Location
The refuge is situated in Western-Pomeranian voivodship, in Police county. It lies in Rownina Wkrzanska mesoregion, between Stolec, Rzedziny, Legi, Wegornik, Zalesie, Podbierze, Poddymin, Dobieszczyn and Polish-German border.

Ecosystem
Central part of the refuge is the Swidwie lake together with the river Gunica flowing through the lake. The lake is an 890-ha natural reservoir with fertile waters (an eutrophic lake). Over 2/3 of the lake is occupied by reed fields which border with alder swamps and meadows. On the open water we can observe vegetation characteristic for eutrophic waters - petty free floating plants and floating species rooted to the bottom: yellow water-lily, white water-lily, yellow floating heart as well as rare water plants: European frog-bit and water soldier.

Over a half of the refuge's area (north-eastern and southern parts) is covered by fragments of Puszcza Wkrzanska (the Wkra Primeval Forest). These are mainly pine woods, with well preserved parts of beech forests and alder swamps in boggy depressions.

South-western part of the refuge has different character. Fields, meadows and pastures, which in the past used to serve as arable lands, are cut by numerous drainage ditches. Currently most of the area is not agriculturally exploited, and is overgrown by shrubs and trees. The landscape is varied by little inner-field lobes of forest. Apart from the Swidwie lake the refuge also encompasses a fragment of the border Stolsko lake, many little inner-field reservoirs (mainly peat excavation pits) as well as peatlands and a small fish pond.

At least 42 species specified in 1 Appendix of the Birds Directive have been recorded within the area of "Jezioro Swidwie" refuge. Presence and number of migrating population of Taiga bean goose, greater white-fronted goose and hatching population of little crake and black tern allow to qualify this place to Natura 2000 site.

"Jezioro Swidwie" refuge is one of 10 most important Polish refuges of black tern and little tern (over 4% of hatching population of this species), as well as nesting place for rare in Poland little gull. Many species of water-swamp birds find here perfect conditions for hatching. During hatching season the area is populated by at least 1% of Polish population of such species as: red-necked grebe, ruff, osprey, greylag goose, common moorhen, little gull, water rail; in relatively high density occur: bittern, hen harrier, mute swan, garganey, gadwall, northern shoveler, white-winged tern.

Swidwie is also very important place for migrating birds. Apart from the geese mentioned above during migrations the following species rest here: great egret, whistling swan, wood sandpiper, smew. Woods of Puszcza Wkrzanska are hatching habitat of black stork, honeybuzzard, red and black kite, lesser spotted eagle, great spotted woodpecker and white-backed woodpecker. In the refuge numerous is hatching marsh harrier, corn crake, common kingfisher, wood lark, bluethroat, barred warbler, red-breasted flycatcher, red-backed shrike and ortolan bunting. Also appears no-hatching osprey, peregrine falcon and merlin.

Threats
At present the biggest threat to the area is connected with insufficient control over hunting, fish and mammals pouching. In addition dynamic development of recreation pose potential threat to natural qualities. It is important to monitor renewed, though still slow, development of agriculture and observe changes which can take place in the environment due to such development.

Lumbering old-growth forests and hollow trees, removing dead wood from a forest, planting tree monocultures in Puszcza may lead to reduction of population of forest birds. Potential threat can come from development of border traffic and execution of plans to build new border crossing in Dobieszczyn.

Forms of Protection of Nature
Because of its special natural values the lake has been taken under protection as a nature reserve: Swidwie. Since 1978 it has also been included to wetlands specified in the Ramsar Convention. There are projects to broaden the area of the reserve and create a complex of protected areas Swidwie-Gottesheide.