HydroBASINS lev08 watershed · #2080021860
Bassin de la Sienne
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 2 administrative regions : Calvados, Manche
Sub-basin area
763,7km²
Upstream area
763,7km²
Discharge
19,17m³/s
Mean elev.
115m
Administrative coverage
2 dept-equivalent regions (GADM L2)
- 717.0 km²93.6% of basin
- 48.6 km²6.3% of basin
103 communes (GADM L5)Available for FRA, RWA
- Percy37.79 km²100% commune
- Hambye29.29 km²100% commune
- Cérences26.30 km²99% commune
- Notre-Dame-de-Cenilly25.52 km²100% commune
- Gavray20.26 km²100% commune
- Montpinchon17.50 km²100% commune
- Saint-Denis-le-Gast17.35 km²100% commune
- Quettreville-sur-Sienne15.97 km²97% commune
- Saint-Sever-Calvados15.68 km²55% commune
- Beslon15.58 km²87% commune
- La Lande-d'Airou14.68 km²100% commune
- Saint-Denis-le-Vêtu14.40 km²100% commune
- La Colombe14.35 km²100% commune
- Ver14.02 km²100% commune
- Soulles12.77 km²87% commune
- Orval12.66 km²100% commune
- Fleury12.59 km²100% commune
- Coutances12.49 km²100% commune
- Lengronne12.42 km²100% commune
- Roncey12.17 km²100% commune
- Trelly11.85 km²100% commune
- Cerisy-la-Salle11.85 km²70% commune
- Courcy11.44 km²100% commune
- Le Chefresne11.33 km²100% commune
- Le Mesnil-Villeman11.31 km²100% commune
- Sainte-Cécile11.13 km²98% commune
- Ouville11.12 km²100% commune
- Courson11.00 km²62% commune
- Le Mesnil-Garnier10.48 km²100% commune
- La Bloutière9.69 km²100% commune
- Saussey9.64 km²100% commune
- Le Gast9.62 km²76% commune
- Champrepus9.43 km²100% commune
- Contrières8.65 km²100% commune
- Savigny8.45 km²83% commune
- Villedieu-les-Poêles8.14 km²100% commune
- Saint-Aubin-des-Bois8.00 km²100% commune
- Bourguenolles7.71 km²99% commune
- Montabot7.54 km²67% commune
- Le Tanu7.27 km²69% commune
- Rouffigny7.08 km²100% commune
- Montaigu-les-Bois7.07 km²100% commune
- La Trinité7.07 km²77% commune
- La Meurdraquière6.98 km²92% commune
- Saint-Martin-de-Cenilly6.90 km²100% commune
- Guéhébert6.53 km²100% commune
- Le Mesnil-Amand6.44 km²100% commune
- Montchaton6.41 km²95% commune
- Heugueville-sur-Sienne6.36 km²100% commune
- Bricqueville-la-Blouette6.31 km²100% commune
- Hudimesnil6.10 km²33% commune
- Cambernon6.00 km²34% commune
- Belval5.91 km²100% commune
- Sourdeval-les-Bois5.75 km²100% commune
- Maupertuis5.72 km²100% commune
- Le Mesnil-Aubert5.65 km²100% commune
- Nicorps5.48 km²100% commune
- Le Guislain5.35 km²100% commune
- Dangy5.34 km²54% commune
- Chérencé-le-Héron5.23 km²55% commune
- Saint-Maur-des-Bois5.15 km²100% commune
- Équilly4.73 km²85% commune
- Le Mesnil-Rogues4.71 km²100% commune
- Coulouvray-Boisbenâtre4.35 km²24% commune
- Villebaudon4.32 km²79% commune
- La Baleine4.10 km²100% commune
- Beauchamps4.07 km²100% commune
- Saint-Pierre-de-Coutances4.00 km²100% commune
- Margueray3.80 km²89% commune
- Boisyvon3.76 km²99% commune
- Regnéville-sur-Mer3.28 km²32% commune
- La Haye-Bellefond3.19 km²100% commune
- Tourville-sur-Sienne3.17 km²39% commune
- Hyenville3.10 km²100% commune
- Chanteloup3.06 km²70% commune
- Montmartin-sur-Mer2.98 km²29% commune
- Fontenermont2.76 km²100% commune
- Folligny2.63 km²21% commune
- Grimesnil2.47 km²100% commune
- Moyon2.43 km²10% commune
- Gratot2.10 km²19% commune
- Hérenguerville1.95 km²61% commune
- La Haye-Pesnel1.83 km²28% commune
- Muneville-sur-Mer1.83 km²25% commune
- Sainte-Pience1.80 km²22% commune
- Le Loreur1.77 km²57% commune
- La Chapelle-Cécelin1.70 km²33% commune
- Sept-Frères1.49 km²16% commune
- Monthuchon1.44 km²19% commune
- Gouvets1.27 km²11% commune
- Cametours0.96 km²13% commune
- Camprond0.64 km²11% commune
- Saint-Martin-de-Bonfossé0.56 km²4% commune
- Beaucoudray0.29 km²6% commune
- Bricqueville-sur-Mer0.26 km²2% commune
- Montbray0.17 km²1% commune
- Saint-Martin-le-Bouillant0.10 km²1% commune
- Saint-Sauveur-la-Pommeraye0.08 km²1% commune
- Bréhal0.03 km²0% commune
- Saint-Jean-du-Corail-des-Bois0.02 km²1% commune
- La Chaise-Baudouin0.02 km²0% commune
- Champ-du-Boult0.01 km²0% commune
- La Vendelée0.00 km²0% commune
9 intersecting protected areas
La Sienne Et Ses Affluents
IUCN IVBiotope Protection Order
18.33 km² overlap
Bassin de l'Airou
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
8.53 km² overlap
Havre de la Sienne
IUCN Not ReportedSpecial Protection Area (Birds Directive)
2.19 km² overlap
Littoral Ouest du Cotentin de Bréhal à Pirou
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
2.18 km² overlap
Pointe d\'agon
IUCN IVLand acquired by Conservatoire du Littoral (national seaside and lakeside conservancy)
0.21 km² overlap
La Vire et ses affluents
IUCN IVBiotope Protection Order
0.01 km² overlap
Havre de regneville
IUCN IVLand acquired by Conservatoire du Littoral (national seaside and lakeside conservancy)
0.01 km² overlap
bricqueville la blouette
IUCN IVLand acquired by a regional conservatory of natural areas
0.01 km² overlap
fosse ardiere
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
4 377 distinct species · 144 204 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 de la Sienne : 15 espèces reliées par 193 interactions GloBI sur 6 types (connectance 11.7%, filtre Serrano α=0.2). 43 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°
10,9°C
Annual rain
798mm
Moisture idx (CMI)
0,10
Runoff
744mm/an
PET
718mm
AET
549mm
Mean slope
2,8°
Water table
177cm
Forest
1%
Crops
16%
Urban
1%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)