Unlike many flood-prone areas, Wooster is not surrounded by any large rivers. Indeed, the Killbuck Creek -- the major stream that flooded -- is only about 15 meters (50 feet) across when it reaches Wooster. If the streams of Wooster are relatively small, why can such damaging floods occur?
The geology of the Wooster area offers an explanation. Anyone viewing a topographical map of Wooster will quickly notice a long, flat valley to the west and south of the city, following the Killbuck Creek. The creek itself is bounded by shallow banks.
The “Killbuck Valley,” as it is known, is the direct result of past glacial activity. Between 19,000 and 20,000 years ago during a time geologists call the “Last Glacial Maximum,” glaciers covered Wayne County and were responsible for ‘carving’ the valley. When the glaciers of the period retreated, they left masses of sediment called moraines that blocked off rivers and formed a lake1. The former lake floor forms much of the low-lying areas to the south of Wooster.
In the present day, as in 1969, this flat area is home to many farms and crops that can be dramatically affected by flooding. Particularly in the month of July, it is usually too late to replant crops and too early to harvest them. Crops that are left in the fields during floods can be affected by soil and nutrient erosion as well as bacterial infection that can cause devastating losses for farmers2. July floods, such as the 1969 flood and another in 1946, can thus be particularly devastating3.
1- William P. Cross, "The Flood of June 1946 In Wayne and Holmes Counties, Ohio," Water Resources Board (Columbus, Ohio), March 1947, p. 26 2- Soil Science Society of America, Farming after the Flood, https://www.soils.org/files/science-policy/caucus/briefings/farming-after-flood.pdf 3- Cross, "Flood of June 1946," p. 17.