HydroBASINS lev08 watershed · #7080520980
Bassin de Grand 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 6 administrative regions : Adair, Clarke, Decatur, Madison, Ringgold +1
Sub-basin area
1 192,7km²
Upstream area
1 192,7km²
Discharge
8,4m³/s
Mean elev.
363m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
6 dept-equivalent regions (GADM L2)
- UnionIowa · United States596.3 km²49.9% of basin
- AdairIowa · United States305.4 km²25.6% of basin
- DecaturIowa · United States97.7 km²8.2% of basin
- MadisonIowa · United States78.2 km²6.6% of basin
- ClarkeIowa · United States67.6 km²5.7% of basin
- RinggoldIowa · United States49.0 km²4.1% of basin
14 intersecting protected areas
Sand Creek
IUCN VWildlife Management Area
13.74 km² overlap
Three Mile Lake
IUCN VWildlife Management Area
10.83 km² overlap
Twelve Mile Lake (Union)
IUCN VWildlife Management Area
6.01 km² overlap
Reserve Program
1.79 km² overlap
Talmage Hill
IUCN VWildlife Area
0.85 km² overlap
Reserve Program
0.74 km² overlap
Reserve Program
0.58 km² overlap
Groesbeck County
IUCN VWildlife Area
0.44 km² overlap
Watershed Protection
0.36 km² overlap
5 more protected areassorted by overlap area
Reserve Program
0.07 km² overlap
Agricultural Conservation Easement Program - Wetland Reserve Easements (ACEP-WRE), Decatur, IA
IUCN VConservation Easement
0.03 km² overlap
Lorimor
IUCN VWildlife Area
0.02 km² overlap
Farm Service Agency Interest Of Ia
IUCN Not AssignedConservation Easement
0.02 km² overlap
Mount Pisgah Cemetery
IUCN VState Preserve
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
612 distinct species · 8 217 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 Grand River : 29 espèces reliées par 73 interactions GloBI sur 4 types (connectance 11.6%, filtre Serrano α=0.2). 7 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°
9,7°C
Annual rain
874mm
Moisture idx (CMI)
-0,17
Runoff
223mm/an
PET
1 047mm
AET
741mm
Mean slope
2,0°
Water table
126cm
Forest
3%
Crops
65%
Urban
0%
Protected
3%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)