The Tundzha ( ; ; ''Tonsus'' in antiquity) is a river in southeastern
Bulgaria
Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...
and northwesternmost
Turkey
Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...
, a left tributary of the
Maritsa
Maritsa or Maritza ( ), also known as Evros ( ) and Meriç ( ), is a river that runs through the Balkans in Southeast Europe. With a length of , . With a length of 390 km, of which 350 km are in Bulgaria, it is Maritsa's longest tributary, though in terms of discharge it is second after the
Arda.
Tundzha Glacier on
Livingston Island
Livingston Island (Russian name ''Smolensk'', ) is an Antarctic island in the Southern Ocean, part of the South Shetland Islands, South Shetlands Archipelago, a group of List of Antarctic and subantarctic islands, Antarctic islands north of the ...
in the
South Shetland Islands
The South Shetland Islands are a group of List of Antarctic and subantarctic islands, Antarctic islands located in the Drake Passage with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the n ...
,
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
is named after Tundzha River.
Geography
Course

The Tundzha springs at an altitude of 2,083 m some 250 m south of the summit of Yurushka Gramada (2,136 m) in the central
Balkan Mountains
The Balkan mountain range is located in the eastern part of the Balkan peninsula in Southeast Europe, Southeastern Europe. It is conventionally taken to begin at the peak of Vrashka Chuka on the border between Bulgaria and Serbia. It then runs f ...
.
Its source lies about two kilometers east of
Botev Peak
Botev Peak ( ) is, at above sea level, the highest peak of the Balkan Mountains in southeastern Europe. It is located close to the geographic centre of Bulgaria, and is part of the Central Balkan National Park.
Until 1950, when it was renamed ...
(2,376 m), the highest summit in the mountain range. It flows south in a deep valley with steep slopes and a large longitudinal gradient. The riverbed is rocky with gravels. Its water current is high, reaching velocity of 1.5–2 m/s.
At the town of
Kalofer
Kalofer ( pronounced:) is a town in central Bulgaria, located on the banks of the Tundzha between the Balkan Mountains to the north and the Sredna Gora to the south. Kalofer is part of Plovdiv Province and the Karlovo municipality. It is best kno ...
the Tundzha turns east and then enters the western reaches of the
Kazanlak Valley, where the river valley widens to 3–4 km at the village of
Aleksandrovo and then narrows to one kilometer. In that section it flows closer to the northern slopes of
Sredna Gora
Sredna Gora ( ) is a mountain range in central Bulgaria, situated south of and parallel to the Balkan Mountains and extending from the river Iskar (river), Iskar to the west and the elbow of river Tundzha north of the city of Yambol to the east. ...
and has steep right slopes. The river meanders, the riverbed is 20–25 m wide and 0.7 m deep. The bottom consists of sand and fine gravel. The velocity of the current is 1–1.5 m/s; the gradient is 1.5‰.
The river valley narrows further between the villages of
Viden and
Buzovgrad, reaching several dozen meters at the village of
Koprinka, where the dam of the
Koprinka Reservoir has been constructed; it then again widens to one kilometer. The riverbed in that section is 28–30 m, the current is 1 m/s; the bottom consists of sand and gravel.
Downstream of
Buzovgrad the valley widens significantly, reaching 5–7 m; the river forms several strongly curved meanders, especially between the villages of
Yagoda and
Zimnitsa. The gradient in that section is 1.5‰. Just downstream of the town of
Nikolaevo the Tundzha enters the
Tvarditsa Valley and then the Mezhdenik Gorge, where the river valley narrows, at places to 60–100 m; in the narrowest section is the dam of the
Zhrebchevo Reservoir. It exits the gorge at the village of
Binkos and enters the
Sliven Valley for the next 70 km. There, the river valley reaches a width of 2–3 km, the gradient decreases to 1,0‰; the Tundzha forms numerous meanders. Further east, the river valley widens to more than 7 km.
Southeast of the village of
Zhelyu Voyvoda the river turns south and maintains that general direction to its mouth. Before the city of Yambol, the Tundzha passes through a short and wide gorge and receives its largest tributary, the
Mochuritsa. Downstream from the city the river enters the Yambol Field. The river valley in that section is vaguely pronounced, reaching a width of 10–40 km; that is the section with the most meanders in its entire course. At the village of
Konevets the river enters the elongated Elhovo Field, where the riverbed is 40–50 m wide and the average depth is 1–1.5 m; the gradient decreases to 0.7‰. Its banks are low, gently sloping and overgrown with willows. The bottom is sandy.
Downstream from the village of
Knyazhevo the Tundzha enters the long picturesque Srem Gorge between the
Sakar mountain range to the west and the
Dervent Heights to the east. The gorge is narrow, reaching some 100–200 m, with steep bare slopes and rocky uneven riverbed. There is a small widening of 0.8–1 km between the villages of
Srem and
Ustrem, after which the gorge narrows again with deforested slopes and in places almost canyon-like. In that section the river is about 60 m wide with an average depth of 1–2 m. Shortly after exiting the gorge the river forms the
Bulgaria–Turkey border for about 10 km. East of the village of
Matochina the Tundzha leaves Bulgaria and enters Turkey, where it flows into the Maritsa at an altitude of 32 m in the city of
Edirne
Edirne (; ), historically known as Orestias, Adrianople, is a city in Turkey, in the northwestern part of the Edirne Province, province of Edirne in Eastern Thrace. Situated from the Greek and from the Bulgarian borders, Edirne was the second c ...
.
Basin and hydrology

Its drainage basin covers an area of 8,429 km
2 or 15.9% of the Maritsa's total. Of them 7,884 km
2 are in Bulgaria,
encompassing territory of seven provinces — northern
Stara Zagora Province
Stara Zagora (), formerly known as the Stara Zagora okrug, is a province of south-central Bulgaria. It is named after its administrative and industrial centre—the city of Stara Zagora—the sixth-biggest town in the country. The provin ...
, central
Sliven Province, over 80% of
Yambol Province
Yambol (, ''oblast Yambol'', former name Okrug, Yambol okrug) is a province in southeastern Bulgaria, neighbouring Turkey to the south. It is named after its main city Yambol, while other towns include Straldzha, Bolyarovo and Elhovo. The provi ...
, eastern
Haskovo Province, northwesternmost
Burgas Province
Burgas (, formerly the Burgas okrug) is a province in southeastern Bulgaria on the southern Bulgarian Black Sea Coast. The province is named after its administrative and industrial centre, the city of Burgas, the fourth biggest town in the countr ...
, as well as small areas of
Plovdiv
Plovdiv (, ) is the List of cities and towns in Bulgaria, second-largest city in Bulgaria, 144 km (93 miles) southeast of the capital Sofia. It had a population of 490,983 and 675,000 in the greater metropolitan area. Plovdiv is a cultural hub ...
and
Gabrovo Provinces. The remaining 548 km
2 are in Turkey's
Edirne Province
Edirne Province () is a Turkish province located in East Thrace. Part of European Turkey, it is one of only three provinces located entirely within continental Europe. Its area is 6,145 km2, and its population is 414,714 (2022). Edirne Province ...
. About 33% of the catchment area is forested, or 2,613 km
2.
Beginning from the right bank of the Tundzha mouth the boundaries of its basin head northeast through the southern outreaches of the Sakar mountain range, enters Bulgaria, follows Sakar's main ridge to its highest point Vishegrad (856 m), turns north, runs through the ridge of the
Manastirski Heights, descends to the easternmost limits of the
Upper Thracian Plain and then ascends the ridge of the
Svetiiliyski Heights. Continuing north, the boundary again descend to the Upper Thracian Plain and north of the village of
Staro Selo reaches the main ridge of the Sredna Gora mountain range, where it turns west. South of Kalofer, the boundary heads north again and via Strazhata reaches the main ridge of the Balkan Mountains at the summit of Yurushka Gramada. In that section the river basin borders the drainage systems of the Kemal (in Turkey), Kalamitsa, Levchenska reka, Golyama reka,
Sazliyka,
Omurovska reka,
Brezovska reka and
Stryama
The Stryama ( , known in Antiquity as ''Syrmus'') is a river in southern Bulgaria, an important left tributary of the Maritsa. It originates in the Balkan Mountains. The river is 110 kilometres in length and is the sixth longest in the Marits ...
, all of them left tributaries of the Maritsa.
From Yurushka Gramada the boundary turns east, reaching the
Vratnik Pass, following the main Balkan watershed via the subdivisions of the Balkan Mountains Kalofer Mountain, Shipka Mountain, Tryavna Mountain and Elena–Tvarditsa Mountain. There, it limits the basins of the rivers
Osam and
Yantra
Yantra (; 'machine'/'contraption') is a geometrical diagram, mainly from the Tantric traditions of the Indian religions. Yantras are used for the worship of deities in temples or at home; as an aid in meditation; and for the benefits believe ...
, right tributaries of the
Danube
The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...
.
From Vratnik Pass begins the border with the drainage systems of the rivers flowing directly into the
Black Sea
The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...
— the
Luda Kamchiya,
Kamchiya,
Aytoska reka,
Rusokastrenska reka,
Sredetska reka and
Fakiyska reka. The boundary in that section continues east through the crests of the Sliven, Stidovska and Karnobat mountains, and then turns south. It reaches the
Hisar Heights, following their ridge westwards, then continues southwest through the
Bakadzhitsite Heights, turning southeast at their highest point Asanbair (515 m), runs through several isolated elevations and reaches the northwestern slopes of the
Strandzha mountain range, where it reaches the Bulgaria–Turkey border east of the village of
Strandzha. It then turns west–southwest, following the state border for 15 km along the crest of the
Dervent Heights until their highest point Gyurgenbair (555 m), there the basin boundary turns south–southwest, entering Turkey, runs east of the town of
Lalapaşa and reaches the left banks of the Tundzha river mouth. In that last section it borders the basins of the
Ergene
Ergene (; ; ''Eryinis'', , ''Agriánēs'') is a major left tributary of the Maritsa (Meriç) river, flowing entirely in the East Thrace region of Turkey.
The river rises from the southern part of Strandzha mountain, not far from the Black Sea and ...
and Sazlıdere, both left tributaries of the Maritsa.
The river receives over 60 tributaries. The most important include the
Mochuritsa (86 km, left),
Popovska reka (72 km, left),
Sinapovska reka (50 km, right) and
Tazha (26 km, left).
The annual distribution of Tundzha river discharge is determined by seasonal changes that characteristic of its basin's location in the transitional zone between the
temperate continental climatic zone and the
continental Mediterranean zone — generally high temperatures, short duration of snow cover in winter for the lowland areas and retention of relatively stable snow cover in winter in the mountainous parts of the basin, irregular distribution of rain with a peak in spring and a dry period with little rainfall in summer and autumn.
In the western part of the Balkan Mountains, at the town of Kalofer, high water occurs in March–April, when spring rains overlap with snowmelt of the snow cover at higher altitudes above 1500–1700 m; low water begins in July. In the lower part of the catchment area the high water period shifts to winter or autumn, while the low water period begins one or two months earlier, in May or June. The average annual discharge is 0.47 m
3/s at Kalofer, 33.5 m
3/s at Elhovo and 39.7 m
3/s at the Bulgaria–Turkey border. The average annual rainfall within the catchment basin is 550 mm; the average altitude of the basin 386 m; the density of the river network varies between 0.23 and 0.66 km/km
2.
Ecology
The ichtyofauna of the Tundzha shares similarities with that of the Maritsa basin in general. A 2014 study identified 19 fish species in its lower course on Bulgarian territory. Autochthonous taxa include
Vardar nase,
Macedonian vimba,
Orpheus dace,
round-scales barbel,
asp,
common carp
The common carp (''Cyprinus carpio''), also known as European carp, Eurasian carp, or simply carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Ark ...
,
Prussian carp,
crucian carp,
common roach,
common bleak,
spined loach
The spined loach (''Cobitis taenia'') is a common freshwater fish in Europe. It is sometimes known as spotted weather loach, not to be confused with the "typical" weather loaches of the genus '' Misgurnus''. This is the type species of the spiny ...
,
European bitterling, etc. The
Dnieper chub can be found in the river
Mochuritsa.
Most of the river course is included in the
European Union
The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
network of nature protection areas
Natura 2000
Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectiv ...
in four separate protected areas. Its uppermost course is situated within the
Dzhendema Reserve of the
Central Balkan National Park. Near the town of Elhovo along the Tundzha's lower course are located three nature reserves,
Gorna Topchia,
Dolna Topchia and
Balabana, which protect some of the most important riparian forests in the interior of Bulgaria, as well as rare flora and fauna, including major populations of
common pheasant
The common pheasant (''Phasianus colchicus''), ring-necked pheasant, or blue-headed pheasant, is a bird in the pheasant family (biology), family (Phasianidae). The genus name comes from Latin ''phasianus'' 'pheasant'. The species name ''colchic ...
.
Settlements and economy
There are 33 settlements along the Tundzha, including five towns and 25 villages in Bulgaria, and one town and four villages in Turkey. On Bulgarian territory are Kalofer (town) in Plovdiv Province,
Osetenovo, Aleksandrovo,
Pavel Banya (town), Viden,
Ovoshtnik, Yagoda,
Yulievo,
Shanovo, Zimnitsa,
Nova Mahala, Nikolaevo (town) and
Panicherevo in Stara Zagora Province, Banya,
Chervenakovo, Binkos,
Mechkarevo,
Samuilovo,
Krushare and Zhelyu Voyvoda in Sliven Province, Yambol (city),
Zavoy,
Veselinovo,
Okop,
Hanovo,
Tenevo, Konevets and
Elhovo
Elhovo ( ) is a Bulgarian town in Yambol Province, located on the left bank of the Tundzha river, between Strandzha and Sakar Mountain, Sakar mountains. Second largest city in the region after Jambol, the city is located at 36 km from border ...
(town) in Yambol Province, as well as Knyazhevo and Srem in Haskovo Province. In Turkey are located
Suakacağı,
Hatipköy,
Değirmenyanı,
Avarız and Edirne (city). In total, there are 252 settlements in the whole Tundzha river basin on Bulgarian territory.
There are 264 reservoirs in the Tundzha catchment area; the largest are
Zhrebchevo (400 million m
3) and
Koprinka (142.2 million m
3).
They are very important for the irrigation of large tracts of arable land and water discharge regulation. There are also several small-scale hydro power plants. The total annual waterflow is 1,265.8 million m
3, of which 245.1 million m
3 are utilized for irrigation, industrial and potable water supply and electricity generation and additional 56.1 million m
3 are diverted to the Maritsa and Yantra river systems for economic needs.
There are many industrial enterprises in the Tundzha Valley, especially in
Kazanlak
Kazanlak ( , known as Seuthopolis () in ancient times, is a List of cities and towns in Bulgaria, town in Stara Zagora Province, Bulgaria. It is located in the middle of the plain of the same name, at the foot of the Balkan Mountains, Balkan mo ...
, Sliven and Yambol, that require water supply, including the largest producer of military equipment in Bulgaria
Arsenal AD
JSC Arsenal AD () is a Bulgarian joint-stock company based in Kazanlak, engaged primarily in the manufacture of firearms and military equipment. It is Bulgaria's oldest arms supplier.
History
The company's history can be traced back to 1878 w ...
, based in Kazanlak.
Since ancient times the river valley has been an important transport corridor in direction west–east in its upper half and north–south further downstream.
Nowadays it is traversed by two major roads of the national network, a 116.2 km stretch of the first class
I-6 road Gyueshevo–
Sofia
Sofia is the Capital city, capital and List of cities and towns in Bulgaria, largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain, in the western part of the country. The city is built west of the Is ...
–Sliven–
Burgas
Burgas (, ), sometimes transliterated as Bourgas, is the second largest city on the Bulgarian Black Sea Coast in the region of Northern Thrace and the List of cities and towns in Bulgaria, fourth-largest city in Bulgaria after Sofia, Plovdiv, an ...
between Kalofer and Sliven, and a 36.6 km section of the first class
I-7 road Silistra
Silistra ( ; ; or ) is a town in Northeastern Bulgaria. The town lies on the southern bank of the lower Danube river, and is also the part of the Romanian border where it stops following the Danube. Silistra is the administrative center of the ...
–
Shumen
Shumen (, also Romanization of Bulgarian, romanized as ''Shoumen'' or ''Šumen'', ) is the List of cities and towns in Bulgaria, tenth-largest city in Bulgaria and the administrative and economic capital of Shumen Province.
Etymology
The city ...
–Yambol–
Lesovo, which continues as D535 to Edirne in Turkey.
A section of railway line No. 3 Iliyantsi (Sofia)–
Karlovo–Sliven–
Karnobat
Karnobat ( ) is a town in the Burgas Province, Southeastern Bulgaria. It is the administrative centre of the homonymous Karnobat Municipality. According to the 2021 census, the town had a population of 16,483.
Geography
Karnobat municipality i ...
–
Varna served by the
Bulgarian State Railways
The Bulgarian State Railways (, abbreviated as БДЖ, BDZ or BDŽ) are Bulgaria's state railway company and former largest railway carrier in the country, established as an entity in 1888. The company's headquarters are located in the capital So ...
crosses the river valley in direction west–east between Kalofer and Slivan. The Tundzha valley is also traversed by a small section of railway line No. 8
Plovdiv
Plovdiv (, ) is the List of cities and towns in Bulgaria, second-largest city in Bulgaria, 144 km (93 miles) southeast of the capital Sofia. It had a population of 490,983 and 675,000 in the greater metropolitan area. Plovdiv is a cultural hub ...
–
Stara Zagora
Stara Zagora (, ) is a city in Bulgaria, and the administrative capital of Stara Zagora Province. It is located in the Upper Thracian Plain, near the cities of Kazanlak, Plovdiv, and Sliven. Its population is 121,582 making it the sixth largest c ...
–Yambol–Karnobat–Burgas between Yambol and Zavoy, and the two lines merge at Zimnitsa a few kilometers east of the great river bend at Zavoy.
Gallery
File:DarKaya DSC04318.jpg , Darkaya locality, Bulgaria
File:Тунджа_24.jpg , Riparian vegetation in autumn, Bulgaria
File:Тунджа_10.jpg , Winter view near Elhovo
File:Saraçhane Bridge over Tunca river (Tundzha) 02.jpg, Tundzha River as seen from Saraçhane Bridge, built by Hadım Şehabeddin
Hadım Şehabeddin Pasha (Old Turkish: Şihābüddīn; 1436–53), also called Kula Şahin Pasha, was an Ottoman Empire, Ottoman general and governor that served Sultan Mehmed II (r. 1444–46; 1451–81). Brought to the Ottoman court at a young ...
Pasha in Edirne
Edirne (; ), historically known as Orestias, Adrianople, is a city in Turkey, in the northwestern part of the Edirne Province, province of Edirne in Eastern Thrace. Situated from the Greek and from the Bulgarian borders, Edirne was the second c ...
, Turkey.
File:Saraçhane Bridge over Tunca river (Tundzha) 03.jpg, Tundzha River as seen from Saraçhane Bridge, built by Hadım Şehabeddin
Hadım Şehabeddin Pasha (Old Turkish: Şihābüddīn; 1436–53), also called Kula Şahin Pasha, was an Ottoman Empire, Ottoman general and governor that served Sultan Mehmed II (r. 1444–46; 1451–81). Brought to the Ottoman court at a young ...
Pasha in Edirne
Edirne (; ), historically known as Orestias, Adrianople, is a city in Turkey, in the northwestern part of the Edirne Province, province of Edirne in Eastern Thrace. Situated from the Greek and from the Bulgarian borders, Edirne was the second c ...
, Turkey.
File:Saraçhane Bridge over Tunca river (Tundzha) 07.jpg, Tundzha River as seen from Saraçhane Bridge, built by Hadım Şehabeddin
Hadım Şehabeddin Pasha (Old Turkish: Şihābüddīn; 1436–53), also called Kula Şahin Pasha, was an Ottoman Empire, Ottoman general and governor that served Sultan Mehmed II (r. 1444–46; 1451–81). Brought to the Ottoman court at a young ...
Pasha in Edirne
Edirne (; ), historically known as Orestias, Adrianople, is a city in Turkey, in the northwestern part of the Edirne Province, province of Edirne in Eastern Thrace. Situated from the Greek and from the Bulgarian borders, Edirne was the second c ...
, Turkey.
Citations
Sources
*
*
*
{{Rivers of Turkey
Rivers of Bulgaria
Rivers of Turkey
International rivers of Europe
Landforms of Plovdiv Province
Landforms of Stara Zagora Province
Landforms of Sliven Province
Landforms of Yambol Province
Landforms of Haskovo Province
Landforms of Edirne Province