High Quality Content by WIKIPEDIA articles! The Great Dayton Flood of 1913 flooded Dayton, Ohio, and the surrounding area with water from the Great Miami River, causing the greatest natural disaster in Ohio history. In response, Ohio passed the Vonderheide Act to allow the Ohio state government to form the Miami Conservancy District, one of the first major flood control districts in Ohio and the United States. This also inflicted a domino series of events, resulting in a further disruption. The flood was created by a series of three winter storms that hit the region in March 1913. Within three days, 8-11 inches of rain fell throughout the Great Miami River watershed on frozen ground, resulting in more than 90% runoff that caused the river and its tributaries to overflow. The existing series of levees failed, and downtown Dayton experienced flooding up to 20 feet (6.1 m) deep. This flood is still the flood of record for the Great Miami River watershed, and the amount of water that passed through the river channel during this storm equals the flow over Niagara Falls each month.