...where would you put a day's worth of river water?
Random internet search shows that a small river flows at about 1000 cubic feet per second, which is about 30 cubic metres; that's three million cubic metres in a day, which is three million tonnes (water is so convenient). The biggest supertankers can carry about 300,000 cubic metres, so you'd need ten of them...
"...where would you put a day's worth of river water?"
The other side of the river, by diverting all the water down the falls. River flows certainly vary by more than half in this part of the country/world (I'm in Michigan but it's not so different), so if you do it during a down time of the year you would not be creating a flow the rest of the river bed could not handle.
I'm not saying this is a "good" idea but it isn't a bad one in the sense you're suggesting. There is a place to put the water.
Random internet search shows that a small river flows at about 1000 cubic feet per second, which is about 30 cubic metres; that's three million cubic metres in a day, which is three million tonnes (water is so convenient). The biggest supertankers can carry about 300,000 cubic metres, so you'd need ten of them...