HydroBASINS lev08 watershed · #7080388550
Bassin de Lewis 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 4 administrative regions : Clark, Cowlitz, Multnomah, Skamania
Sub-basin area
2 713km²
Upstream area
2 713km²
Discharge
130,1m³/s
Mean elev.
686m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
4 dept-equivalent regions (GADM L2)
- 1641.6 km²60.4% of basin
- Clark800.1 km²29.4% of basin
- 278.0 km²10.2% of basin
- 0.1 km²0.0% of basin
13 intersecting protected areas
Mount St. Helens
IUCN VNational Volcanic Monument
136.61 km² overlap
Mount St. Helens
IUCN VGeothermal Area
43.28 km² overlap
Mount Adams
IUCN IbWilderness
35.87 km² overlap
Indian Heaven
IUCN IbWilderness
27.68 km² overlap
Steamboat Mountain
IUCN IaResearch Natural Area
3.51 km² overlap
Cedar Flats
IUCN IaResearch Natural Area
2.85 km² overlap
Wildlife Area Complex
2.09 km² overlap
Reserve Program
1.06 km² overlap
Columbia Land Trust
IUCN VLocal Land Trust
0.70 km² overlap
4 more protected areassorted by overlap area
Sister Rocks
IUCN IaResearch Natural Area
0.55 km² overlap
La Center Bottoms
IUCN VLocal Conservation Area
0.37 km² overlap
Trapper Creek
IUCN IbWilderness
0.08 km² overlap
Cedar
IUCN VTrails Park
0.01 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 182 distinct species · 175 930 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 Lewis River : 25 espèces reliées par 92 interactions GloBI sur 4 types (connectance 12.4%, filtre Serrano α=0.2). 14 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°
7,9°C
Annual rain
2 335mm
Moisture idx (CMI)
0,62
Runoff
1 490mm/an
PET
840mm
AET
661mm
Mean slope
12,4°
Water table
442cm
Forest
90%
Crops
2%
Urban
0%
Protected
8%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)