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Ghana Rivers and Lakes
Ghana is drained by a large number of streams and rivers. In
addition, there are a number of coastal lagoons, the huge man-made
Lake Volta, and Lake Bosumtwi, southeast of Kumasi and which has no
outlet to the sea. In the wetter south and southwest areas of
Ghana, the river and stream pattern is denser, but in the area
north of the Kwahu Plateau, the pattern is much more open, making
access to water more difficult. Several streams and rivers also dry
up or experience reduced flow during the dry seasons of the year,
while flooding during the rainy seasons is common.
The major drainage divide runs from the southwest part of the
Akwapim-Togo Ranges northwest through the Kwahu Plateau and then
irregularly westward to the Côte d'Ivoire border. Almost all the
rivers and streams north of this divide form part of the Volta
system. Extending about 1,600 kilometers in length and draining an
area of about 388,000 square kilometers, of which about 158,000
square kilometers lie within Ghana, the Volta and its tributaries,
such as the Afram River and the Oti River, drain more than twothirds of the country. To the south of the divide are several
smaller, independent rivers. The most important of these are the
Pra River, the Tano River, the Ankobra River, the Birim River, and
the Densu River. With the exception of smaller streams that dry up
in the dry seasons or rivers that empty into inland lakes, all the
major rivers in the country flow into the Gulf of Guinea directly
or as tributaries to other major rivers. The Ankobra and Tano are
navigable for considerable distances in their lower reaches.
Navigation on the Volta River has changed significantly since
1964. Construction of the dam at Akosombo, about eighty kilometers
upstream from the coast, created vast Lake Volta and the associated
768,000-kilowatt hydroelectric project. Arms of the lake extended
into the lower-lying areas, forcing the relocation of 78,000 people
to newly created townships on the lake's higher banks. The Black
Volta River and the White Volta River flow separately into the
lake. Before their confluence was submerged, the rivers came
together in the middle of the country to form the main Volta River.
The Oti River and the Daka River, the principal tributaries of the
Volta in the eastern part of the country, and the Pru River, the
Sene River, and the Afram River, major tributaries to the north of
the Kawhu Plateau, also empty into flooded extensions of the lake
in their river valleys. Lake Volta is a rich source of fish, and
its potential as a source for irrigation is reflected in
agricultural mechanization agreement signed in the late 1980s to
irrigate the Afram Plains. The lake is navigable from Akosombo
through Yeji in the middle of the country; a twenty-four-meter
pontoon was commissioned in 1989 to link the Afram Plains to the
west of the lake with the lower Volta region to the east.
Hydroelectricity generated from Akosombo supplies Ghana, Togo, and
Benin.
On the other side of the Kwahu Plateau from Lake Volta are
several river systems, including the Pra, Ankobra, Tano and Densu.
The Pra is the easternmost and the largest of the three principal
rivers that drain the area south of the Volta divide. Rising south
of the Kwahu Plateau and flowing southward, the Pra enters the Gulf
of Guinea east of Takoradi. In the early part of the twentieth
century, the Pra was used extensively to float timber to the coast
for export. This trade is now carried by road and rail
transportation.
The Ankobra, which flows to the west of the Pra, has a
relatively small drainage basin. It rises in the hilly region of
Bibiani and flows in a southerly direction to enter the gulf just
west of Axim. Small craft can navigate approximately eighty
kilometers inland from its mouth. At one time, the Ankobra helped
transport machinery to the gold-mining areas in the vicinity of
Tarkwa. The Tano, which is the westernmost of the three rivers,
rises near Techiman in the center of the country. It also flows in
a southerly direction, but it empties into a lagoon in the
southeast corner of Côte d'Ivoire. Navigation by steam launch is
possible on the southern sector of the Tano for about seventy
kilometers.
A number of rivers are found to the east of the Pra. The two
most important are the Densu and Ayensu, which are important as
sources of water for Accra and Winneba, respectively. The country
has one large natural lake, Lake Bosumtwi, located about thirty-two
kilometers southeast of Kumasi. It occupies the steep-sided caldera
of a former volcano and has an area of about forty-seven square
kilometers. A number of small streams flow into Lake Bosumtwi, but
there is no drainage from it. Apart from providing an opportunity
for fishing for local inhabitants, the lake serves as a tourist
attraction.
Data as of November 1994
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