The Koita River is a river in Eastern Finland

Eastern Finland

Eastern Finland was a province of Finland from 1997 to 2010. It bordered the provinces of Oulu, Western Finland and Southern Finland. It also bordered Russia.- History :...

 and partly in Russia in Northern Europe. Having its origin just by the international boundary in Ilomantsi

Ilomantsi

Ilomantsi is municipality and a village of Finland.It is located in the province of Eastern Finland and is part of the North Karelia region. The municipality has a population of and covers an area of of which is water. The population density is...

 of Northern Karelia in Finland, the Koita River enters the territory of the Republic of Karelia

Republic of Karelia

The Republic of Karelia is a federal subject of Russia .-Geography:The republic is located in the northwestern part of Russia, taking intervening position between the basins of White and Baltic seas...

 in Russia, to return in Finland some 30 kilometres further south. It then flows northwest through the Petkeljärvi National Park

Petkeljärvi National Park

Petkeljärvi National Park is a national park in Ilomantsi in the North Karelia region of Finland. It was established in 1956 and covers . Its specialities are e.g. fortification from the Continuation War, some of which have been renovated, and valuable eskers...

 and the Kesonsuo bog area, and further downstream receives the outflow from Lake Koitere. The main part of the waters are then directed through an underground tunnel of the 84-megawatt Pamilo hydroelectric power plant

Pamilo hydroelectric power plant

The Pamilo hydroelectric power plant is a power station in Eno, Finland that supplies electricity to Finland. It was opened in 1955.It is notable for being Vattenfall's largest hydroelectric power plant in Finland, with an installed generating capacity of 84 megawatts across three units and...

., which bypasses some 20 kilometres of the natural course of the lowest part of the river.

Koitajoki is a tributary of Pielisjoki

Pielisjoki

Pielisjoki River is a 67 km long river in Eastern Finland. It is the sixth most fast-flowing river in Finland and the largest river draining into Lake Saimaa. The river connects the two largest lakes in North Karelia, Pielinen and Pyhäselkä...

 that flows from the lake Pielinen

Pielinen

Pielinen is the fourth largest lake of Finland, with a drainage basin area of that is equally distributed between eastern Finland and Russia. The creation of the lake and its outlet is attributed to a post-glacial isostatic rebound, which resulted in uplift of the land...

 in to Lake Pyhäselkä

Lake Pyhäselkä

Pyhäselkä is a lake in Finland. It forms the northernmost part of the Saimaa lake system....

 in Northern Karelia, Finland. It is part of the Vuoksi River

Vuoksi River

The Vuoksi River runs in the northernmost part of the Karelian Isthmus from Lake Saimaa in southeastern Finland to Lake Ladoga in northwestern Russia. The river enters Lake Ladoga in three branches, an older main northern branch at Priozersk , a smaller branch few km...

 basin in Finland and Russia, which flows through Lake Ladoga

Lake Ladoga

Lake Ladoga is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, not far from Saint Petersburg. It is the largest lake in Europe, and the 14th largest lake by area in the world.-Geography:...

 in Russia and further through the Neva River

Neva River

The Neva is a river in northwestern Russia flowing from Lake Ladoga through the western part of Leningrad Oblast to the Neva Bay of the Gulf of Finland. Despite its modest length , it is the third largest river in Europe in terms of average discharge .The Neva is the only river flowing from Lake...

 into the Gulf of Finland

Gulf of Finland

The Gulf of Finland is the easternmost arm of the Baltic Sea. It extends between Finland and Estonia all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn...

.