Thank you all. I tested the formula against an old table that dated bsck to
when the gates were installed in the '70's. That gave the flow over all 8
gates in 2.4 inch increments. The formula gives values only 2% greater. I
wanted a formula that we could use with our automation system.
Here is my actual formula as it will be used:
=(((1000000*B5)/((3*1440*936)*B6))^(2/3))/12
As I said, I'm using a formula for weirs applied to movable gates on a dam.
There are 8 gates, each of them is 78 feet across, and we actually look at
feet of water over the gates.
B5 is the desired MGD
B6 is the number of gates with water going over
"/12" is to convert from inches to feet going over
Thanks again for your help.

"Shawn" wrote:

I have a formula for finding the flow over a horizontal weir. ( gpm = 3 *
weir L ins. * overflow ins. 1.5th) I want to set up an Excel formula to give
the result as the overflow inches. ("X" in "X^1.5") How do I do that?