The August 1956 Flood: On a Friday afternoon in late August, the water level rose approximately five feet within minutes, sweeping away equipment and beach sand. Cause: New York City had opened blow-off gates at the Croton Dam for inspections. Engineer John H.

Kelly claimed, "Our man wasn't aware that a beach had been developed by Croton." NYC officials had visited Silver Lake in February but failed to notify about the gate opening. Black Rock, a private upstream club, received advance warning. The next morning, staff conducted recovery in 40-45°F water, removing the diving board, children's slide, and lifeguard chair. Swimming remained closed for the rest of that season.