How do I calculate the number of gallons in my pond?

Approximate Gallons of Water in a POND
Length x Width x 80% x Avg. Depth x 7.48 = total gallons
*The basin takes up approximately 80% of the actual SQ. FT.

Approximate Gallons of Water in a STREAM
(Length x Width x .25 (Depth) x 7.48) = Gallons in the stream.
*You need 2x the amount of water in your basin