The Sió or Sió-csatorna (''Sió-Channel'') is a fully regulated river in midwest

Hungary Hungary is a landlocked country in Central Europe. Spanning much of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and ...

. It is the outlet, at the eastern end, of

Lake Balaton Lake Balaton () is a freshwater rift lake in the Transdanubian region of Hungary. It is the List of largest lakes of Europe, largest lake in Central Europe, and one of the region's foremost tourist destinations. The Zala River provides the larges ...

, flowing out of the lake in

Siófok Siófok (; ; ) is a town in Somogy County, Hungary on the southern bank of Lake Balaton. It is the Somogy County#Municipalities, second largest municipality in Somogy County and the seat of Siófok District. It covers an area of about between Lak ...

. The long Sió flows into the river

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 ...

near the city of

Szekszárd Szekszárd (, formerly also ''Szegzárd''; ; or ; ) is a small city in southern Hungary and the capital of Tolna County. By population, Szekszárd is the smallest county capital in Hungary; by area, it is the second-smallest (after Tatabánya). ...

. The Sió flows through the Hungarian counties Somogy, Fejér and Tolna, its main tributaries are Kapos from the right and Sárvíz from the left. The

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

of the Sió (including Balaton) covers more than a third of the

Transdanubia Transdanubia ( ; , or ', ) is a traditional region of Hungary. It is also referred to as Hungarian Pannonia, or Pannonian Hungary. Administrative divisions Traditional interpretation The borders of Transdanubia are the Danube River (north and ...

region. The Sió's basin size is and its average discharge at the

mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

is .

References

Rivers of Hungary {{Hungary-river-stub