The balancing of incoming and outgoing water allows the

Canal du Midi The Canal du Midi (; ) is a long canal in Southern France (). Originally named the ''Canal Royal en Languedoc'' (Royal Canal in Languedoc) and renamed by French revolutionaries to ''Canal du Midi'' in 1789, the canal is considered one of the g ...

to operate as it does. Each time a lock operates, large quantities of water are either required to fill it or dump from it into the lower level

pound Pound or Pounds may refer to: Units * Pound (currency), various units of currency * Pound sterling, the official currency of the United Kingdom * Pound (mass), a unit of mass * Pound (force), a unit of force * Rail pound, in rail profile * A bas ...

. There must be a constant source of water in order to fill and the excess water dumped must have a place to exit the canal without it overflowing. Being able to provide this water source was one of the most important problems to be solved by

Pierre Paul Riquet Pierre-Paul Riquet, Baron de Bonrepos (; 29 June 1609 (some sources say 1604) – 4 October 1680) was the engineer and canal-builder responsible for the construction of the Canal du Midi. Early life Born as Paul Riquet in Béziers, Hérault, Fran ...

, its creator. In the canal's original configuration of 1687, water was provided by the

Rigole de la plaine The critical feature of the Canal du Midi was to provide sufficient water to ensure that the lock system continued to function, even through the summer months. The first part of this endeavor was the ''rigole de la plaine'' (). It carried water f ...

from the

River Sor A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

and from the

Bassin de Saint-Ferréol The Bassin de Saint-Ferréol (Languedocien dialect, Languedocien: ''Lac de Sant Ferriòl'') was created as the result of a large earth dam across the mouth of the valley of Laudot stream at St. Ferréol in the Montagne Noire. It was originally pro ...

. The Bassin de Lampy was added later. Since the drought of 1989–1990, water can also be made available from the Lac de Montbel. Water leaving the canal between locks, will exit through either a

weir A weir or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the water level. Weirs are also used to control the flow of water for outlets of l ...

() or a

siphon A siphon (; also spelled syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in an inverted "U" shape, which causes a liquid to flow upward, abo ...

(). Leaving through the

, the water simply flows over the side of the canal via a stone or concrete ledge. If the water reaches a specific level, it may be siphoned off via a stone

Notes

: Distance in km from the beginning of the canal in

Toulouse Toulouse (, ; ; ) is a city in southern France, the Prefectures in France, prefecture of the Haute-Garonne department and of the Occitania (administrative region), Occitania region. The city is on the banks of the Garonne, River Garonne, from ...

References

{{Reflist

External links

CanalMidi.com

The Canal du Midi - "Seuil de Naurouze"
Canal du Midi

See also

Notes

References

External links