“The man on the surface uses his pole to dislodge stones so the outflow can run freely down the sluice into which the gold-bearing pay dirt is meant to settle.”

“Ashore a spume of brine water rains from an overhanging crag and sluices back through the beach.”

“These are then used to keep the cruiser steady as water sluices out of the lock.”

“Locally the sluices and waterways from the flood plain to the river are in several cases clogged up.”