The Leśna Prawa or Pravaja Liasnaja () is a river in north-eastern
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...
and western
Belarus
Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an a ...
. At its
confluence
In geography, a confluence (also ''conflux'') occurs where two or more watercourses join to form a single channel (geography), channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main ...
tributary
A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...
of the
Bug River
The Bug or Western Bug is a major river in Central Europe that flows through Belarus (border), Poland, and Ukraine, with a total length of .Brest.
The Leśna Prawa flows through the geographical region of Europe known as the ''Wysoczyzny Podlasko – Bialoruskie'' (English: Podlasie and Belarus Plateau) located within the
Podlaskie Voivodeship
Podlaskie Voivodeship ( ) is a Voivodeships of Poland, voivodeship in northeastern Poland. The name of the voivodeship refers to the historical region of Podlachia (in Polish, ''Podlasie''), and significant part of its territory corresponds to th ...
of
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...
Belarus
Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an a ...
The Leśna Prawa rises in the Polish part of the Białowieża Forest and flows eastwards for roughly 33 km in Poland before continuing for about 30 km in Belarus. Within Belarus, the river forms a sinuous kayaking route that begins at Kamyanyuki and passes through Paszuki and Czernaki, then receives its left tributary near . It continues past , Kamieniec and Małe Muriny, then on to Siulki, Baranki, Młyny, Pokry and Czarnawczyce, before reaching and discharging into the
Bug River
The Bug or Western Bug is a major river in Central Europe that flows through Belarus (border), Poland, and Ukraine, with a total length of .Brest. The channel alternates between muddy stretches and shallow, stony fords, with widths of 0.5–6 m and depths of 0.5–1.5 m throughout most of its course.
Along its course the river passes through extensive
floodplain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...
woods that host a rich assemblage of birdlife, including Eurasian sparrowhawk (''
Accipiter nisus
The Eurasian sparrowhawk (''Accipiter nisus''), also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barred ...
Acrocephalus palustris
The marsh warbler (''Acrocephalus palustris'') is an Old World warbler currently classified in the family Acrocephalidae. It breeds in temperate Europe and the western Palearctic and winters mainly in southeast Africa. It is notable for incorpora ...
'') and large winter congregations of
geese
A goose (: geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (grey geese and white geese) and ''Branta'' (black geese). Some members of the Tadorninae subfamily (e.g., Egyp ...
,
duck
Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...
s and
mute swan
The mute swan (''Cygnus olor'') is a species of swan and a member of the waterfowl family Anatidae. It is native to much of Eurasia, and (as a rare winter visitor) the far north of Africa. It is an introduced species in North America, home to ...
s. Cultural landmarks line the banks, among them a wooden Orthodox church of St Alexander Nevsky at Szyszowo, the 19th-century manor complex at Nowickowicze, pl, the 1913 Romanov commemorative tower at Kamieniec and several historic roadside chapels and mills.
Water quality and ecosystem services
The Leśna Prawa River flows for roughly 33 km in Poland and a further 30 km in Belarus as a right-bank
tributary
A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...
of the
Bug River
The Bug or Western Bug is a major river in Central Europe that flows through Belarus (border), Poland, and Ukraine, with a total length of .wastewater
Wastewater (or waste water) is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of do ...
and agricultural runoff. These factors inhibit mixing and have led to persistently low water quality.
Analyses of water samples from six sites in 2012 showed elevated concentrations of
biogenic
A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, it has developed to encompass any constituents, secretions, and metabolites of p ...
compounds—
ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...
nitrogen,
nitrate
Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...
nitrogen and total
phosphorus
Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...
—and depleted levels of
dissolved oxygen
Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It can ...
physicochemical
Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mecha ...
parameters fall below the threshold for good ecological status, preventing the river from serving as a source of drinking water abstraction or supporting healthy fish populations. Moreover, unpleasant odour and reduced clarity have diminished its aesthetic and recreational appeal, despite the presence of regional cycling and walking routes and a
narrow-gauge railway
A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge (distance between the rails) narrower than . Most narrow-gauge railways are between and .
Since narrow-gauge railways are usually built with tighter cur ...