June 9 will mark the 50th anniversary of the Rapid City Flood.  Citizens throughout South Dakota will be commemorating that tragic day when 238 lives were lost. This once-in-every-500-years flood is said to have been the most destructive flash flood in U.S. history.  

The Lives lost included three guardsman, three firefighters, seven airmen from Ellsworth Air Force Base, one police reserve officer and other rescuers. There are still five missing. Three thousand fifty-seven people were injured. There were 1,300 homes destroyed, of which 500 were mobile homes, 2,800 homes were damaged, along with 5,000 vehicles, and 36-150 businesses were destroyed, depending on the resource. The total cost of these damages was $165 million; $1.1 trillion in 2022 dollars. 

On June 9, 1972, several, almost stationary, thunderstorms produced extremely heavy rainfall in the Rapid Creek watershed between Pactola Lake reservoir and Rapid City.  These storms are said to have dumped nearly 15 inches of rain in six hours near Nemo. An average of two to six inches/hour.  In a 60 square mile area, more than 10 inches of rain fell onto soil already saturated due to earlier rains.  The loosened soil caused trees to be easily uprooted and float down Rapid Creek.  This debris clogged the spillway and put pressure on the Pactola Dam.  The dam failed.  Between the water from Pactola Lake and the rainwater flowing through the tributaries of Rapid Creek, a flash flood was created.  At one point, the creek reached a height of over 15 feet and became six blocks wide. This occurred during the night while many people were retiring for the evening or already asleep. 

Fortunately for the flood victims, 1,800 South Dakota National Guard were in the Rapid City area for their summer encampment at Camp Rapid on the westside of the city. Was it a coincidence or divine intervention? The Guardsmen’s mission switched from being one of training to one of rescue, recovery and cleanup. With the use of bulldozers, cranes, trucks and other equipment, they worked heroically throughout that fateful night to serve and save lives. These soldiers continued to serve for days and weeks afterward as they helped with the enormous clean-up efforts.  The number of casualties would have been much higher had it not been for the efforts of the highly professional and highly courageous guardsmen.  

…Read on in this week’s issue of the Sanborn Weekly Journal!