The plateau de Lannemezan is a plateau

Plateau

In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...

 in Hautes-Pyrénées

Hautes-Pyrénées

Hautes-Pyrénées is a department in southwestern France. It is part of the Midi-Pyrénées region.-History:...

 département, in Pyrenees

Pyrenees

The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain...

 foothills,not far from spain, southwestern France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, with about 10,000 inhabitants.

Its name is due to the city Lannemezan

Lannemezan

Lannemezan is a commune in the Hautes-Pyrénées department in south-western France.-Geography:The Petite Baïse has its source in the commune.Lannemezan is around 30 km east of Tarbes, and around 100 km south-west of Toulouse.-References:*...

, which lies in the middle of the plateau.
The plateau of Lannemezan

Lannemezan

Lannemezan is a commune in the Hautes-Pyrénées department in south-western France.-Geography:The Petite Baïse has its source in the commune.Lannemezan is around 30 km east of Tarbes, and around 100 km south-west of Toulouse.-References:*...

 through 155 years of work (1840-1995)can be considered the water tower across Biscay.The Canal de la Neste along with more than 28 km takes its water from the dam-Beyréde Jumet in Aure Valley laimenté itself by the lakes Massif Néouvielle (Aumar-Aubert-Orédon) and Louron (caillaouas) and ends on the Plateau de Lannemezan through the channel of sludge.

Numerous rivers have their source on the plateau:

• Garonne
  Garonne
  The Garonne is a river in southwest France and northern Spain, with a length of .-Source:The Garonne's headwaters are to be found in the Aran Valley in the Pyrenees, though three different locations have been proposed as the true source: the Uelh deth Garona at Plan de Beret , the Ratera-Saboredo...
  
   basin
  Drainage
  Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...
  
  : Gesse
  Gesse
  The Gesse is a long river in the Hautes-Pyrénées, Haute-Garonne and Gers départements, southwestern France. Its source is at Arné, on the plateau de Lannemezan. It flows generally northeast...
  
  , Petite Baïse
  Petite Baïse
  The Petite Baïse is a long river in the Hautes-Pyrénées and Gers départements, southwestern France. Its source is in Lannemezan, on the plateau de Lannemezan. It flows generally north...
  
  , Gers
  Gers River
  The Gers is a 178 km long river in southern France, left tributary of the Garonne.Its source is in the foothills of the Pyrenees, near Lannemezan. It flows north through the départements Hautes-Pyrénées, Gers and Lot-et-Garonne. It flows into the Garonne near Agen. The city Auch lies along the...
  
  , Save
  Save (Garonne)
  The Save is a 143 km long river in southern France, left tributary of the Garonne. Its source is in the northern foothills of the Pyrenees, south of Lannemezan...
  
  , Gimone
  Gimone
  The Gimone is a 136 km long river in south-western France, left tributary of the Garonne. Its source is in the foothills of the Pyrenees, near Lannemezan...
  
  , Baïse
  Baïse
  The Baïse is a 188 km long river in south-western France, left tributary of the Garonne. Its source is in the foothills of the Pyrenees, near Lannemezan...
  
  , Arrats
  Arrats
  The Arrats is a 162 km long river in southern France, left tributary of the Garonne. Its source is in the northern foothills of the Pyrenees, near Sariac-Magnoac...
  
  , Louge
  Louge
  The Louge is a long river in southwestern France, left tributary of the Garonne. Its source is in the département of Hautes-Pyrénées, near Lannemezan.It flows generally north-northeast through the following départements and towns:*Hautes-Pyrénées:...
  
  , Touch
  Touch River
  The Touch is a long river in southwestern France, left tributary of the Garonne. Its source is in the département of Haute-Garonne, near Lilhac.It flows through the following département and towns:...
  
  , Osse
  Osse River
  The Osse is a long river in southwestern France, right tributary of the river Gélise. Its source is in the Hautes-Pyrénées, southeast of the village Bernadets-Debat, in the Plateau de Lannemezan...
  
  
• Adour
  Adour
  The Adour is a river in southwestern France. It rises in High-Bigorre , at the Col du Tourmalet, and flows into the Atlantic Ocean near Bayonne. It is long, of which the uppermost as the Adour du Tourmalet. At its final stretch, i.e...
  
   basin: Bouès
  Bouès
  The Bouès, is a right tributary of the Arros, at the eastern end of the basin of the Adour, in the Southwest of France.- Geography :The Bouès rises near Capvern, west of Lannemezan where it is fed by the Neste Canal...