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Location Poland, wielkopolskie
Central coordinates 16o 44.00' East  51o 59.00' North
IBA criteria C3, C4, C6
Area 2,738 ha
Altitude 100 m
Year of IBA assessment 2010

Ogólnopolskie Towarzystwo Ochrony Ptaków

Site description A storage reservoir (777 ha) on the Samica river, connected by the Wonieœæ channel to the Obra river. The reservoir comprises five former lakes (Drzeczkowskie, Witos³awskie, Wojnowskie, Jezierzyckie, Wonieœæ), connected by a narrow channel (c.13 km long, 200-1,300 m wide), with meadows between them. A dam and sluice divide the upper part of the reservoir, where aquatic vegetation is well-developed, from the lower, where such vegetation is very localized. Adjacent there are fish-ponds, forests, meadows and cultivated fields. The reservoir stores water for agriculture and fire-fighting.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Bean Goose Anser fabalis passage  2004-2008  7,000-8,000 individuals  good  C3  Least Concern 
Ixobrychus minutus breeding  2004-2009  23-34 breeding pairs  good  C6  Not Recognised 
A4iii Species group - waterbirds passage  2004-2008  18,000-22,000 individuals  good  C4   

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
OChK Pojezierze Krzywinsko - Osieckie w woj. Wielkopolskim Protected Landscape Area 51,065 protected area contains site 900  
Zachodnie Pojezierze Krzywinskie - PLH300014 Habitats Directive 5,495 protected area overlaps with site 953  
Zbiornik Woniesc - PLB300005 Birds Directive 2,802 protected area overlaps with site 2,517  


IUCN habitat Habitat detail Extent (% of site)
Forest Alluvial and very wet forest; Broadleaved deciduous woodland; Mixed woodland; Native coniferous woodland  18%
Grassland Mesophile grasslands  24%
Wetlands (inland) Standing freshwater; Water fringe vegetation  21%
Artificial - terrestrial Arable land; Highly improved re-seeded landscapes; Ruderal land  35%
Other   2%

Land use

Land-use Extent (% of site)
agriculture 10%
fisheries/aquaculture 75%
forestry 5%
tourism/recreation 15%
water management 40%
hunting -

Protection status National High International None900 ha of IBA covered by Protected Landscape Area (Krzywiñsko-Osiecki, 71,425 ha).

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Woniesc reservoir. Downloaded from on 31/10/2014

To provide new information to update this factsheet or to correct any errors, please email BirdLife