Lot (river)

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Lot
Olt
Lot (rivière) .png
Data
Water code FR :  O --- 0150
location France , Occitania and Nouvelle-Aquitaine regions
River system Garonne
Drain over Garonne  → Atlantic Ocean
source Massif Central , in the municipality of Le Bleymard
44 ° 30 ′ 50 ″  N , 3 ° 46 ′ 47 ″  E
Source height approx.  1272  m
muzzle at Aiguillon in the Garonne Coordinates: 44 ° 18 ′ 52 "  N , 0 ° 20 ′ 4"  E 44 ° 18 ′ 52 "  N , 0 ° 20 ′ 4"  E
Mouth height approx.  23  m
Height difference approx. 1249 m
Bottom slope approx. 2.6 ‰
length 485 km
Catchment area 11,400 km²
Left tributaries Bramont , Dourdou de Conques , Riou Mort , Diège , Boudouyssou
Right tributaries Colagne , Boralde de Saint-Chély-d'Aubrac , Boralde Flaujaguèse , Truyère , Célé , Thèze , Lémance , Lède
Medium-sized cities Cahors , Villeneuve-sur-Lot
Small towns Mende , Fumel
Navigable in sections from Port d'Agrès
The Pont Valentré bridge over the Lot in Cahors

The Pont Valentré bridge over the Lot in Cahors

The Lot [ lɔt ] (in the Occitan language: Olt ) is a river in southwest France that runs through the regions of Occitania and Nouvelle-Aquitaine .

geography

It rises on Mont Lozère , in the Massif Central , in the municipality of Le Bleymard , generally drains in a westerly direction and after 485 kilometers flows into the Garonne as a right tributary at Aiguillon . The river meanders strongly in its course.

On its way the river crosses or touches the following departments and larger towns:

In the Occitania region

In the Nouvelle-Aquitaine region

Hydrology

The catchment area is 11,400 km². The amount of water carried is very much dependent on the seasonal rainfall. A time series over 64 years from 1937 to 2000 is available for the gauge in Villeneuve-sur-Lot. The measuring point covers the largest part of the catchment area with 10,900 square kilometers.

In Villeneuve the mean annual discharge is 151 m³ / s, the monthly mean values ​​are between 32.5 m³ / s in August and 289 m³ / s in February. In particularly dry years, the runoff can temporarily (for a maximum of three days) fall below 10 m³ / s. The highest discharge during the measurement period was 2450 m³ / s on December 4, 1976.

During floods, the water level of the Lot, especially in the upper reaches to the mouth of the Truyère, can rise very quickly - by around one meter per hour - and cause great damage. The highest water levels in the last 100 years were measured on March 4, 1927, which was also the largest flood since 1783. The most recent flood occurred in December 2003, which led to considerable escalation, especially in the lower reaches.

shipping

Tow path at Bouziès

The first weirs along the Lot were built in the 16th century to power mills. Some of these mills still exist today, for example the Coty Mill in Cahors. The weirs were with a floodgate provided so as to pass talfahrende vessels or floats with the flow. Ascent ships had to be pulled over the weir with ship winches.

Around 1670, the royal finance minister Jean Baptiste Colbert had 14 chamber locks built between Cahors and Villeneuve . The locks did not yet have gates, but were closed on both sides with oak beams. An old lock of this type has been preserved in Luzech .

In 1821/22 the general director for roads and bridges, Louis Becquey , had a law decided to build and expand numerous canals and rivers in order to cross France with a network of waterways. In addition, he defined a minimum size of 30.40 meters in length, 5.20 meters in width and 1.20 meters in draft , which had to be observed for all locks. The Lot was also one of the rivers developed according to this standard: 76 new locks were built in the 1840s, which finally made the river navigable over a length of 297 kilometers between the mouth at Nicole and Moulin-d'Olt near Decazeville . To shorten the numerous meanders of the river, three ship tunnels were built in Capdenac , Montbrun and Cajarc . The particularly narrow loop of Luzech was crossed by a short branch canal. A towpath ran along the entire navigable route, only partially preserved today. A section between Saint-Cirq-Lapopie and Bouziès , where the towpath is an open gallery in a rock face, is particularly spectacular .

Shipping on the Lot was now mainly used to transport iron and coal from the industrial area of ​​Decazeville. With the construction of the railway lines from Monsempron-Libos to Cahors (1869) and from Cahors to Capdenac (1884), however, Lot shipping soon faced significant competition. Another setback was the decline of the formerly large and respected wine-growing region of Cahors as a result of the phylloxera crisis at the end of the 19th century, as wine was no longer a traditional transport item. With the First World War , shipping on the Lot ended. In 1926 the Lot was removed from the list of navigable waterways by government decree.

Since the locks were no longer maintained, some of them fell into disrepair, unless they were converted for the construction of hydropower plants. It was not until 1990 that the gradual restoration for sport and leisure shipping began. There are now four sections of the Lot that are not connected to each other.

Shipping areas on the Lot
  • Upper Lot (Lot amont): Between Luzech and Saint-Cirq-Lapopie in the Lot department, a 65-kilometer section with 14 locks has been navigable since 1990. In 2007 it was extended upstream to Larnagol by three locks to a length of 74 kilometers. On this section all locks except one are operated by hand.
  • Lower Lot (Lot aval): The lower course in the Lot-et-Garonne department was opened in 2001 between Nicole and Villeneuve-sur-Lot and has since been extended to Saint-Vite. The 72-kilometer section has six automatic locks, some of which have been completely rebuilt.
  • Three locks near Puy-l'Évêque were restored in 2006. A 44-kilometer section with 11 locks between Soturac and Albas has been navigable since 2014 .
  • In 2012, another 34-kilometer section between Port d'Agrès and Bouillac went into operation in the Aveyron department .

The connection of the various navigable sections is planned. However, there are significant technical problems in the way. Two large barrages have to be overcome at Fumel and Luzech, and the former branch canal in Luzech was filled in in 1946. The three former ship tunnels are also used today as feed lines to hydropower plants.

From 2003 to 2017, the Lot again had a navigable connection with the other waterways of Aquitaine. At Nicole you came to the Garonne, which you followed about 5 km upstream and left again at Saint-Léger , where the Baïse flows into it. This was also the route to the Garonne Lateral Canal ( Canal latéral à la Garonne ). It was only possible to cross the Garonne when the water level was normal. Because the maintenance was too expensive, the Lot-et-Garonne department stopped operating the connection at the end of 2017.

Tributaries

Left tributaries:

Right tributaries:

Places on the river

Economy and tourism

Cahors and Vins d'Entraygues et du Fel wines are grown on its banks, and plums in particular are grown on the lower reaches .

In the upper reaches east of Mende, the Lot offers sometimes difficult white water . Further downstream it develops into a canoe hiking river.

literature

Web links

Commons : Lot  - collection of pictures, videos and audio files

Individual evidence

  1. ↑ a b geoportail.fr (1: 16,000)
  2. ↑ a b The information on the length of the river is based on the information about the Lot from SANDRE (French), accessed on September 7, 2009, rounded to full kilometers.
  3. ↑ Station O8481520 - Le Lot Villeneuve-sur-Lot (Synthèse) , accessed August 9, 2012 (French).
  4. ↑ La crue de la Garonne en mars 1927.
  5. ↑ zone réhabilitée à la navigation du bief d'Orgueil au bief de Castelfranc. (PDF) March 2015.
  6. ↑ Remise en navigabilité partial du Lot. (PDF) May 2015.