|Storm Total Rainfall:||~7.5"|
Little was found regarding historic floods in Delaware prior to the 1913 flood. There is an account of a 1904 flood which reached just over 16 feet, with the historic flood stage at Delaware being 9 feet.
With the drainage of the Olentangy River above Delaware being only about 350 mi2, the river response time in heavy rain prior to the installation of Delaware Lake could be potentially rapid. This certainly was the case in the 1913 flood, with the river rising from about 5.5 feet the morning of March 24th to a crest of 27.5 feet by the late afternoon of March 25th. At the present gauging station now 4 miles upstream of Delaware, this equates to a 25.5’ river level.
The 1913 rate of rise at Delaware was about 22 feet in just over 24 hours, and the crest being 11 feet higher than any crest in recent memory for a 1913 Delaware resident. Such extreme flooding left over 200 families homeless and resulted in 18 deaths. As with so many other areas of Ohio, Delaware County lost 41 bridges, including all bridges through the city of Delaware.
The U.S. Army Corps of Engineers completed the Delaware dam in 1948. Located 4 miles upstream of the city of Delaware, the operation of the dam is to keep the Olentangy River within the city of Delaware to below 9 feet. In the event of a 1913 type rainfall with similar existing conditions with Delaware dam in place, there would still likely be flooding in Delaware, though significantly less than what was experienced in 1913.