HydroBASINS lev08 watershed · #5080116420
Bassin de San Juan 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 12 administrative regions : Alaminos, Bay, Cabuyao, Calamba City, Laguna lake +7
Sub-basin area
437,4km²
Upstream area
437,4km²
Discharge
18,15m³/s
Mean elev.
136m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
12 dept-equivalent regions (GADM L2)
- Laguna lake128.3 km²29.4% of basin
- 108.4 km²24.9% of basin
- 87.6 km²20.1% of basin
- 50.5 km²11.6% of basin
- 20.0 km²4.6% of basin
- 16.9 km²3.9% of basin
- 11.9 km²2.7% of basin
- 11.3 km²2.6% of basin
4 moreFull L2 list
- Tagaytay City0.5 km² · 0.1%
- Talisay0.4 km² · 0.1%
- Alaminos0.1 km² · 0.0%
- Bay0.0 km² · 0.0%
3 intersecting protected areas
Mount Makiling Forest Reserve
IUCN Not AssignedForest Reserve
23.94 km² overlap
Mount Makiling Forest Reserve
IUCN Not AssignedASEAN Heritage Park
23.94 km² overlap
Protected Landscape
3.37 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 053 distinct species · 16 483 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 39 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 Juan River : 34 espèces reliées par 35 interactions GloBI sur 3 types (connectance 4.5%, filtre Serrano α=0.2). 6 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°
26,5°C
Annual rain
2 045mm
Moisture idx (CMI)
0,25
Runoff
1 464mm/an
PET
1 522mm
AET
1 223mm
Mean slope
2,4°
Water table
71cm
Forest
2%
Crops
30%
Urban
54%
Protected
6%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)