HydroBASINS lev08 watershed · #2080559860
Bassin du Ciron
A watershed (drainage basin) is not a body of water — it is the land area where rainfall converges towards a single river that eventually reaches the sea (or an endorheic basin). Boundaries follow ridgelines.
Crosses 3 administrative regions : Gironde, Landes, Lot-et-Garonne
Sub-basin area
1 272,2km²
Upstream area
1 272,3km²
Discharge
16,01m³/s
Mean elev.
100m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
3 dept-equivalent regions (GADM L2)
- 965.1 km²75.7% of basin
- 170.0 km²13.3% of basin
- 139.8 km²11.0% of basin
65 communes (GADM L5)Available for FRA, RWA
- Captieux105.60 km²88% commune
- Saint-Symphorien77.50 km²73% commune
- Allons76.00 km²100% commune
- Préchac64.24 km²100% commune
- Maillas60.61 km²95% commune
- Landiras41.81 km²69% commune
- Saint-Michel-de-Castelnau41.75 km²97% commune
- Balizac41.52 km²100% commune
- Lubbon40.55 km²83% commune
- Saint-Léger-de-Balson37.69 km²100% commune
- Lerm-et-Musset36.59 km²100% commune
- Bernos-Beaulac36.54 km²100% commune
- Lucmau33.52 km²49% commune
- Cudos32.87 km²93% commune
- Giscos32.34 km²100% commune
- Bourideys31.80 km²65% commune
- Noaillan31.55 km²100% commune
- Houeillès31.33 km²46% commune
- Uzeste26.27 km²100% commune
- Cazalis25.36 km²54% commune
- Escaudes25.18 km²100% commune
- Losse24.03 km²23% commune
- Origne22.50 km²100% commune
- Budos20.87 km²100% commune
- Saint-Martin-Curton20.16 km²49% commune
- Louchats19.19 km²48% commune
- Léogeats19.16 km²96% commune
- Goualade17.41 km²100% commune
- Sauméjan16.62 km²86% commune
- Marions16.04 km²100% commune
- Lartigue13.43 km²100% commune
- Villandraut12.73 km²100% commune
- Boussès11.34 km²23% commune
- Sauternes11.31 km²98% commune
- Lignan-de-Bazas10.58 km²95% commune
- Pindères9.98 km²24% commune
- Pompéjac9.74 km²100% commune
- Lavazan8.06 km²91% commune
- Guillos7.61 km²34% commune
- Sillas7.48 km²100% commune
- Preignac6.53 km²49% commune
- Pujols-sur-Ciron6.43 km²84% commune
- Bommes5.39 km²100% commune
- Barsac5.08 km²35% commune
- Baudignan4.59 km²20% commune
- Bourriot-Bergonce4.58 km²6% commune
- Marimbault4.36 km²62% commune
- Arx4.33 km²18% commune
- Le Nizan4.06 km²27% commune
- Antagnac3.51 km²38% commune
- Grignols2.86 km²12% commune
- Sauviac2.67 km²24% commune
- Cours-les-Bains2.39 km²24% commune
- Masseilles1.77 km²26% commune
- Cauvignac1.60 km²28% commune
- Illats1.23 km²4% commune
- Pompogne1.08 km²3% commune
- Sore1.06 km²1% commune
- Hostens0.80 km²1% commune
- Le Tuzan0.54 km²3% commune
- Birac0.45 km²4% commune
- Bazas0.27 km²1% commune
- Roaillan0.18 km²2% commune
- Fargues0.12 km²1% commune
- Sendets0.09 km²1% commune
6 intersecting protected areas
Landes De Gascogne
IUCN VRegional Nature Park
527.19 km² overlap
Vallée du Ciron
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
33.80 km² overlap
Champ de tir du Poteau
IUCN Not ReportedSpecial Protection Area (Birds Directive)
25.25 km² overlap
Champ de tir de Captieux
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
16.59 km² overlap
Lagunes de Saint-Symphorien
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.16 km² overlap
La Garonne en Nouvelle-Aquitaine
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
4 274 distinct species · 263 345 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 36 species (selected proportionally per kingdom among those with at least one documented interaction here) to keep the graph readable. Hover for details, click to explore the full ecosystem of a species.
ℹ️ The territory contains many more species than displayed and all their documented interactions: the graph is intentionally the structural skeleton (top-N species by composite local score, edges filtered by Serrano 2009 disparity filter α=0.2).
Indicateurs du tissu écologique
Tissu écologique de Bassin du Ciron : 25 espèces dont 3 patrimoniales (LR IUCN CR/EN/VU) reliées par 121 interactions GloBI sur 6 types (connectance 19.2%, filtre Serrano α=0.2). 11 bulles taxonomiques (cascade genre/famille GloBI, ≥3 espèces).
Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).
Hydroclimate (BasinATLAS lev08)
Mean T°
12,4°C
Annual rain
933mm
Moisture idx (CMI)
-0,05
Runoff
397mm/an
PET
984mm
AET
699mm
Mean slope
0,9°
Water table
133cm
Forest
93%
Crops
5%
Urban
0%
Protected
29%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)