The 1913 Flood

4th Street of Dayton, OH, USA during Great Miami Flood in 1913.

March 21, 1913:
The first of several days' storms arrives, which leads to massive flooding of the Great Miami River valley.

Here's wikipedia:

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.
The Miami River watershed covers nearly 4,000 square miles (10,000 km²) and 115 miles (185 km) of channel that feeds into the Ohio River. Other cities across Ohio experienced flooding from these storms, but not as extensive as the cities of Dayton, Piqua, Troy, and Hamilton along the Great Miami River.
As the water receded, the damages were assessed in the Dayton area.

• More than 360 people died.
• Nearly 65,000 people were displaced.
• Approximately 20,000 homes were destroyed.
• Buildings were moved off their foundations, and debris in the moving water damaged other structures.
• Property damage to homes and businesses, including factories and railroads, were over $100,000,000 (in 1913 dollars or over $2,000,000,000 in today’s dollars).
• Nearly 1,400 horses and 2,000 other domestic animals died.

The Miami Conservancy District undertook a massive project to prevent future flooding.  The work included levee construction and channelization, along with the heart of the plan, five massive dams and detention basins constructed upstream from Dayton.  Here are the details of the dams:

The district manages five dry dams. They are hydraulic fill dams constructed from 1919 to 1921 using fill trestles.

Englewood Dam

Located near Englewood, Ohio, Englewood dam is the largest of the dams maintained by the district. It regulates the flow of the Stillwater River into the Great Miami River. It consists of 3,500,000 cubic yards (2,700,000 m³) of earth, is 110 feet (34 m) high and stretches 4,716 feet (1,437 m). U.S. Route 40 crosses the top of the dam. The dam can contain 209,000 acre feet (258,000,000 m³) of flood water over 6,350 acres (26 km²). It was constructed in 1919 and consists of as much earth as the Great Pyramid of Giza.

Germantown Dam

Located near Germantown, Ohio, Germantown Dam regulates the flow of Twin Creek into the Great Miami River. It consists of 865,000 cubic yards (661,000 m³) of earth, is 100 feet (30 m) high and 1,210 feet (370 m) wide. The dam can contain 73,000 acre feet (90,000,000 m³) of flood water over 2,950 acres (11.9 km²) (12 km²). It was constructed in 1920.

Huffman Dam

Located near Fairborn, Ohio, Huffman Dam regulates the flow of the Mad River into the Great Miami River. It consists of 1,665,000 cubic yards (1,273,000 m³) of earth, is 65 feet (20 m) high and spans 3,340 feet (1,020 m). The dam can contain 124,000 acre feet (153,000,000 m³) of flood water over 7,300 acres (30 km²).

Lockington Dam

Located north of Piqua, Ohio outside the village of Lockington, Ohio, Lockington dam regulates the flow of Loramie Creek into the Great Miami River. It consists of 1,135,000 cubic yards (868,000 m³) of earth, is 69 feet (21 m) high and spans 6,400 feet (2,000 m). The dam can contain 63,000 acre feet (78,000,000 m³) of flood water over 3,600 acres (15 km²) (15 km²). It was constructed in 1919.

Taylorsville Dam

Located near Vandalia, Ohio, Taylorsville Dam regulates the Great Miami River. It consists of 1,235,000 cubic yards (944,000 m³) of earth, is 67 feet (20 m) high and spans 2,980 feet (910 m). When full, the dam would inundate 9,650 acres (39.1 km²) (39 km²). It was constructed in 1919.

This was a massive and damn impressive engineering, construction and political feat.