HydroBASINS lev08 watershed · #8080001930
Bassin de Twentymile 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 : Anchorage, Kenai Peninsula, Valdez-Cordova
Sub-basin area
2 381,8km²
Upstream area
2 381,8km²
Discharge
9,59m³/s
Mean elev.
585m
Administrative coverage
3 dept-equivalent regions (GADM L2)
- 1890.4 km²78.9% of basin
- 431.4 km²18.0% of basin
- 14.9 km²0.6% of basin
11 intersecting protected areas
Heritage Area
955.44 km² overlap
Chugach
IUCN VState Park
655.31 km² overlap
Anchorage Coastal
IUCN VWildlife Refuge
8.64 km² overlap
Nellie Juan-College Fiord
IUCN IbWilderness Study Area
2.58 km² overlap
Potter Marsh
IUCN VState Conservation Area
2.11 km² overlap
Business Park
IUCN VWetlands
0.12 km² overlap
Helen Louise Mcdowell
IUCN VSanctuary
0.06 km² overlap
Prc Resolution 2005-01_1
IUCN VLocal Conservation Area
0.00 km² overlap
Prc Resolution 2005-01_2
IUCN VLocal Conservation Area
0.00 km² overlap
2 more protected areassorted by overlap area
82-338 Openspace
IUCN VLocal Conservation Area
0.00 km² overlap
75-80 Openspace
IUCN VLocal Conservation Area
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 880 distinct species · 895 115 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 29 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 Twentymile River : 18 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 66 interactions GloBI sur 3 types (connectance 15.2%, 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°
0,2°C
Annual rain
791mm
Moisture idx (CMI)
0,37
Runoff
1 818mm/an
PET
455mm
AET
374mm
Mean slope
18,9°
Water table
677cm
Forest
7%
Crops
0%
Urban
7%
Protected
73%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)