HydroBASINS lev08 watershed · #2080056330
Bassin de Havelse Å
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 39 administrative regions : Albertslund, Allerød, Ballerup, Brøndby, Dragør +34
Sub-basin area
4 044,6km²
Upstream area
4 044,6km²
Discharge
1,76m³/s
Mean elev.
21m
Administrative coverage
39 dept-equivalent regions (GADM L2)
- 396.9 km²9.8% of basin
- 359.2 km²8.8% of basin
- 326.4 km²8.0% of basin
- 280.3 km²6.9% of basin
- 252.4 km²6.2% of basin
- 241.2 km²5.9% of basin
- 239.4 km²5.9% of basin
- 213.2 km²5.2% of basin
31 moreFull L2 list
- Roskilde212.6 km² · 5.2%
- Egedal126.0 km² · 3.1%
- Halsnæs123.3 km² · 3.0%
- Helsingør122.2 km² · 3.0%
- Fredensborg111.7 km² · 2.7%
- København89.5 km² · 2.2%
- Høje Taastrup77.7 km² · 1.9%
- Rudersdal73.2 km² · 1.8%
- Allerød68.0 km² · 1.7%
- Tårnby66.9 km² · 1.6%
- Greve61.1 km² · 1.5%
- Furesø56.5 km² · 1.4%
- Solrød40.3 km² · 1.0%
- Lyngby-Taarbæk38.9 km² · 1.0%
- Ballerup34.1 km² · 0.8%
- Hørsholm31.4 km² · 0.8%
- Ishøj26.1 km² · 0.6%
- Gentofte25.8 km² · 0.6%
- Gladsaxe25.0 km² · 0.6%
- Albertslund23.2 km² · 0.6%
- Hvidovre23.1 km² · 0.6%
- Brøndby21.4 km² · 0.5%
- Dragør19.0 km² · 0.5%
- Ringsted17.9 km² · 0.4%
- Glostrup13.4 km² · 0.3%
- Rødovre12.1 km² · 0.3%
- Herlev12.1 km² · 0.3%
- Vallensbæk9.0 km² · 0.2%
- Frederiksberg8.7 km² · 0.2%
- Faxe7.0 km² · 0.2%
- Stevns1.8 km² · 0.0%
30 intersecting protected areas
The bay of Sejerø and Saltbæk Vig
IUCN Not ReportedBaltic Sea Protected Area (HELCOM)
76.66 km² overlap
Sejrø Bugt, Nekselø Bugt and Saltbæk Vig
IUCN Not ReportedWetland of International Importance (Ramsar Site)
72.96 km² overlap
Sejerø Bugt og Saltbæk Vig
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
72.67 km² overlap
Roskilde Fjord og Jaegerspris Nordskov
IUCN Not ReportedBaltic Sea Protected Area (HELCOM)
72.47 km² overlap
Gribskov
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
68.38 km² overlap
Roskilde Fjord
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
62.13 km² overlap
Gribskov
IUCN Not ReportedSpecial Protection Area (Birds Directive)
60.44 km² overlap
Roskilde Fjord, Kattinge Vig og Kattinge Sø
IUCN Not ReportedSpecial Protection Area (Birds Directive)
55.76 km² overlap
Arresø, Ellemose og Lille Lyngby Mose
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
50.29 km² overlap
21 more protected areassorted by overlap area
Arresø
IUCN Not ReportedSpecial Protection Area (Birds Directive)
46.18 km² overlap
Øvre Mølleådal, Furesø og Frederiksdal Skov
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
38.43 km² overlap
Saltbæk Vig
IUCN Not ReportedSpecial Protection Area (Birds Directive)
36.44 km² overlap
Kalundborg Kommune private
IUCN Not Assigned§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
35.92 km² overlap
Sejerø Bugt og Nekselø
IUCN Not ReportedSpecial Protection Area (Birds Directive)
35.11 km² overlap
Vestamager and the sea west of
IUCN Not ReportedBaltic Sea Protected Area (HELCOM)
30.22 km² overlap
Vestamager og havet syd for
IUCN Not ReportedSpecial Protection Area (Birds Directive)
30.16 km² overlap
Vestamager og havet syd for
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
30.16 km² overlap
Saltbæk Vig
IUCN VProtected by conservation order, excl. Church surroundings
28.25 km² overlap
Gribskov Kommune public
IUCN IV§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
25.61 km² overlap
Holbæk Kommune private
IUCN Not Assigned§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
25.61 km² overlap
Protected by conservation order, excl. Church surroundings
25.48 km² overlap
W
IUCN IVMarine Strategy Area
25.47 km² overlap
Saltholm og omliggende hav
IUCN Not ReportedSpecial Protection Area (Birds Directive)
25.00 km² overlap
Saltholm og omliggende hav
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
25.00 km² overlap
Waters around Saltholm
IUCN Not ReportedBaltic Sea Protected Area (HELCOM)
24.99 km² overlap
Hillerød Kommune public
IUCN IV§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
23.21 km² overlap
Protected by conservation order, excl. Church surroundings
22.97 km² overlap
Halsnæs Kommune public
IUCN IV§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
22.56 km² overlap
Gurre Sø
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
21.97 km² overlap
Amager vildtreservat og fredni
IUCN Not AssignedProtected by conservation order, excl. Church surroundings
21.92 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
23 804 distinct species · 11 764 492 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 27 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 Havelse Å : 20 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 75 interactions GloBI sur 5 types (connectance 19.8%, filtre Serrano α=0.2). 8 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°
8,2°C
Annual rain
607mm
Moisture idx (CMI)
0,12
Runoff
367mm/an
PET
537mm
AET
434mm
Mean slope
1,0°
Water table
76cm
Forest
11%
Crops
49%
Urban
22%
Protected
15%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)