HydroBASINS lev08 watershed · #2080561360
Bassin du Tolzac
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 1 administrative regions : Lot-et-Garonne
Sub-basin area
870,6km²
Upstream area
50 335,5km²
Discharge
602,87m³/s
Mean elev.
82m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin du Lot329 km²
- Bassin de Ruisseau de Bénac75 km²
1 dept-equivalent regions (GADM L2)
- 872.4 km²100.0% of basin
79 communes (GADM L5)Available for FRA, RWA
- Marmande38.58 km²85% commune
- Tonneins35.19 km²100% commune
- Monbahus31.80 km²100% commune
- Gontaud-de-Nogaret29.73 km²100% commune
- Puymiclan26.12 km²100% commune
- Montastruc25.70 km²100% commune
- Seyches24.16 km²96% commune
- Puch-d'Agenais23.38 km²100% commune
- Monclar23.11 km²96% commune
- Verteuil-d'Agenais22.75 km²100% commune
- Anzex22.40 km²96% commune
- Le Mas-d'Agenais20.93 km²100% commune
- Grateloup-Saint-Gayrand20.54 km²100% commune
- Leyritz-Moncassin20.09 km²99% commune
- Virazeil18.32 km²94% commune
- Villefranche-du-Queyran17.12 km²100% commune
- Tombebœuf17.08 km²89% commune
- Varès16.83 km²100% commune
- Coulx16.58 km²100% commune
- Calonges16.17 km²100% commune
- Saint-Barthélemy-d'Agenais16.02 km²100% commune
- Fargues-sur-Ourbise15.44 km²34% commune
- Brugnac14.67 km²100% commune
- Pinel-Hauterive14.38 km²67% commune
- Fauillet14.29 km²100% commune
- Moulinet14.28 km²97% commune
- Birac-sur-Trec13.91 km²100% commune
- Laparade12.95 km²80% commune
- Caubeyres12.35 km²87% commune
- Caumont-sur-Garonne11.90 km²100% commune
- Tourtrès11.25 km²100% commune
- Fourques-sur-Garonne11.23 km²79% commune
- Labretonie11.21 km²100% commune
- Villeton11.08 km²100% commune
- Clairac11.05 km²33% commune
- Cancon10.98 km²44% commune
- Sénestis10.79 km²100% commune
- Monheurt10.32 km²93% commune
- Villebramar10.21 km²100% commune
- Lagruère9.93 km²100% commune
- Sainte-Gemme-Martaillac9.42 km²67% commune
- Saint-Léon9.20 km²97% commune
- Hautesvignes8.95 km²100% commune
- Beaugas7.58 km²33% commune
- Fauguerolles7.39 km²100% commune
- Saint-Pardoux-du-Breuil7.30 km²100% commune
- Razimet7.25 km²100% commune
- Damazan7.22 km²44% commune
- Castelmoron-sur-Lot6.90 km²29% commune
- Taillebourg6.85 km²100% commune
- Monviel6.27 km²100% commune
- Montignac-Toupinerie6.19 km²82% commune
- Saint-Pastour5.94 km²41% commune
- Ségalas5.36 km²43% commune
- Laperche5.35 km²64% commune
- Pompiey5.16 km²26% commune
- Beaupuy5.14 km²64% commune
- Agmé4.92 km²100% commune
- Peyrière4.88 km²59% commune
- Longueville4.86 km²100% commune
- Montignac-de-Lauzun3.55 km²17% commune
- Nicole3.41 km²74% commune
- Sainte-Bazeille2.62 km²12% commune
- Labastide-Castel-Amouroux2.40 km²19% commune
- Gaujac2.36 km²33% commune
- Armillac2.35 km²30% commune
- La Réunion1.93 km²7% commune
- Sainte-Marthe1.47 km²15% commune
- Saint-Maurice-de-Lestapel1.26 km²16% commune
- Ambrus1.19 km²10% commune
- Saint-Léger1.12 km²19% commune
- Escassefort0.89 km²6% commune
- Miramont-de-Guyenne0.80 km²5% commune
- Grézet-Cavagnan0.05 km²0% commune
- Lachapelle0.04 km²1% commune
- Saint-Colomb-de-Lauzun0.03 km²0% commune
- Aiguillon0.02 km²0% commune
- Casteljaloux0.01 km²0% commune
- Lougratte0.00 km²0% commune
8 intersecting protected areas
La Garonne en Nouvelle-Aquitaine
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
8.82 km² overlap
Garonne Et Section Du Lot
IUCN IVBiotope Protection Order
6.67 km² overlap
L'Ourbise
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
3.72 km² overlap
Biotope Protection Order
3.68 km² overlap
Étang De La Mazière
IUCN IVNational Nature Reserve
0.70 km² overlap
Protected perimeter around a national nature reserve
0.34 km² overlap
vergers de villebramar
IUCN IVLand acquired by a regional conservatory of natural areas
0.02 km² overlap
coteau de pinel
IUCN IVLand acquired by a regional conservatory of natural areas
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 877 distinct species · 184 723 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 40 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 Tolzac : 35 espèces + 5 bulles famille, 84 interactions GloBI documentées sur 5 types (connectance 10.8%, filtre Serrano α=0.2). Les 5 bulles regroupent des espèces visuellement absorbées par famille (≥3 espèces visibles).
Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).
Hydroclimate (BasinATLAS lev08)
Mean T°
12,5°C
Annual rain
826mm
Moisture idx (CMI)
-0,17
Runoff
339mm/an
PET
992mm
AET
672mm
Mean slope
2,6°
Water table
170cm
Forest
7%
Crops
91%
Urban
3%
Protected
2%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)