Pond Boss Forums INTRO Questions & Observations New pond volume question

Oh boy, Math!

IF it is a perfect circle with a 40 ft diameter, the surface area would be

A=pi * R * R, with R= 1/2 D = 20 ft, which works out to about 1257 sq. ft.

An acre is (this is how I remember it; there is of course a large exact number of sq. ft. but it's easier for me to remember it's almost exactly...) a perfect square 209 ft on a side, or about 43,680 sq. ft.

Therefore IF you have a circular pond, it's area is about 1257/43,680 = 0.029 acre.

Proviso: The farther the pond is from being a perfect circle, the more "off" this estimate will be. For example, if it were a square 40 feet on a side, the area would be D * D = 1600 sq. ft. If it were an ellipse with a major (long) diameter of 40 feet and a minor (short) diameter of 30 feet, IIRC the area would be about pi * R1 * R2 = pi * 20ft * 15 ft = 942 sq. ft.

Many times we base stocking numbers on area alone, assuming depth is sufficient (and your 9 feet max depth sounds good to me), although that is usually with larger ponds; in your case considering the volume may be quite prudent.

Volume will be the area times the AVERAGE depth (less than 9 feet), which you will have to estimate based on how steep the sides drop off to 9 feet from the edges. This will get you the estimated volume in either cubic feet or acre-feet, and from that point someone else will have to help convert to gallons if that is what you want your answer in.