The combination of topographic and climatic factors in the Tulsa, Oklahoma area have frequently caused major flash flooding, especially near streams that normally drain the area. The city was founded atop a bluff on the Arkansas River. Thus, elevation protected most of the inhabitants and their possessions from damage when the river flooded. However, by the turn of the 20th Century the population growth had moved closer to the river, and the flatlands west of the Arkansas had begun to develop as well. The floods typically caused widespread property damage and sometimes death. By the 1920s, seasonal floods of the Arkansas began to cause serious damage and loss of life. Since its founding, city leaders had responded to such events by simply rebuilding and replacing the property that had been