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On June 9, 1972, one of the most devastating floods in the nation's history swept through Rapid City, South Dakota, and nearby communities. More than 10 inches of rain fell in just over six hours, producing flooding on Rapid Creek and several other Black Hills streams. The swollen streams rushing toward Rapid City and the failure of Canyon Lake Dam combined to send a wall of water through the community.

By daybreak on June 10, 1972, the disaster left 238 people dead and over 3000 injured. Memorial Park, a large park in the center of Rapid City with a small lake, flower gardens, fountain and a memorial with names of the 238 people was created in tribute to those who perished.

Although there have been many floods recorded since settlement of the Black Hills, the 1972 flood was especially destructive. Extraordinary weather conditions have been blamed for the storm that sent torrents of rain over the Black Hills that night. Heavily saturated soil from previous rains and a stationary front that poured inches of rain in a few hours resulted in extreme run-off and the swollen streams. Many weather experts refer to the 1972 flood as a hundred-year flood. Evidence of very large prehistoric floods ("paleofloods") in the Black Hills exists, including at least two that exceeded the 1972 flood, about 440 and 1,000 years ago.

The damage to Rapid City was extreme. The 1973 U.S. Senate Subcommittee on Disaster Relief estimated the cost of physical destruction in excess of $100 million and approximately 3,100 acres of land were affected by the flood water and fires from ruptured gas lines within Rapid City.

To prevent a re-occurrence of this tragedy the city of Rapid City established a floodplain. A beautiful greenway and bike path now meander through the city alongside the once destructive Rapid Creek. In 2007, the city of Rapid City formed a Floodplain Development Policy Committee to address citizen concerns about development in the floodplain.