Local advice should always be obtained, but if the tidal stream is properly worked, vessels drawing up to 1.80m (the maximum authorised draught on the lateral canal) are generally able to make the passage between Bordeaux and Castets-en-Dorthe. (Lock at access to/from the Canal de Garonne at Castets-en-Dorthe.)ĭraught – Depths are variable and subject to the tides. Now navigation is effectively limited to the tidal river. Only a short length was made navigable through Toulouse after the weir at Le Bazacle mill was raised to supply water to the Canal de la Garonne. History – Commercial navigation extended upstream of Toulouse from the Middle Ages, but the river was never canalised.

It should further be noted that a bore ( mascaret) sometimes forms during low flow periods over a distance of up to 40km upstream from Bordeaux. Navigating the tidal stream presents no exceptional difficulty, but careful attention is required and use of one of the waterway guides covering this river is recommended.

The distance from Castets-en-Dorthe to Bordeaux is 54km, Bec d’Ambès is a further 25km downstream and the length of the Gironde from Bec d’Ambès to the sea is 71km. At Bec d’Ambès the Dordogne enters on the right bank, the river widens considerably and changes its name to Gironde. At the Pont de Pierre in Bordeaux the river becomes a maritime waterway. From this point downstream the river forms part of the main waterway route across southern France from the Atlantic to the Mediterranean. The river becomes fully navigable as a tidal stream at its junction with the Canal de Garonne at Castets-en-Dorthe. Navigation is possible only during moderate floods or in light craft only. From Nicole to Castets-en-Dorthe, a distance of 73km, the shifting channel presents numerous obstacles to navigation, and depths vary considerably. An alternative link to the Lot will eventually have to be provided. The works proved inadequate, however, and no passage can be made during low flows. The river was thus to provide the vital navigable link between the Baïse and Lot navigations. Here the river was made semi-navigable in 1995 by clearing a narrow channel through the sill of marl above the confluence of the Lot. The second section extends from the confluence with the Baïse at Saint-Léger to the junction with the Lot outlet canal at Nicole, a distance of 4.7km. The section in Toulouse is 5 km long and includes one lock. It is navigable as a tidal river, and also in two short sections. The Garonne rises in the Pyrenees and drains a large part of the Aquitaine basin.

Dordogne map detailed