Before modern civilization, before ancient civilization, there was...
A Dance of Ice and Stone
Water used to run in the opposite direction in the southernmost part of the Scioto valley. Before the modern Ohio River existed, the Scioto watershed area was drained by the Teays River which rose in North Carolina and flowed north-west through central Ohio. 
The New River of Virginia and West Virginia still flows northward through the gorge of the Teays, beyond the farthest reach of the glaciers. We can only imagine what the Teays valley looked like through central and western Ohio, before the glaciers shaved the hills and filled the valleys. Data from well-drilling suggests the valley was two miles wide and is now buried up to 500 feet under the glacial debris.
The Ohio River formed after the glaciers blocked the Teays to create Lake Tight. It may be difficult to imagine today, but southern Ohio and northern West Virginia and Kentucky were under a lake that stood for thousands of years, filling the tributary valleys and making islands out of ridgetops. Eventually the lake rose high enough to overflow a divide of high ground near Madison, Indiana, beginning the development of the modern Ohio River and offering a lower outlet for drainage. So the flow of the Teays was "stolen" by the Ohio River, including the Teays north of the Ohio, and the Scioto River began to run southward through the same valley that the Teays occupied flowing northward.
Yes, but that was all finished a long time ago...
Somewhere under all the clay and stones left by the glaciers, the old Teays tributary valleys lay buried. (One of them bogged down a tunneling machine for the sewer line project from Dublin to Columbus.) Meanwhile, the Scioto river and its tributaries we see today have formed since then. Today you can see them continuing to cut through the limestone of Franklin County. 
Look at the foot of O'Shaugnessy Dam, and you can see the stones that have dislodged from the East side of the gorge wall, beginning their march downriver. The riverbed is all stones below the dam, and past Dublin's Scioto Park, until the stream flow eases into the top of Griggs Reservoir. The tributary creekbeds are stony. Go to Hayden Falls and you can see where flakes of stone have recently come off the waterfall's face, leaving fresh stone exposed. As Henderson Road crosses Slate Run, you can see the dirt banks washing away as fast as they can.
Stretch your imagination to run time forward for several thousand years, and try to guess what these growing valleys will look like then. The dams we see now will be gone as the earth moves out from beneath them. (Actually, at O'Shaugnessy you can see how large concrete slabs have been installed to replace the missing stone, and the tops of these new structures are littered with ... you guessed it, more moving stone.) Perhaps the modern terrain, so flat that people complain of boredom, will appear only as isolated points of high, level ground among the growing valleys. Or, with enough time, maybe a glacier will wipe it all out again for another re-start.