Notwane River | |
River | |
View of Gaborone Dam in the Notwane River
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Country | Botswana |
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Source | Kalahari |
Mouth | Pala Camp |
- location | Limpopo River, South Africa/Botswana border |
- elevation | 847 m (2,779 ft) |
- coordinates | 23°44′56″S 26°57′37″E / 23.74889°S 26.96028°ECoordinates: 23°44′56″S 26°57′37″E / 23.74889°S 26.96028°E |
Basin | 18,053 km2 (6,970 sq mi) |
The Notwane River (or Ngotwane River) is a river in southeastern Botswana. Certain sections of its course form the international boundary with South Africa. Its mouth is at the head of the Limpopo River. It has a catchment area of 18,053 square kilometers.
The Notwane rises about 11 kilometres (6.8 mi) south of Ramotswa, and runs along the border in a northeast direction to enter the Limpopo at the same longitude as Mahalapye. The Notwane has its source in the sandveld, at the eastern fringes of the Kalahari Desert. It flows roughly northeastwards past the most densely populated area of Botswana, passing east of Lobatse and close to Gaborone. Finally it joins the left bank of the Limpopo River at the border with South Africa, just 6 km short of the confluence of the Limpopo with the Matlabas River.
The Notwane basin is drained by the Notwane itself and its tributaries the Taung, Metsemaswaane and Nywane. Its main tributaries are the Taung, Peleng and Nywane rivers. All the rivers in the Notwane basin are ephemeral experiencing mostly brief, seasonal flow depending from the rainfall. The Notwane and Taung riverbeds are dry during the dry season and in years of drought they may be completely dry the whole year round. All these rivers may cause flash floods.
The banks of the Notwane River have been occupied since the middle Stone Age. The first modern settlement was Moshaweng, which was established by Chief Gaborone of the Tlokwa in the late 1880s, near the site of the modern capital. The city of Gaborone, an expansion of the earlier settlement, was developed on the Notwane River in the 1960s in part due to proximity to the railway, in part due to availability of water provided by the river.
The Gaborone Dam, which supplies water to the city of Gaborone, has a capacity of 144,000,000 cubic metres (5.1×109 cu ft). Further upstream, the Ngotwane Dam in Lehurutshe, South Africa has a capacity of 18,000,000 cubic metres (640,000,000 cu ft). In the Gaborone dam catchment area there are many other dams, mostly very small, with only the Nnywane Dam near Lobatse being used for domestic water supply. Following a 1992 study on their impact on downstream water resources, a moratorium was placed on construction of small dams in the catchment area.