Why must the soil be pre-wetted before timing the final drainage rate measurement in a percolation test?

Answer

To ensure the soil is fully swollen and mimicking conditions after significant rain

Pre-wetting saturates the soil, ensuring it is swollen and simulating the conditions experienced after a heavy rainfall event, providing a realistic capacity reading.

Why must the soil be pre-wetted before timing the final drainage rate measurement in a percolation test?
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