2. France's current waterway network

Before looking at the most recent stages in the development and modernization of France's river network, it's worth recalling that there are two very different types of navigation situation.

• Navigation on rivers can be either free-flowing, as on part of the Rhine, which requires the waterway manager to ensure that the draught is sufficient to keep the boat or pushed convoy off the bottom, if necessary, with regular dredging and monitoring of bathymetry, or regulated by navigation dams that can be manoeuvred to adapt to the flow of the river, and at the same time equipped with a lock to bypass the dam, or even passes that can be navigated at very high water levels, as well as fish-passing devices.

• Navigation on canals requires a large number of locks delimiting the navigation reaches and a water supply system,...