The Kamchiya (also Kamchia and Kamčija, Bulgarian: Камчия) is a 191-kilometre (119 mi) river in eastern Bulgaria.
From its longest source, Golyama Kamchiya (Big Kamchiya), it has a total length of 245 km (152 mi).
The river Kamchiya proper starts from the confluence of the two rivers springing from Eastern Stara Planina, Golyama Kamchiya (itself formed by the confluence of the rivers Ticha and Vrana) and Luda Kamchiya (considered major source), flows eastward to the Black Sea and empties into it 25 km south of Varna, in the Resort of Kamchiya.
Running down through Eastern Stara Planina, the Kamchiya meanders through the Longoz or alluvial longose grove, and through the Kamchia (biosphere reserve), a UNESCO-listed biosphere reserve protecting the primeval forest from intensive logging and drainage that had decimated it by mid-20th century. The river mouth forms a sand barrier and often overflows its banks in the valley. The old synclines of the river leave swampy areas called azmatsi. The reserve is 40 km long (stretching throughout the longose grove to the river mouth) and up to 5 km wide.
The area around the river mouth is remarkable for its (frequently flooded) old growth forests of a riverine type, up to 450 meter-wide beaches with up to 19 meter-high banks, forested or grass-covered sand dunes, freshwater marshes, and marshy remnants of old riverbeds, cutting deep into the forest. The unusual coexistence of ash, oak, elm, alder and maple trees, sometimes rising up to 40–50 m with lianas climbing among the branches, creates the impression of a tropical forest, a real tangle of woods. The summer snowflake (Leucojum aestivum) and several buttercup species (Scilla sp.), as well as ferns, grow in the river delta. One can see otter, deer, wild boar and wild cats among the 26 mammal species. There are ospreys, eagles, and up to 200 other bird species, including 56 protected ones, and 25 fish species, among other wildlife.
The towns the river flows past include Veliki Preslav and Smyadovo in Shumen Province, and Dalgopol and Dolni Chiflik in Varna Province. The Ticha feeds the dam lake Ticha and Luda Kamchiya feeds the dam lakes Kamchiya and Tsonevo, which supply water to Varna and Burgas. Lake Tsonevo is also a preferred fishing spot for much of Eastern Bulgaria. The Luda Kamchiya gorge, which cuts across Stara Planina provides the easternmost of the three railway routes between northern and southern Bulgaria. The river valley is fertile, lined with orchards and vegetable gardens; much of it is irrigated. The lower Kamchiya is navigable for smaller motor boats.
