HydroBASINS lev08 watershed · #7080012670
Bassin de Arroyo Las Posas
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 : Los Angeles, Ventura
Sub-basin area
2 305,3km²
Upstream area
2 305,3km²
Discharge
0,04m³/s
Mean elev.
227m
Administrative coverage
2 dept-equivalent regions (GADM L2)
- 1162.3 km²50.4% of basin
- 1095.2 km²47.5% of basin
30 intersecting protected areas
Open Space
18.67 km² overlap
Westridge-Canyonback
IUCN VWilderness Park
6.36 km² overlap
Cold Creek Canyon
IUCN VPreserve
3.69 km² overlap
Cameron
IUCN VNature Preserve
2.84 km² overlap
Ballona Wetlands
IUCN VEcological Reserve
2.38 km² overlap
Charmlee
IUCN VWilderness Park
2.16 km² overlap
Marine Protected Area
1.92 km² overlap
Portuguese Bend
IUCN VNature Preserve
1.59 km² overlap
Hope
IUCN VNature Preserve
1.45 km² overlap
21 more protected areassorted by overlap area
Ormond
IUCN VBeach
1.34 km² overlap
Reserve
1.29 km² overlap
Marine Protected Area
1.22 km² overlap
Arroyo Conejo
IUCN VNature Preserve
1.02 km² overlap
Deane Dana Friendship
IUCN VNatural Area
0.91 km² overlap
Marine Protected Area
0.90 km² overlap
Marine Protected Area
0.86 km² overlap
Upper Filiorum
IUCN Not AssignedReserve
0.84 km² overlap
Forrestal
IUCN VNature Preserve
0.64 km² overlap
McCrea
IUCN VWildlife Preserve
0.52 km² overlap
Local Conservation Area
0.50 km² overlap
Open Space
0.47 km² overlap
Private Conservation
0.40 km² overlap
Three Sisters
IUCN VPreserve
0.40 km² overlap
White Point
IUCN VNature Preserve
0.38 km² overlap
Palos Verdes Shoreline
IUCN VShoreline
0.36 km² overlap
Middle Santa Clara River
IUCN VPrivate Conservation
0.34 km² overlap
La Sierra Canyon
IUCN VWetlands
0.34 km² overlap
Conservation
IUCN Not AssignedEasement
0.30 km² overlap
Vicente Bluffs
IUCN VReserve
0.28 km² overlap
Dal Molin-Runcie
IUCN VNature Preserve
0.24 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
11 365 distinct species · 5 344 174 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 45 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 Arroyo Las Posas : 38 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 66 interactions GloBI sur 2 types (connectance 6.7%, filtre Serrano α=0.2). 7 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°
16,4°C
Annual rain
425mm
Moisture idx (CMI)
-0,66
Runoff
179mm/an
PET
1 248mm
AET
363mm
Mean slope
6,7°
Water table
418cm
Forest
57%
Crops
10%
Urban
45%
Protected
13%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)