An earth dam is a relatively simple construction for being a marvel of old school engineering. By layering wet earth and giving it time to settle and dry before applying more, a mound of earth, sloped on both sides at a ratio of twice as long as high, can hold back millions of tons of water. With one caveat. The water must never run over the center of the dam or the entire dam will erode in seconds.
The dam at South Fork, in Pennsylvania, was properly designed to create a canal, which was made immediately obsolete by a completed rail that allowed trains to make the same route. It was abandoned. Until 1880 when oil tycoons from Pittsburgh decided on the area for an exclusive resort. They filled the lake and stocked it with fish.
An earth dam includes safety features to prevent a catastrophic breach of the dam’s center: pipes underneath to control water flow, a spillway lower than the breast of the dam to allow overflow to run off the sides. The pipes were no longer functional when the oil tycoons of Pittsburg filled the lake with more water than the dam was originally designed to hold. Too many of the fish they’d brought in were being lost through the spillway, so they installed a guardrail, which besides blocking fish blocked debris which blocked water. They also lowered the dam to make it wide enough for a road so they could cross back and forth.
The Titanic sunk on April 15th, 1912 with 2224 people on board. Everyone knows the story of the precious few lifeboats being reserved for the first class passengers. Human arrogance played a role in that disaster as the “virtually unsinkable” ship was rushed across icy waters. Yet one of the reasons the story of the Titanic has endured is that rich and famous people, the tabloid fodder of the day, went down with the ship. 1502 people perished.
On May 31st, 1889, a days-long heavy rain was finally letting up. The valley was flooded just by the rains, but flood town psychology made it something of an embarrassment to flee to higher ground because of a few feet of water. It seems eerily prophetic to read that a woman, earlier that day, had told anyone who would listen that the great flood was coming and everyone was going to die, except she said that every time it rained.
Some of the smaller towns up the Conemaugh valley were warned of what was coming or spared the flood’s full torrent, not Johnstown. Witnesses would describe the wall of debris, trees and homes and buildings, pushed in front of the water, as an explosion. Homes were there one second, gone the next. Clothes were torn off people’s bodies. Some people rode for miles on rooftops and were eventually rescued. Others never knew what hit them and were buried in the muck. The flood shoved everything in its path against a stone bridge, where the wreckage burned all night. Survivors clung to debris. Many were rescued but some couldn’t be reached and were left to hope the water caught them before the fire.
2209 people perished in the flood. David McCullough’s excellent account of the disaster, The Johnstown Flood, ends with a memorial listing the names and ages of the victims. After experiencing the details of this tragedy, I was left compelled to peruse the list and mourn for them. I also took a day trip to the site and took some pictures I’ll upload to facebook.