Earlier quoted context omitted.
I am not sure of your Hoover discharge figures. St Lawrence is about 17,000 cubic meters per second. Hoover is far far smaller about 3,300 cubic meters per second. St Lawrence is over 5 times as large. You may have mixed up cubic meters/feet?
At least from Wikipedia's numbers, 17K m3/sec. average flow in the St. Lawrence is only found below the mouth of the Saguenay River - far downstream from the Great Lakes, effectively at sea level (vs. even Lake Ontario is ~70m higher), and (from other sources) well downstream of the point where substantial tides and salt water intrude from the Atlantic. I used the spillway capacity of Hoover Dam, rather than try to a…
Well, the flow varies as you reach the source, being about 7,000 M3/sec as it exits Lake Ontario.
In any event, my intent is to have a tolerable degree of outflow diverted from the great lakes, esp in flood years during the melt, when many downstream areas are flooded when the melt is compressed in time by 2 hot spring weeks. Aquifers can be recharged at many permeable perimeters points and the Ogallala aquifer https://en.wikipedia.org/wiki/Ogallala_Aquifer
Has a number of places in it's East and North East that can be used as recharge areas.
As you see from the wiki, it has been drawn down for decades.
Canadians are full of 'not one drop' fanatics - who would prefer to see it go to the Atlantic - flooding each spring, along the way - instead of helping the US drought.
My feeling is the peak snow melt could be diverted to the South and West towards suitable recharge points to mitigate this drawdown - it will take years to build and years to work, but in the end it needs to be done. The forces of warming climates over the next 50 years could make the great plains into the Great US central desert - where nothing either lives or grow. It is a bleak prospect, but we screwed the earth and we must live through it - one way or another - wetter is better.