The Cause of the Johnstown Flood

by Walter Frank, Civ. Engr.; Baden Sports, Renton, WA,

Serial Information: Civil Engineering—ASCE, 1988, Vol. 58, Issue 5, Pg. 63-66

Document Type: Feature article


The Johnstown flood occurred in 1889, when an earth and rock dam failed during a record rainfall in eastern Pennsylvania. The flood was one of the worst civil disasters in the U.S.; 2,200 people were killed and the town virtually destroyed. The history of the dam's design, rehabilitation and other changes to the structure are described, and their likely contribution to the failure outlined. An argument is put forth that contests the findings of investigations at the time, which found that the original designer of the dam had designed and built the dam without regard to freak storms, and that he did not provide for an adequate spillway. The designer had died by the time of the failure and could not defend himself. This author argues that the dam was constructed differently than the investigators at the time assumed. If the reconstruction of the dam had been built according to the original specifications, the disaster would not have occurred, says the author.

Subject Headings: Floods | Earthfill dams | Failure analysis | Hydraulic design | Dam failures | Rocks | Rainfall | History | Pennsylvania | United States

Services: Buy this book/Buy this article


Return to search