The town is bisected by a tributary of the Gave de Pau, the Luz Creek (15.2 km in France) and its tributaries:
A tributary of the Beez (which in itself is a tributary of the Gave de Pau) also runs through the town: the Landistou Creek (12.5 km in France) and its tributaries:
The town is also traversed by the stream of the Fountain MesplĂ©, and its tributary, the stream of Subercase.
The name Lys appears as Lis-Sainte-Colomme (Lily Saint Colomme) from the 1721 census. The name comes from Gascony, and means 'flat land'.
Lys was formerly an annex of Sainte-Colome until it acquired municipality status on January 2, 1858.
Francis Laur has served as mayor since 1995, and is currently serving his third term, which will last until 2014.
The town is part of six intercommunal structures:
The town's economy is primarily oriented toward agriculture and livestock (sheep, cattle, pigs, mules).
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