LAKE VICTORIA BASIN

The KatongaWetland System, Uganda

The Katonga Basin covers the districts of Kabarole, Kyenjojo, Mbarara, Mubende, Sembaule and Mpigi and enters Lake Victoria through Nakinga Bay, Masaka district. The major wetlands within the Katonga catchment area are the Katonga, Nabajuzi, Kyojja and the shores of Lake Victoria. Parts of Masaka, Mubende Mbarara and Sembabule are generally flat with a few flat-crested hills with long, steep flanking slopes fluted by valleys and short pediments. The valleys are wide and some have rivers flowing through them. The wetlands are on the floodplains, along rivers and Lake margins (Lake Victoria Basin Commission 2007). The Katonga wetlands are mainly supplied by water from surface flow from rivers, precipitation and groundwater. The wetlands are characterized by low rainfall as it is part of the Masaka-Ankole Dry Corridor. The main activity in this area is livestock (cattle) farming. Dominant plants in the Katonga wetlands include freshwater reed species ( Cyperus papyrus , Loudetia and Miscanthus ), seasonally flooded herbaceous wetlands where species composition is variable, seasonally flooded wooded grassland, freshwater floating leaved but rooted vegetation, and freshwater rooted macrophytes. Other dominant plant species in the Katonga wetland system are papyrus ( Cyperus papyrus ), Loudetia and Miscanthus species. These plants are tolerant to soils that are acidic and deficient in plant nutrients. The flood plains dominate the western catchment and are comprised mainly of wooded grasslands with acacia trees, which in certain instances form dense bushes. The grasslands are dominated by Imperata (spear grass), Sporobolus and Hyparrhenia species.

Sitatunga and otters are common animal species in the Katonga wetlands. Wetland fish, in particular catfish and lungfish, are also common. Common birds include cranes, ducks and ibis. Papyrus is typically used for common local crafts (for example, baskets, trays and mats). Masaka district lies in the coffee and banana farming area and these crops need mulching to conserve water and soil. Miscanthus species are commonly used to mulch banana plantations. The wetlands are a major source of food, mainly fish and game meat. They also provide water for domestic use and for watering livestock. Wetlands play a role in controlling floods, moderating the local climate and trapping sediment. The wetlands along rivers stabilize the riverbanks and lakeshores. Masaka Municipality receives its water supply from the Nabajuzi wetland and sewerage effluent is purified through the same system. Only 12 km² of the wetland area in Masaka district has been converted – mainly for crop production. Little wetland conversion has taken place in the Katonga wetlands system because of the low fertility and acidic conditions of the soil. Most of the wetlands and their surroundings come under the mailo land tenure system – a customary form of freehold practised in some parts of Uganda. The extensive and heavily waterlogged wetlands are public land, which includes the Nabajuzi, Kyogya and Katonga wetlands. A few wetlands in the Katonga system are partially or fully protected as part of the Forest Reserves; these include the Kanywa, Lwamunda and Namirembe wetlands.

Papyrus plants

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