HOOVER DAM: What Happens to the American West If It Ever Breaks
Vanished Worlds
22,506 views
Nine trillion gallons. One crack. The people on the bridge above Hoover Dam have four seconds before the sound reaches them. Below them, seven hundred and twenty-six feet of concrete are opening, and the largest reservoir in the United States is turning toward the gap.
Hoover Dam is not one wall. It is the top rung of a ladder of seven, and twenty-five million people drink from the water it holds. So what happens to Las Vegas, Phoenix and Los Angeles when the lake comes through? Why would the earth dam sixty-seven miles downstream dissolve in an hour? What are the two pipes at Lake Havasu, and why would Los Angeles go dry instead of drowning? What really happened in the summer of 1983, when plywood boards were the only thing standing between Lake Powell and the top of Glen Canyon Dam? Why are the flood maps for Hoover Dam no longer public? And how did the Colorado River, with no dam to break, once walk off its course and create a sea in the California desert?
This is a full reconstruction of the failure, wall by wall, from the first crack in Black Canyon to the Salton Sea, and then the other ending nobody films: a lake that is now 26% full and falling toward the line where the dam stops working at all.
Chapters:
0:00 What If Hoover Dam Broke?
2:10 Four States, Two Countries, One Wall
3:39 The First Seconds at the Powerhouse
6:42 Why Arch Dams Fail: The 1928 Lesson
8:19 How Hoover Dam Was Built
10:12 The Lake Fills, Earthquakes Begin
12:59 Down Black Canyon to Davis Dam
18:23 Parker Dam and Lake Havasu's Two Pipes
22:30 Blackout, Silent Pumps and the Imperial Valley
25:27 The Summer of 1983: Spillways and Plywood
29:49 Drought and Lake Mead's Bathtub Ring
32:31 How the Salton Sea Appeared in 1905
35:54 The Flood Ends in a Dying Sea
39:07 The 1922 Deal That Overdrew the River
40:31 Lake Mead Today: 26% Full
42:53 Hoover Dam Today and What Was Real
Main sources:
Carder, D. S. (1945). Seismic investigations in the Boulder Dam area, 1940–1944, and the influence of reservoir loading on local earthquake activity. Bulletin of the Seismological Society of America, 35(4) — reservoir-induced earthquakes under Lake Mead, including the 1939 magnitude 5 event.
Rogers, J. D. (1995). A man, a dam and a disaster: Mulholland and the St. Francis Dam. Southern California Quarterly, 77(1/2) — the 1928 failure, timeline and death toll.
Independent Panel to Review Cause of Teton Dam Failure (1976). Report to U.S. Department of the Interior and State of Idaho on Failure of Teton Dam — how an earthfill dam dissolves in hours.
Falvey, H. T. (1990). Cavitation in Chutes and Spillways. Engineering Monograph No. 42, U.S. Bureau of Reclamation — the 1983 spillway damage at Glen Canyon and Hoover, cavitation mechanics and the aeration fix.
Cory, H. T. (1913). Irrigation and river control in the Colorado River delta. Transactions of the American Society of Civil Engineers, 76 — first-hand engineering account of the 1905–1907 breach and its closure by the Southern Pacific.
Sykes, G. (1937). The Colorado Delta. American Geographical Society Special Publication 19 — geography of the below-sea-level basin and the birth of the Salton Sea.
Hundley, N. (2009). Water and the West: The Colorado River Compact and the Politics of Water in the American West. University of California Press — the 1922 compact and the overallocation of the river.
Udall, B., & Overpeck, J. (2017). The twenty-first century Colorado River hot drought and implications for the future. Water Resources Research, 53(3) — flow decline and the long-term outlook for Lake Mead.
U.S. Bureau of Reclamation, Lower Colorado Basin Region (2026). Lake Mead daily elevation records and 24-Month Study, September 2026 — current lake level, storage and dead pool elevation.
Stevens, J. E. (1988). Hoover Dam: An American Adventure. University of Oklahoma Press — construction, cooling pipes, diversion tunnels and worker deaths.
20 Comments
1 earthquake& it breaks!
HOOVER DAM: What Happens to the American West If It Ever Breaks
Vanished Worlds
22,506 views
Nine trillion gallons. One crack. The people on the bridge above Hoover Dam have four seconds before the sound reaches them. Below them, seven hundred and twenty-six feet of concrete are opening, and the largest reservoir in the United States is turning toward the gap.
Hoover Dam is not one wall. It is the top rung of a ladder of seven, and twenty-five million people drink from the water it holds. So what happens to Las Vegas, Phoenix and Los Angeles when the lake comes through? Why would the earth dam sixty-seven miles downstream dissolve in an hour? What are the two pipes at Lake Havasu, and why would Los Angeles go dry instead of drowning? What really happened in the summer of 1983, when plywood boards were the only thing standing between Lake Powell and the top of Glen Canyon Dam? Why are the flood maps for Hoover Dam no longer public? And how did the Colorado River, with no dam to break, once walk off its course and create a sea in the California desert?
This is a full reconstruction of the failure, wall by wall, from the first crack in Black Canyon to the Salton Sea, and then the other ending nobody films: a lake that is now 26% full and falling toward the line where the dam stops working at all.
Chapters:
0:00 What If Hoover Dam Broke?
2:10 Four States, Two Countries, One Wall
3:39 The First Seconds at the Powerhouse
6:42 Why Arch Dams Fail: The 1928 Lesson
8:19 How Hoover Dam Was Built
10:12 The Lake Fills, Earthquakes Begin
12:59 Down Black Canyon to Davis Dam
18:23 Parker Dam and Lake Havasu's Two Pipes
22:30 Blackout, Silent Pumps and the Imperial Valley
25:27 The Summer of 1983: Spillways and Plywood
29:49 Drought and Lake Mead's Bathtub Ring
32:31 How the Salton Sea Appeared in 1905
35:54 The Flood Ends in a Dying Sea
39:07 The 1922 Deal That Overdrew the River
40:31 Lake Mead Today: 26% Full
42:53 Hoover Dam Today and What Was Real
Main sources:
Carder, D. S. (1945). Seismic investigations in the Boulder Dam area, 1940–1944, and the influence of reservoir loading on local earthquake activity. Bulletin of the Seismological Society of America, 35(4) — reservoir-induced earthquakes under Lake Mead, including the 1939 magnitude 5 event.
Rogers, J. D. (1995). A man, a dam and a disaster: Mulholland and the St. Francis Dam. Southern California Quarterly, 77(1/2) — the 1928 failure, timeline and death toll.
Independent Panel to Review Cause of Teton Dam Failure (1976). Report to U.S. Department of the Interior and State of Idaho on Failure of Teton Dam — how an earthfill dam dissolves in hours.
Falvey, H. T. (1990). Cavitation in Chutes and Spillways. Engineering Monograph No. 42, U.S. Bureau of Reclamation — the 1983 spillway damage at Glen Canyon and Hoover, cavitation mechanics and the aeration fix.
Cory, H. T. (1913). Irrigation and river control in the Colorado River delta. Transactions of the American Society of Civil Engineers, 76 — first-hand engineering account of the 1905–1907 breach and its closure by the Southern Pacific.
Sykes, G. (1937). The Colorado Delta. American Geographical Society Special Publication 19 — geography of the below-sea-level basin and the birth of the Salton Sea.
Hundley, N. (2009). Water and the West: The Colorado River Compact and the Politics of Water in the American West. University of California Press — the 1922 compact and the overallocation of the river.
Udall, B., & Overpeck, J. (2017). The twenty-first century Colorado River hot drought and implications for the future. Water Resources Research, 53(3) — flow decline and the long-term outlook for Lake Mead.
U.S. Bureau of Reclamation, Lower Colorado Basin Region (2026). Lake Mead daily elevation records and 24-Month Study, September 2026 — current lake level, storage and dead pool elevation.
Stevens, J. E. (1988). Hoover Dam: An American Adventure. University of Oklahoma Press — construction, cooling pipes, diversion tunnels and worker deaths.