Location
Dolina Liwca (23 646,0 ha) is a birds' habitat. It is situated in mazowiecki voivodeship south-eastern from Wyszkow. The Liwiec river is 126 km long and it flows through Nizina Poludniowopodlaska and Srodkowomazowiecka lowlands. It is also the left tributary of Bug river. The area of the river basin is 2779 square km; average water float near the river estuary is - 11 cubic m per sec. Main tributaries are Muchawka, Kostrzyn and Osownica rivers.

Landscape
The area is covered with flooded meadows and pastures created on drained swamps. Some parts of the river preserved a natural character, while along others the river has been canalized; secondary swamps occur locally. In some places river banks are flat, overgrown by meadows and flooded wet pastures, along other fragments the banks are high. Meadows and pastures predominate in the valley, alder and alder-ash carrs and small woodlands with pine domination occur locally.

The width of the Liwiec river varies from 5 to 25 m. Water varieties are quite big and they can sometimes amount even 3 m. Dolina Liwiec is shorter and shallower than Bug river. The water of Liwiec river is not included in any category, but last years have shown that they are slowly purifying and in next few years they should achieve second clean category.

Climat
The climate of the area is temperate with big influence of continental climate which is known for quite warm and dry summers and quite frosty winters. In last few years we can observe intensification of sea climate influence which causes less difference between temperatures of summer and winter and that our seasons are getting warmer every year.

Ecosystem
The most valuable for birds fragments of the valley were drained in 1992 and 1993. The area includes two fish-pond complexes (48 ha and 70 ha) and the third one in Mordy town.
The area is covered by following form of habitats:

• coniferous forests - 6% of the area
• broad leaved forests - 6% of the area
• mixed forests - 2% of the area
• meadows and shrubs communities - 50% of the area
• agricultural habitats - 33% of the area
• water bodies (standing and flowing) - 1% of the area
• other areas - 2% of the area

Fauna
There are 19 species of protected birds in the Dolina Liwca listed in Annex I of Birds' Directive.

• Great Bittern
• Black Stork
• White Stork
• Marsh Harrier
• Lesser Spotted Eagle
• Spotted Crake
• Little Crake
• Corn Crake
• Common Crane
• Common Tern
• Black Tern
• Common Kingfisher
• Black Woodpecker
• Middle Spotted Woodpecker
• Woodlark
• Tawny Pipit
• Bluethroat
• Barred Warbler
• Ortolan Bunting

The site was classified as the Special Protection Area, because of the ideal habitat conditions for them. You can also admire species of fish here which are listed in Annex II of Birds' Directive: Asp fish, Weatherfish, Spined Loach, Golden Spined Loach.

Flora
Among protected plants listed in Annex II of Birds' Directive we can found here: Anielica Palustris and Chinese Agrimony (Agrimonia pilosa)

Protection and Threats
Main threat to the area is drainage that causes land's drying.
The area is covered by following forms of nature conservation: Protected Landscape Area: Siedlecko-Wegrowski (35840,0 ha)