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A college prank that probably has other names. Most commonly played in college dorms. The act of filling a trash can about halfway with water. Then you lean said trash can against a door. Knock on the door and run like hell. When the sucker goes to open the door, they get the onslaught of the water, going everywhere.

I call it the Johnstown Flood as I attend the University of Pittsburgh at Johnstown, and the name fits perfectly, if you're familiar with the town's history
When you Johnstown Flood someone, don't get caught. The "flood waters" can do some serious damage

Try at your own risk!
by UPJ jack October 17, 2009
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The act of Butt-Chugging a 25oz can of Domestic beer and showering the contents onto your lover over the edge of a table.
I received the best Johnstown Flood of my life last night. We then watched goon and ate pizza rolls. I am in love!
by Jon town December 13, 2017
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