Canal de Garonne

Canal latéral à la Garonne
Canal latéral à la Garonne in Puybarban in Gironde Department, France
Specifications
Length	193 km
Maximum boat length	30.65 m (100.6 ft)
Maximum boat beam	5.80 m (19.0 ft)
Locks	53
Maximum height above sea level	128 m (420 ft)
Minimum height above sea level	0 m (0 ft)
History
Construction began	1838
Date completed	1856
Date restored	During 1970s, locks lengthened to 38m
Geography
Start point	Toulouse
End point	Castets-en-Dorthe
Beginning coordinates	43°36′42″N 1°25′06″E / 43.61156°N 1.41827°E / 43.61156; 1.41827
Ending coordinates	44°33′50″N 0°09′20″W / 44.56387°N 0.15546°W / 44.56387; -0.15546
Connects to	Canal de Brienne, Canal du Midi, Canal de Montech, River Garonne, River Tarn

The Canal de Garonne, formerly known as Canal latéral à la Garonne, is a French canal dating from the mid-19th century which connects Toulouse to Castets-en-Dorthe. The remainder of the route to Bordeaux uses the Garonne River. It is the continuation of the Canal du Midi which connects the Mediterranean with Toulouse. Together they and the Garonne River form the Canal des Deux Mers which connects the Mediterranean Sea to the Atlantic Ocean.

The canal runs along the right bank of the Garonne, crosses the river in Agen via the Agen aqueduct, then continues along the left bank. It is connected to the Canal du Midi at its source in Toulouse, and emerges at Castets-en-Dorthe on the Garonne, 54 km southwest of Bordeaux, a point where the river is navigable.

The canal is supplied with water from the Garonne by two sources:

With the exception of the five locks at Montech, bypassed by the water slope, all of the locks have a length of 40.5m and a width of 6m. The locks at Montech are as built, 30.65m long.

More than 100 bridges were built on the canal. Many were rebuilt in 1933 as prestressed concrete bow bridges, to allow for the requirements of larger barges.

The canal has a width of 18 meters at the water level. It has 53 locks, with a total difference in level of 128 meters. Its design depth is 2.00 metres, for a draught of 1.80 metres (although a practical maximum of 1.30 metres, especially at Castets-en-Dorthe, exists as of June 2017). The minimum headroom beneath bridges and other structures is 3.60 metres.

The Canal de Garonne was considered a possibility from ancient times. Before the Canal du Midi was constructed, the passage between the Atlantic Ocean and the Mediterranean Sea was along the Spanish Atlantic coast and through the Strait of Gibraltar. This route, more than 3,000 kilometers long, subjected sailors to the risks of attack and storms.