The Dropt basin

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Contents of the page :  the river Dropt  -  The Dropt basin  -  climate  -  searching for the Dropt

The river Dropt

The Dropt (pronounce “dro”) or Drot is an affluent of the right bank of the Garonne, between the Lot up-stream and the Dordogne down-stream. Most important affluents : Bournègue, Banège, Dourdèze, Vignague, for the right bank ; Douyne, Dourdenne for the left bank.

     Map of the Dropt basin (23 k.octets)

The Dropt springs up at the bottom of a 239 metres high hill, in the massif situated between the great valleys of the Lot and of the Dordogne. It flows from east to west from Capdrot (the head of the Drot : “lou cap del Drot” in langue d’oc or “caput Drotii” in Latin) to Caudrot (the tail of the Drot : “la couau del Drot” in langue d’oc or “cauda Drotii” in Latin).

To its natural Caudrot mouth, two Dropt – Garonne links are added : the Escourret branch of Gironde-sur-Dropt (open in 1768 by a sudden rising of the Dropt) and the Casseuil canal with a lock-gate, open during the XIXth century for the navigation needs of the Dropt, up-stream of the last dam before the Garonne.

The very slight slope between its spring and its mouth (150 metres difference in level for 125 km) makes the Dropt a peaceful, winding, open-country river, entirely bordered with trees. From the spring to the junction with the Garonne is a series of dams with their ancient mills, including smaller mills along the affluents.

For agricultural needs (irrigation), reservoir lakes – the Brayssou lake (60ha) at Parranquet, the Ganne Lake (40ha) at Tourliac, the Nette lake (27 ha covered, 1 200 000 m3) at Cavarc, the Graoussettes lake (36 ha) along the Dourdenne at Saint-Colomb-de-Lauzun, the Escourroux lake (112 ha) near Eymet – sustain the water level (much diminished by the harnessing of the Brame spring, near Monpazier, used for water conveyance) and reduce rises in water levels.  

In the XIXth century, the Dropt made a navigable waterway down-stream from Eymet, used for transporting goods. At the time when the great evolution of transport means occurred, the Dropt carried ships from Eymet to its mouth. This activity has completely disappeared. The Eymet “harbour” is well preserved, “Quai de la navigation”.

The Dropt has always suffered from a high demand in water for irrigation. Its slow flow and its morphology make it very sensitive to eutrophisation, brought about by phosphate and nitrate deposits and made worse by long periods of stagnation in the many “biefs” ("bief" : river portion between two consecutive dams). Today, the Dropt is a sick river ; the “jussie”, amphibious plant which proliferates uncontrollably in slow-flowing waters, has been seen in the Dropt. The development plan for controlling water levels should improve this situation.
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The Dropt basin :   

Its basin covers nearly 1 500 km2 in Guyenne, from the Quercy to the Bordelais, borderline with the Haut-Agenais and the “purple” Périgord. Along its first half, the Dropt approximately follows the partition line between the “départements” (counties) of Dordogne and Lot-et-Garonne ; its course finishes in the Gironde. In 1999, the population of the 9 “cantons” (districts) which constitute the Dropt basin was 41 454 inhabitants, about 27,5 inhabitants / km2 (half the population density of the Lot-et-Garonne county). The absence of a town, even only “medium sized”, in the Dropt basin increases the rural character of this region. Miramont-de-Guyenne and Eymet appear as capitals with respectively 3 360 and 2 552 inhabitants… The other “urban centres” reckon with 1 000 to 1 500 inhabitants.

The  Drot (!) between Lot and Dordogne (47 k.octets)

Notice on this ancient map ( Atlas 1922 edition) the spelling “Drot”, which is also found in Capdrot and Caudrot.

The origin, fairly recent (XVIIIth century ?),  of the change in spelling from “Drot” to “Dropt” is unknown.






The alluvial plain in itself is of modest proportions (around 1 km wide at half course). It is in general bordered on either side by "boulbènes" terraces; then come molassic foothills with a few hillocks or the edges of chalky plateaux. The nature of the ground gives the basin its agricultural inclination.

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Climate :

Winter is mild (stark cold and snow are exceptional) and damp (fog and drizzle). 
Spring is the rain season (nearly half the annual precipitations). 
Summer is dry and warm, unpleasant by stormy weather. 
Autumn (October) may be the most pleasant period : still dry, warm, with a beautiful light. Stendhal used to compare the Agenais with Toscany…
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Searching for the Dropt :

  The “Petit Larousse 2000”, the main encyclopaedia (Memo Encyclopédie Larousse, Microsoft Encarta, Encyclopaedia Universalis) ignore the Dropt, in the main text and in the maps !

  The “Petit Robert des noms propres” (dictionary of proper nouns), the « Dictionnaire encyclopédique Hachette », and previous editions of the « Petit Larousse » all confirm : the Dropt exists ! One learns that it springs in South Périgord, goes through Eymet and joins another river down-stream from La Réole (Petit Robert) ; finally, that it is used for irrigation (Hachette).

  But it remains very difficult to spot the Dropt on a geographical map of France (relief and rivers). At best the bed is outlined, but with no name indication ; or else the furrows of the Dropt and its affluents are perfectly visible, but with no line printed (France physique IGN 1 : 2 500 000) ; at worst, nothing is visible…

      Find the  Dropt...(33 k.octets)                      

                        Find the Dropt on this map...
                                     (I.G.N France Physique)

Some reasons for such contempt :
 -     Unfortunately, the Dropt belongs to the group of affluents of the right bank of the Garonne, numerous, coming from the Pyrenees (Ariège) or the Massif Central (Tarn, Lot, Dordogne), long, powerful, of great renown for tourists thanks to the gorges of their upper parts. They have all given their name to a county.
-   The Dropt is a relatively short, flat open country river, unique of its type on this bank ; it crosses no important town, no scenic road runs along it ; the Dropt does not yet exist as a county.

  If only the Dropt flowed on the left bank…

 What if this modesty made its charm…
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