Nyabarongo River
The Nyabarongo (or Nyawarungu) is a major river in Rwanda, part of the upper headwaters of the Nile. With a total length of , it is the longest river entirely in Rwanda. It is extended in Lake Rweru including a upper course of Kagera River befor ...
. It rises in the western highlands of Rwanda and Burundi, flows east and then north along the border between those countries before joining the Nyabarongo River. The lower stretches contain important but unprotected wetlands, which are under threat from human activity.
Course
The Mugere River, a major headwater, rises at an elevation of in Burundi.
The river has sources at about elevation in the south of Rwanda.
Many of the valleys of the higher tributaries are choked by papyrus, which contains seasonal swamp forests.
The upstream portion of the river has a catchment area of about .
The lower course of the river is a belt of permanent wetlands about wide that ends where it reaches the Nyabarongo River. In this stretch the river drops from an elevation of to .
The swamp belt is fed from the right by lakes Cyohoha North and Cyohoha South.
The Burundi side of the swamp belt has about of permanent swamp along a stretch of the river, with the swamp reaching up the valleys of tributaries.
Climate
The upstream part of the river basin has average annual rainfall of about .
Average annual rainfall in the wetlands is about .
The climate of Rwanda is determined by the Intertropical Convergence Zone, which creates two rainy seasons.
One lasts from mid-September to mid-December and the other from March to May.
Climate change may be increasing the severity of both floods and droughts.
In the 1997-98 El Nino episode a large number of agricultural plantations in the shallows and swamps of the Nyabarongo and Akanyaru river basins were destroyed.
Flora
Beside the open channels the main plants are
Pistia stratiotes
''Pistia'' is a genus of aquatic plants in the arum family, Araceae. It is the sole genus in the tribe ''Pistieae'' which reflects its systematic isolation within the family. The single species it comprises, ''Pistia stratiotes'', is often calle ...
(water cabbage),
Leersia hexandra
''Leersia hexandra'' is a species of grass known by the common names southern cutgrass, clubhead cutgrass, and swamp rice grass.
(southern cutgrass) and
Oryza barthii
''Oryza barthii'', also called Barth's rice, wild rice, or African wild rice, is a grass in the rice genus ''Oryza''. It is an annual, erect to semierect grass. It has leaves with a short ligule (<), and Typha australis, Miscanthidium violaceum,
Cladium jamaicense
''Cladium mariscus'' is a species of flowering plant in the sedge family known by the common names swamp sawgrass, great fen-sedge, saw-sedge or sawtooth sedge. Previously it was known as elk sedge. It is native of temperate Europe and Asia wher ...
with some
papyrus
Papyrus ( ) is a material similar to thick paper that was used in ancient times as a writing surface. It was made from the pith of the papyrus plant, '' Cyperus papyrus'', a wetland sedge. ''Papyrus'' (plural: ''papyri'') can also refer to a ...
Bridelia micrantha
''Bridelia micrantha'', the mitzeeri or the coastal golden-leaf, is a tree in the family Phyllanthaceae and is native to tropical and southern Africa as well as to the island of Réunion in the Indian Ocean.
Description
A medium to tall tree ( ...
,
Ficus verruculosa
''Ficus verruculosa'', the water fig, is a species of fig from sub-saharan Africa.
It is found from north eastern South Africa, northern Botswana and Namibia to Uganda and west to Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjí ...
,
Myrica kandtiana
''Myrica'' is a genus of about 35–50 species of small trees and shrubs in the family Myricaceae, order Fagales. The genus has a wide distribution, including Africa, Asia, Europe, North America and South America, and missing only from Aus ...
and
Phoenix reclinata
''Phoenix reclinata'' (''reclinata'' - Latin, reclining), the wild date palm, Arabian date palm or Senegal date palm, is a species of flowering plant in the palm family native to tropical Africa, the Levant, the Arabian Peninsula, Madagascar an ...
Albizia gummifera
''Albizia gummifera'' is a species of legume in the family Fabaceae, native to sub-saharan Africa and Madagascar, and naturalized in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the large ...
.
Fauna
The marshland is an area of great biodiversity, particularly of birdlife.
There are records of at least 54 bird species with wetland habitats in the swamp region.
These include migrant
Malagasy pond heron
The Malagasy pond heron (''Ardeola idae''), also known as the Madagascar pond heron or Madagascar squacco heron, is a species of heron of the family Ardeidae. They breed in Madagascar, Réunion and the Seychells, and spend the non-breeding se ...
,
pallid harrier
The pale or pallid harrier (''Circus macrourus'') is a migratory bird of prey of the harrier subfamily. The scientific name is derived from the Ancient Greek. ''Circus'' is from ''kirkos'', referring to a bird of prey named for its circling fli ...
Lesser kestrel
The lesser kestrel (''Falco naumanni'') is a small falcon. This species breeds from the Mediterranean across Afghanistan and Central Asia, to China and Mongolia. It is a summer migrant, wintering in Africa and Pakistan and sometimes even to Indi ...
have been seen.
The near-threatened
papyrus gonolek
The papyrus gonolek (''Laniarius mufumbiri'') is a species of bird in the family Malaconotidae. It is found in Burundi, Democratic Republic of the Congo, Kenya, Rwanda, Tanzania, and Uganda.
It has specialised habitat requirements, being restr ...
sitatunga
The sitatunga or marshbuck (''Tragelaphus spekii'') is a swamp-dwelling antelope found throughout central Africa, centering on the Democratic Republic of the Congo, the Republic of the Congo, Cameroon, parts of Southern Sudan, Equatorial Guinea ...
, an antelope, is found in the swamps.
Human activities
The valley is not protected, and much of the land that is only flooded seasonally is cultivated at other times of the year.
The local people also engage in fishing in the river and swamps.
The wetlands are increasingly being used for agriculture.
In the dry season the local people cut and burn the marsh vegetation, steadily destroying the habitat.
In October 2005 Charles Karangwa, the
Butare
Butare (), also known as Huye, is a city (population: 50,220 as of 2012) in the Southern Province of Rwanda and the capital of Huye district. It is the fourth largest town in Rwanda by population.
History
The Belgian colonial rulers establish ...
Director for Economic Affairs,
said the people should increase their use of the Akanyaru wetland for crops, particularly maize.
In February 2011 the Minister of Lands and Environment told the people of the Gisagara District to make better use of the Akanyaru swamp, with more modern farming methods.
According to Minister Kamanzi the
Nile Basin Initiative The Nile Basin Initiative (NBI) is a partnership among the Nile riparian states that “seeks to develop the river in a cooperative manner, share substantial socioeconomic benefits, and promote regional peace and security”. The NBI began with a di ...
Cooperative Framework did not debar use. He said, "There is no agreement that prevents our population from using the water...of course in a good way."
In December 2012 the ministries of Infrastructure and Natural Resources were discussing how best to evaluate the quantity and quality of Akanyaru peat. Two companies, one from India and the other from Turkey, were to take over peat production.
A 100MW peat-fired power plant was to be built by the Turkish developer Hakan Mining and Generation Industry and Trade.