HydroBASINS lev08 watershed · #7080762450
Bassin de San Marcos River
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 : Caldwell, Gonzales, Guadalupe
Sub-basin area
273,8km²
Upstream area
2 237,1km²
Discharge
15,54m³/s
Mean elev.
140m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de York Creek375 km²
- Bassin de San Marcos River216 km²
3 dept-equivalent regions (GADM L2)
- Guadalupe161.4 km²59.0% of basin
- Caldwell87.8 km²32.1% of basin
- 24.3 km²8.9% of basin
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 281 distinct species · 24 270 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 33 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 San Marcos River : 26 espèces reliées par 69 interactions GloBI sur 3 types (connectance 12.3%, filtre Serrano α=0.2). 8 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°
20,1°C
Annual rain
863mm
Moisture idx (CMI)
-0,44
Runoff
243mm/an
PET
1 539mm
AET
730mm
Mean slope
0,9°
Water table
86cm
Forest
1%
Crops
43%
Urban
1%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)