Hydrology

SNPI "NP" Belovezhskaya "Pushcha" occupies the eastern shelf of the basin of the river Visla, which is formed by the tributaries of the Bug - Narev and Pravaya Lesnaya. The rivers Svisloch and Ross (tributaries of the Neman) originate near the northern border of the park, and at the north-eastern border there are fountains of Yaselda (a tributary of the Pripyat). Here lies a water-parting between the basins of the Baltic and the Black Sea.

The territory of the national park is drained by the watersheds of Narev and Lesnaya (Levaya and Pravaya), which belong to the Visla basin.

Narev, which originates in the swamps of the Dykoe plot of land, plays an exceptionally important part in regulating the hydrological regime in the northern part of the national park. Its main tributary is the river Narevka. The main waterways in the southern part of the park are the rivers Pravaya Lesnaya and Levaya Lesnaya.

The chart shows the hydrographic network of the territory of the national park, and the table shows the characteristics of its main rivers and reservoirs.

Name	Length/area (km/ha)	Altitude of source above sea level	Average slope of the riverbed	Current speed (m/s)	Watershed (sq.km)
the river Belaya	13	157	o,6	0,2	366
the river Vishnya	17	158	0,8	0,1-0,2	121
the river Gvozna	9	159	0,6	0,1	-
the river Gorbach	9	167	1,1	0,3	-
the river Dryunovka	13	169	0,9	0,1-0,2	-
the river Kolonna	14	179	1,0	0,2-0,3	278
the river Lesnaya Levaya	38	162	0,4	0,2	-
the river Lesnaya Pravaya	29	-	0,5	0,3	-
the river Lomovka	10	186	2,6	0,1-0,2	-
the river Medyanka	17	189	1,2	0,1	91
the river Narev	33	159	0,6	0,2-0,3
the river Narevka	8	155	0,4	0,2-0,3	253
the river Nemerzhanka	9	160	0,9	0,3-0,4	32
the river Perevoloka	13	155	0,5	0,2-0,3	127
the river Plyuskovka	6	162	1,0	0,1	-
the river Polichna	8	159	1,1	0,2	-
the river Pchelka	13	169	1,4	0,1-0,2	55
the river Ross	4	174	1,4	0,1-0,2
the river Rudavka	14	156	0,8	0,2-0,3	173
the river Sipurka	11	170	1,5	0,3	-
the river Tochnitsa	6	158	0,4	0,1	-
the river Tushemlyanka	12	162	1,0	0,1	40
the river Horovka	6	176	2,2	0,2-0,3
Lyatskoe reservoir	260,4	-	-	-	-
Hmelevskoe reservoir	81,4	-	-	-	-
Sipurka reservoir	26,6	-	-	-	-
Pererovnitsa reservoir	20,1	-	-	-	-
Kolonna reservoir	16,9	-	-	-	-

In addition to those listed in the table, on the territory of the national park there are smaller streams and rivers, with a length of 5 km (Olkhovka, Vjunovka, Kulevka, Pererovnitsa, Kalinovets, Muravka, Tisovka, Pobojka, Pesyat, etc.).

There are no natural lakes there. But as a result of drainage and irrigation works several large artificial reservoirs (Lyadsky, Hmelevskoe, Sipurka, Pererovnitsa, Kolonna) and a number of smaller ones (12 with an area of 1 to 10 ha and 49 with an area of up to 1 ha) were created.

The network of reclamation canals is quite extensive. This is especially true in regard to the land transferred to the national park in the last decade, where in the 50-60s of the last century drainage works were carried out on the lands of collective farms bordering with the Belovezhskaya Pushcha. The riverbeds of some rivers (Narevka, Belaya) were straightened and deepened, which caused a retrogression of their level; new artificial waterways were created; Dokudovo (130 ha), Zubritsa (160 ha), Galevo Boloto (300 ha), Teplukhi (300 ha), Nikor (1450 hectares) plots of land were drained. The total area of ​​drained land in the Pushcha is 2340 hectares, and the total length of the irrigation and drainage network is 592 km according to the 2006 forest inventory.

The regime of the national park reservoirs is characterized by intensive spring floods and a stable summer-autumn and winter low water level. The rising of the water level during the spring flood usually begins in the middle of March (in early springs - in the second half of February, in late springs  - in the first decade of April) and lasts 7-15 days. The maximum spring rise of water is about 2.0-2.5 m (in some years 3.0 m). The average duration of flooding is about 60-70 days.

Summer low-water season occurs in the first half of May. Almost every year (1-2 times per season) it is interrupted by rainfall floods. The long-term amplitude of winter low-water levels is 20-40 cm.

A stable ice cover is formed in the third decade of December (the deviations from this period are possible:  from the first of December to the third decade of January). The usual thickness of ice is 35-45 cm. The reservoirs become open in the middle of March - the first decade of April. Rainfall floods are observed annually, in rainy years up to 3-4 times.

Stream runoff depends mainly on the amount of precipitation and evaporation. Most of it falls on the spring period.