Hurricane Camille hit the Mississippi Gulf coast on Aug. 17,1969, thrashing communities with a tidal storm surge nearly three stories high and winds of up to 200 miles an hour. Or so experts think — it’s hard to say, since the storm destroyed all of the wind recording instruments in the region. When the storm had moved on, many homes were underwater or on fire, and 143 people in Alabama, Mississippi and Louisiana were dead. But Camille wasn’t done.

As the storm moved north, it grew weaker until August 19, when what was left of Camille collided with another system of wet air by the Blue Ridge Mountains. The result was a storm of immense magnitude that took rural Nelson County, Virginia, completely by surprise. Stefan Bechtel explains in his book Roar of the Heavens, small communities in the mountains of central Virginia were inundated with “one of the heaviest rainfalls ever recorded on earth” — in some areas an estimated 31 inches of rain fell in less than eight hours.

“Humans, animals, trees, boulders, houses, cars, barns, and everything else were swept away in a fast-moving slurry, a kind of deadly earth-lava that buried everything in its path,” Bechtel writes. Birds drowned in the trees, people struggling to stay alive had to cover their mouths from the rain to breathe, homes floated away or were crushed by debris. An estimated 2,000 years of erosion of the mountains took place in one night. As rivers rose, flash-flooding occurred all over Virginia, and in Nelson County alone 153 people died, many of their bodies never recovered.

This storm event was known as “probable maximum precipitation.” Thomas Leahy has recently come to learn a lot about PMP storms, and he’s read all about Camille’s wrath on Nelson County. 

. Leahy is director of Public Utilities for the city of Virginia Beach. His interest was piqued in 2007 when he heard about plans to build a uranium mine and mill just south of Nelson County in Pittsylvania County, Virginia. An intake valve for one of Virginia Beach’s main sources of drinking water sits downstream from Pittsylvania County. What would happen to our water, he wondered, if there was a uranium mine and mill in the path of a PMP storm?