small leaks discovered in northern
section of the abutment. June 4 th 1976: Areas of dampness and
small springs appeared in the right section of the abutment. June 5
th 1976: Major leak with flow rate of 500- 800 litres/second.
Seepage occurs 40m below dam crest. June 5 th 1976: A few hours
later a whirlpool forms in the reservoir. Shortly after, the Teton
Dam Collapses. Slide 7 TETON DAM TAKING A LEAK Slide 8 Slide 9
Slide 10 HOLEy CRAP Slide 11 Slide 12 Slide 13 Slide 14 God DAM
thats a lot of water Slide 15 FLOODING Over 300 million m of water
passes through broken Dam. Rexburg, Idaho Slide 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 Slide 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 Slide
18 REMAINS OF TETON DAM
