An important component of quantifying bedload transport flux is the identification of the onset of bedload motion. Bedload transport can be monitored with high temporal resolution using passive acoustic methods, e.g., hydrophones. Yet, an efficient method for identifying the onset of bedload transport from long-term continuous acoustic data is still lacking. Benford’s Law defines a probability distribution of the first-digit of datasets and has been used to identify anomalies. We apply Benford’s Law to the three years of acoustic recordings from a stationary hydrophone in the Taroko National Park, Taiwan. Our workflow allows for monitoring bedload motion in near-real-time, and it is convenient for others to reference. Two bedload transport events were identified during the examined period, lasting 17 and 45 hours, accounting for approximately 0.35% of the time per year.