Which measurement is crucial for calculating the perc rate in inches per minute?

The crucial measurement for calculating the perc rate in inches per minute is the time taken for water to drop from a specific height, such as from 12” to 9”. The percolation rate is determined by recording how long it takes for water to descend a certain distance in the soil. This time measurement is critical because it provides a direct correlation between the rate of water movement through the soil and the percolation rate expressed in inches per minute.

Specifically, the calculation involves taking the distance the water level drops—as in this case, 3 inches—and dividing it by the time taken for that drop. This provides a rate of percolation, which is essential for assessing soil drainage capabilities. Without accurately measuring the time needed for the water to drop, calculating the perc rate accurately would not be possible.