Email, John W. Kangas, U.S. secretary, International Niagara Committee, Nov. 18, 2013

Here is how I figured it:

1. Jan, Feb, Mar, Nov, Dec: 151 days at 50,000 cfs times 24 h/day (multiply out to get cfs-hours) 2. Apr, May, Jun, Jul, Aug, Sep 1 -15: 168 days times (14 hours @100,000 cfs + 10 hours @50,000 cfs) 3. Sep 16-30, Oct: 46 days times (12 hours @100,000 + 12 hours @50,000 cfs) Add these up, divide by 365, divide by 24 hours and you end up close to 66,600 cfs.

The 100,000 cfs can be related to what a tourist sees going over the falls in the summer.