Basse river

For other uses, see Basse (disambiguation).

Basse Agouille de Baillarou
The Arrondissement of Perpignan in the Pyrénées-Orientales department.
Physical characteristics
Source	Serrat del Pou (234 m)
• location	Sainte-Colombe-de-la-Commanderie
• elevation	180 m
Mouth	Têt
• location	Perpignan
• elevation	26 m
Length	16 km
Basin size	70 km2
Discharge
• location	Perpignan
• average	0.656 m3/s
Basin features
Progression	France
River system	Têt
Tributaries
• left	None
• right	La Sagne; Ganganell
Managing authority	SMBVT (Syndicat Mixte du Bassin Versant de la Têt)[1]

The Basse (La 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 16 km (9.9 mi), the Basse rises east of the small hill of Serrat del Pou (234 m (768 ft)) and about 200 metres north of Sainte-Colombe-de-la-Commanderie, southwest of Thuir.^{[2][3][note 1]}

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.^[4]

At the entrance to Perpignan the river has been channelled (partly lined with concrete) to limit flooding. It flows past the Lycée François-Arago and the Castillet (a former fortified gate of Perpignan), and meets the Têt downstream of the Joffre bridge at an altitude of about 26 m (85 ft).

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:^{[2][note 2]}

• From upstream to downstream: Sainte-Colombe-de-la-Commanderie, Thuir (source area), Ponteilla, Le Soler, Toulouges, Perpignan (confluence).

In cantonal terms, the Basse rises in the canton of Thuir and then crosses the cantons of Millas, Toulouges, Perpignan-8, Perpignan-6, before joining the Têt in the Perpignan-2, all within the Arrondissement of Perpignan.

Drainage basin

The river's drainage basin covers about 70 km² (27 sq mi)^[5], whereas the Têt basin is about 1,417 km² (547 sq mi) (or 1,369 km² (529 sq mi) according to SANDRE^[2]), meaning the Basse represents under 5% of the total Têt basin.

Managing authority

The managing authority is the SMBVT (Syndicat Mixte du Bassin Versant de la Têt), created in 2008.^[1]

Tributaries

SANDRE does not list any tributaries. However, Perpignan's environmental baseline report identifies two right-bank tributaries:^[5]

• The Sagne (right-bank)
• The Ganganell (right-bank), 7 km (4.3 mi) long, flowing through Toulouges, Canohès and Perpignan. It recorded a flood discharge of 70 m³/s (2,500 cu ft/s) on 26 October 1915.^[6]

The river's Strahler number is therefore 2.

Hydrology

The “Nouvelle Basse” at Perpignan

The Basse was monitored (by the Banque Hydro) from 1977 to 1991, a period of 14 years, at the station “La Nouvelle Basse à Perpignan (pont autoroute)”.^[7] The mean discharge (module) over that period was 0.656 m³/s (23.2 cu ft/s), 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 88.9 m³/s (3,140 cu ft/s); the maximum instantaneous water level was 175 cm (69 in), and the maximum daily mean discharge reached 36.50 m³/s (1,289 cu ft/s).^[7]

The Têt is known for very large floods, called aiguats in Catalan; the most recent major event dates to 1992 with 1,115 m³/s (39,400 cu ft/s). The best-known event was the October 1940 flood, reaching 3,600 m³/s (130,000 cu ft/s).

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 240 m³/s (8,500 cu ft/s).^[5]

Bridge over the Basse river, in Perpignan

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 300 m³/s (11,000 cu ft/s). 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.^[8]

Ecology

The Basse forms a “green corridor” crossing western Perpignan and provides attractive habitat for birds.^[5]

See also

• Perpignan
• Têt

Notes and references

Notes

1. According to the municipality of Perpignan, the source would be at Roc de Majorque (440 m (1,440 ft)), less than 2 km (1.2 mi) east of Serrat del Pou.
2. SANDRE (2011) does not list the commune of Sainte-Colombe-de-la-Commanderie, but instead Canohès, which borders the Aguilla (irrigation canal, or agouille) of Ballaro and the Perpignan canal.

References

1. "Le SMBVT ou Syndicat Mixte du Bassin Versant de la Têt". bassintet.fr (in French). Retrieved 6 November 2015.
2. "La Basse (SANDRE: Y0470560)". SANDRE (Service d'administration nationale des données et référentiels sur l'eau) (in French). Retrieved 29 August 2019.
3. Géoportail – IGN. "Géoportail" (in French). Retrieved 13 November 2011.
4. de Roux, Antoine (1996). Perpignan de la place forte à la ville ouverte (in French). Perpignan: Archives communales de Perpignan. p. 499. ISBN 2-909444-03-1.
5. mairie-perpignan. "Titre II : État initial de l'environnement" (PDF) (in French). Retrieved 13 November 2011.
6. Praca, Edwige. "La crue du 26 octobre 1915 à Perpignan" (in French). Retrieved 6 August 2018.
7. "La Nouvelle Basse à Perpignan (pont autoroute) – Station Y04755620". Banque Hydro (in French). Retrieved 13 November 2011.
8. David, François (24 June 2025). "Les berges de la Basse bientôt accessibles aux piétons et aux cyclistes à Perpignan". francebleu.fr (in French). Retrieved 4 August 2025.

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