Basse river
The Basse is a river in the Pyrénées-Orientales department in the Occitanie region of southern France. It is a right-bank tributary of the Têt, which it joins in Perpignan.
Geography
With a length of, the Basse rises east of the small hill of Serrat del Pou and about 200 metres north of Sainte-Colombe-de-la-Commanderie, southwest of Thuir.Until the end of the 17th century, the Basse joined the Têt near Canet. Its course was then shortened by the construction of a canal by the king's engineers.
At the entrance to Perpignan the river has been channelled to limit flooding. It flows past the Lycée François-Arago and the Castillet, and meets the Têt downstream of the Joffre bridge at an altitude of about.
The Basse frequently experiences floods during heavy rain; its discharge can become significant even within Perpignan, for example opposite the Castillet.
Municipalities and cantons crossed
Within the Pyrénées-Orientales department, the Basse crosses six communes and several cantons:- From upstream to downstream: Sainte-Colombe-de-la-Commanderie, Thuir, Ponteilla, Le Soler, Toulouges, Perpignan.
Drainage basin
The river's drainage basin covers about, whereas the Têt basin is about, meaning the Basse represents under 5% of the total Têt basin.Managing authority
The managing authority is the SMBVT, created in 2008.Tributaries
SANDRE does not list any tributaries. However, Perpignan's environmental baseline report identifies two right-bank tributaries:- The Sagne
- The Ganganell, long, flowing through Toulouges, Canohès and Perpignan. It recorded a flood discharge of on 26 October 1915.
Hydrology
The “Nouvelle Basse” at Perpignan
The Basse was monitored from 1977 to 1991, a period of 14 years, at the station “La Nouvelle Basse à Perpignan ”. The mean discharge over that period was, i.e. after the construction of the flood-diversion canal.Floods
Over the monitored period, the maximum instantaneous discharge occurred on 19 October 1977 at 12:20, with ; the maximum instantaneous water level was, and the maximum daily mean discharge reached.The Têt is known for very large floods, called aiguats in Catalan; the most recent major event dates to 1992 with. The best-known event was the October 1940 flood, reaching.
Flood events recorded on the Basse include the aiguat of 24 August 1842, as well as floods in 1915, 1959 and 1969; in 1959 the discharge reportedly reached.
In 1975, a canal running alongside the A9 autoroute was built to divert flood flows towards the Têt, designed for 50-year floods on the order of. Perpignan thereby avoided flooding on 16 October 1977, 1 March 1986, 16 November 1986 and 26 September 1992.
Development
Within the commune of Toulouges, the Basse is crossed by the Perpignan–Figueres high-speed rail line.Long inaccessible to the public, the banks of the Basse in the urban section through Perpignan are planned to be redeveloped starting in 2026 to allow, in part, pedestrian and cyclist access.