Bulls Bridge at 1 on paint

At 11:30 am this morning, the level was about 1 inch over the block.
At 3:30 pm this afternoon, the level is just a little bit below the block.
http://waterdata.usgs.gov/ct/nwis/uv?site_no=01200500
(images in this post were left large so you can get a closer look at the gauge)

All of the minimum required flow ("Fish Flow") comes from a gate on the side of the canal, just above the head gates.  (See flow at middle-right of picture) Anything that goes over the dam is extra, and starts to make the run more attractive to paddle.  (See flow at top left of picture in main drop of Stairway Rapid)  The painted gauge was worked out so that, during fish flow, the water level would be about 1 unit (not really feet) below the top of the block.  The old schoolers call it "minus one" and the new schoolers call is "zero" or "fish flow".  Either way, the top of the block is 1, and that takes water going over the dam.

The level at 3:30 pm today. Photo taken from middle window in the bridge.

Same gauge, same time (3:30 pm), different view (from river left, by the fence)