A swivel assembly for use with a water gun mounted on a base or coupled to a water supply conduit to discharge a high velocity stream of water into a mineral stockpile and slurry pit, the swivel assembly comprises a stationary swivel section and a rotatably swivel section configured and disposed to operatively support a bearing including a stationary bearing section and a rotatable bearing section therebetween to facilitate rotation of the water gun relative to the base or the water supply conduit to selectively control the direction of the high velocity stream of water relative to the mineral stockpile.