A water cannon in the mining context is a high-pressure water delivery device mounted on mobile or fixed equipment, used to disaggregate, mobilise, and transport unconsolidated ore or overburden materials using powerful jets of water. Water cannons — also known as hydraulic monitors or giants — are particularly associated with alluvial and placer mining operations, where they are used to break down soft, unconsolidated gravel, clay, and sand formations containing gold, diamonds, or other heavy minerals. In alluvial gold mining operations in regions such as West Africa and Southeast Asia, water cannons direct high-velocity jets at ore-bearing gravel banks or hillsides to dislodge material, which is then slurried and directed to sluice boxes or washing plants for gold recovery. In alluvial diamond mining — such as those historically operated in West African coastal deposits — water cannons are used to mobilise diamond-bearing gravels into processing circuits. In bauxite mining, water cannons are sometimes employed in hydraulic mining systems to dislodge soft bauxite and transport it as a slurry to the processing facility. Water cannons are also used for dust suppression on haul roads and in open pits across iron ore and gold mines, reducing airborne particulate matter and improving occupational health conditions for mine workers.
