For anyone interested in how the new (bigger) locks use less water than the old locks (reclaiming 60% of the water - without pumps!), this old Practical Enginee

For anyone interested in how the new (bigger) locks use less water than the old locks (reclaiming 60% of the water - without pumps!), this old Practical Engineering video explains with diagrams: https://www.youtube.com/watch?v=SBvclVcesEE https://www.youtube.com/watch?v=SBvclVcesEE They store the water in a series of basins at different levels, and use those basins to fill the portion of the lock below. It's more obvious with diagrams.