HydroBASINS lev08 watershed · #7080357840
Bassin de Chehalis 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 5 administrative regions : Grays Harbor, Lewis, Mason, Pacific, Thurston
Sub-basin area
1 613,3km²
Upstream area
3 758,2km²
Discharge
137,89m³/s
Mean elev.
146m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de Skookumchuck River477 km²
- Bassin de Salzer Creek97 km²
5 dept-equivalent regions (GADM L2)
- 699.1 km²43.2% of basin
- Thurston606.0 km²37.5% of basin
- Lewis224.3 km²13.9% of basin
- Mason85.6 km²5.3% of basin
- 2.7 km²0.2% of basin
17 intersecting protected areas
Wildlife Area Complex
13.08 km² overlap
Billy Frank Jr. Nisqually
IUCN IVNational Wildlife Refuge
10.05 km² overlap
Marine Protected Area
6.32 km² overlap
Reserve Program
5.29 km² overlap
Mima Mounds
IUCN VNatural Area Preserve
2.58 km² overlap
Reserve Program
2.35 km² overlap
Reserve Program
1.27 km² overlap
Black River
IUCN VPrivate Conservation Land
1.25 km² overlap
Unknown
IUCN VPark
1.03 km² overlap
8 more protected areassorted by overlap area
Black River Ranch 2011
IUCN VEnvironmental System
0.85 km² overlap
Reserve Program
0.58 km² overlap
Forestry Riparian Easement Program 280
IUCN Not AssignedEasement
0.15 km² overlap
PCON90
IUCN VPrivate Conservation
0.10 km² overlap
Reserve Program
0.09 km² overlap
Boots Satterlee
IUCN VPrivate Conservation Land
0.08 km² overlap
Capitol Land Trust
IUCN VLocal Land Trust
0.07 km² overlap
PCON11
IUCN VPrivate Conservation
0.07 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 238 distinct species · 304 287 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 36 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 Chehalis River : 25 espèces reliées par 74 interactions GloBI sur 4 types (connectance 11.1%, filtre Serrano α=0.2). 12 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°
10,0°C
Annual rain
1 646mm
Moisture idx (CMI)
0,43
Runoff
1 377mm/an
PET
912mm
AET
649mm
Mean slope
6,6°
Water table
214cm
Forest
81%
Crops
8%
Urban
2%
Protected
1%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)