How to Measure a Pond
Measuring pond length and width
Usually you will be measuring the pond at the high water mark to determine the maximum capacity. You can also measure the dimensions of the pond at various levels to make calculations more accurate when using the pond drop method. This might be essential if the pond slope is not uniform.
Sight down the pond and place a mark on the pond bank at the average of the water line. Do this for the opposite side of the pond as well. Using a wheel or a tape, measure between the two marks.
Measuring pond side slope
Be sure to follow appropriate safety precautions when working around dairy lagoons. Use a lifeline and have a helper nearby.
Measure the length of a run, or horizontal distance, that is long enough to accurately capture the variation of the slope. The horizontal measure must be level, which can be difficult to tell when you are in the pond and can't see the horizon. Use a level taped to a rigid pipe or board, or a line level on a string.
Measure the vertical (rise) and horizontal (run) distance from the pond bank to at the point where the two lengths meet.
Measuring rise and run with a level taped to a board of known length.
Measuring rise and run with a line level on a string. The length of the string from the bank to the junction needs to be recorded along with the rise.
Here a worksheet where you can record your pond dimensions for several common pond shapes.