Desná is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in Moravia

Moravia

Moravia is a historical region in Central Europe in the east of the Czech Republic, and one of the former Czech lands, together with Bohemia and Silesia. It takes its name from the Morava River which rises in the northwest of the region...

, left tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Morava river. The word means "right hand" in the Old East Slavic language

Old East Slavic language

Old East Slavic or Old Ruthenian was a language used in 10th-15th centuries by East Slavs in the Kievan Rus' and states which evolved after the collapse of the Kievan Rus...

. Its length is 43.6 km (27 mi), and its drainage basin covers 326.3 km² (126 sq mi).The mean annual discharge at its mouth is 4.48 m³/s (12,713 ft³/s).

The Desna River originates in the Jeseník Mountains

Hrubý Jeseník

Hrubý Jeseník is a mountain range of Eastern Sudetes in northern Moravia and Czech Silesia. It is the second highest mountain range in the Czech Republic.Some of the most interesting sights:*Praděd, the highest mountain...

  of Olomoucký kraj, Czech republic

Czech Republic

The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

. The source is situated on the north slope of Kamzičník Mountain. The Desná then goes southwest through a deep valley toward the town of Šumperk

Šumperk

Šumperk is a town and district in the Olomouc Region of the Czech Republic. It is called "The Gate to Jeseníky mountains."- History :Šumperk was founded by German colonists in 1269. The German name Schönberg means "beautiful hill", and the name Šumperk is a Czech garbling of the original German...

.
After approximately 43,6 km, the Desná flows into the Morava river near Postřelmov

Postřelmov

Postřelmov is a village and municipality in Šumperk District in the Olomouc Region of the Czech Republic.The municipality covers an area of , and has a population of 3,276 ....

 village.

The Dlouhé stráně Hydro Power Plant

Dlouhé Stráne Hydro Power Plant

Dlouhé stráně Hydro Power Plant is a large pumped storage plant in the Czech Republic that has 2 turbines with a nominal power of 325 MW each having a total capacity of 650 MW. The power plant is built on the Desná river...

is built on the river.