Somewhere between 500 - 600 cfs, they shut off the power plant (and we get all the water)

This screenshot from
https://waterdata.usgs.gov/ct/nwis/uv?site_no=01200500
shows the water being turned off at the power plant.
With the gauge being downstream of the power plant, when the water is turned off the river will drop until water starts flowing over the dam 2 miles upstream. 

I spoke with one person at the power plant on Saturday evening after he closed the head gates at the top of the penstocks.  He said that they did not have enough water to operate and the project will be off until the river  rises.  While he would not reveal the exact threshold for ceasing operation, I recall the same thing happening around 550 cfs last summer. 

The level was a couple of inches below the top of the block at the put in on Saturday.  We can roughly call that 3/4' on the paint. 

Post work day laps on this (forecast) hot week.....