Page "Canal" Paragraph 24

When a section of the canal needs to be sealed off so it can be drained for maintenance stop planks are frequently used.

These consist of planks of wood placed across the canal to form a dam.

They are generally placed in pre existing grooves in the canal bank.

On more modern canals, " guard locks " or gates were sometimes placed to allow a section of canal to be quickly closed off, either for maintenance, or to prevent a major loss of water due to a canal breach.