Ohio River

===River depth===
[[File:Lawrenceburg-indiana-from-above.jpg|thumb|[[Lawrenceburg, Indiana]], is one of many towns that use the Ohio as a shipping avenue.]]
The Ohio River is a naturally shallow river that was artificially deepened by a series of [[dam]]s. The natural depth of the river varied from about {{convert|3|to|20|ft|m|0}}. The dams raise the water level and have turned the river largely into a series of [[reservoir]]s, eliminating shallow stretches and allowing for commercial navigation. From its origin to Cincinnati, the average depth is approximately {{convert|15|ft|m|0}}. The largest immediate drop in water level is below the McAlpine Locks and Dam at the [[Falls of the Ohio National Wildlife Conservation Area|Falls of the Ohio]] at [[Louisville, Kentucky]], where flood stage is reached when the water reaches {{convert|23|ft|m|0}} on the lower gauge. However, the river's deepest point is {{convert|168|ft|m|0}} on the western side of Louisville, Kentucky. From Louisville, the river loses depth very gradually until its confluence with the Mississippi at [[Cairo, Illinois]], where it has an approximate depth of {{convert|19|ft|m|0}}.

Water levels for the Ohio River from Smithland Lock and Dam upstream to Pittsburgh are predicted daily by the [[National Oceanic and Atmospheric Administration]]'s Ohio River Forecast Center.<ref>{{cite web |url=https://www.weather.gov/ohrfc/ |title=Ohio RFC |publisher=US Department of Commerce, NOAA, National Weather Service |access-date=March 10, 2017 |archive-date=March 12, 2017 |archive-url=https://web.archive.org/web/20170312072122/https://www.weather.gov/ohrfc/ |url-status=live}}</ref> The water depth predictions are relative to each local flood plain based upon predicted rainfall in the Ohio River basin in five reports as follows:

* [[Pittsburgh|Pittsburgh, Pennsylvania]], to [[Hannibal Locks and Dam]], Ohio (including the Allegheny and Monongahela rivers)
* [[Willow Island Locks and Dam]], Ohio, to [[Greenup Lock and Dam]], Kentucky (including the Kanawha River)
* [[Portsmouth, Ohio]], to [[Markland Locks and Dam]], Kentucky
* [[McAlpine Locks and Dam]], Kentucky, to [[Cannelton Locks and Dam]], Indiana
* [[Newburgh Lock and Dam]], Indiana, to [[Golconda, Illinois]]
The water levels for the Ohio River from Smithland Lock and Dam to Cairo, Illinois, are predicted by the [[National Oceanic and Atmospheric Administration]]'s Lower Mississippi River Forecast Center.<ref>{{cite web |url=http://www.weather.gov/lmrfc/ |title=Lower Mississippi RFC |publisher=US Department of Commerce, NOAA, National Weather Service |access-date=March 10, 2017 |archive-date=February 28, 2017 |archive-url=https://web.archive.org/web/20170228181631/http://www.weather.gov/lmrfc/ |url-status=live}}</ref>
* [[Smithland Lock and Dam]], Illinois, to [[Cairo, Illinois]]

{{wide image|PennsylvaniaRailroadBridgePanorama.jpg|5000px|Panorama of the Ohio at its widest point, just west of downtown Louisville, Kentucky|700px|center}}