In the cities of Columbus and Dublin, the river has cut a gorge in fossil-bearing Devonian limestone, and many tributary streams have waterfalls, such as Hayden Falls.

[6] In 2012, the river dropped to record- or near-record-low water levels as a result of the acute effects of the 2012 North American drought in Ohio.

Farther upstream, at Shawnee Hills, the O'Shaughnessy Dam was built in 1922–1925 creating a larger reservoir which was billed at the time as "the finest inland waterway in the United States."

[8] The $35.5 million removal project was initially proposed in the 2010 Strategic Plan for downtown Columbus and was funded by a coalition of public and private entities.

Prior to its demolition, the Main Street Dam impounded roughly 2.3 miles (3.7 km) of the Scioto River, artificially enlarging its width to an average of 500 feet (150 m) in downtown Columbus.

Once completed, the Scioto Greenways project will reduce the width by nearly half, and expose 33 acres (13 ha) of land which will be reclaimed as parkland by the city.

Experts believe the restoration project will result in a healthier river and better habitat for native plant, fish, and mussel species.