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How to Measure a Pond in Gallons

Finding the volume of an irregularly shaped object is difficult, especially when you can clearly see only two of its three dimensions. Such is the case with a body of water like a pond. Though you can take a fairly accurate measurement of its length and width, figuring the average depth can be trickier, especially when you don't know all of the contours of the bottom of the pond. By using a depth finder and the industry standard for average depth, calculating the amount of gallons in a lake can be done with a reasonable degree of accuracy.

Things You'll Need

Personal watercraft
Depth finder
Digital pedometer
Measuring tape
Calculator

Instructions

- 1
  Measure the axes that most closely adhere to the average length and width of the pond. Measure at the water line using your measuring tape or, if the pond is too large, your digital pedometer. Find fixed points close to the lake to denote the start and end points of your walk for both dimensions. Walk in as straight a line parallel to the two axes as possible. Be sure to measure in feet.
- 2
  Take a measurement of the water's depth, with your measuring tape, of the center of the pond or, if the pond is too large, use your depth finder.
- 3
  Multiply the maximum depth of the pond by 0.4 to get a rough measurement of the average depth of the pond.
- 4
  Multiply the average depth of the pond by the average length of the pond. Multiply your result by the average width of the pond to get the volume of the pond in cubic feet.
- 5
  Divide the cubic feet by 7.4805 to determine the number of gallons in the pond.

Nature