| ORANGE RIVER | ||||||
| Overview | Geophysical | Hydrology & Geohydrology | Ecology | Tributaries | Climate | |
| Populated places | Land-uses | Water treatment plants | Sanitation & waste water treatment | Dams | ||
|
|
Map of the Orange River | |||||
|
|
The Orange River is South Africa's major river. Its length from the Drakensberg in Lesotho to the mouth at the West Coast at Alexander Bay is approximately 2 300 km. Where it rises in the eastern highlands of Lesotho, the river is known as the Senqu River. The Orange River forms the borders between several South African provinces as well as the border between Namibia (southern boundary) and South Africa. The Orange River flows through the semi-desert/desert area along the southern border of Namibia. |
|
|||||
|
|
The estimated annual sediment load is approximately 120 million tons, 6 times more than any other river in South Africa. | ||||||
|
|
The Department of Water Affairs and Forestry divided the Orange River catchment in two water management areas, that is the the Upper Orange and the Lower Orange Water Management Areas. | ||||||
|
|
The Upper Orange area (upstream of Douglas in the Northern Cape) lies predominantly within the Free State, but also occupies portions of the Eastern and Northern Cape provinces. The Caledon River, which forms the border between South Africa and Lesotho over most of its length, is the largest tributary to the Orange River within the Upper Orange area. (Ref.1) |
||||||
|
|
||||||
|
|
The Lower Orange area (between Douglas and Alexander Bay) is the lowest Water Management Area in the Orange/Vaal River Basin (Catchments) and as such is affected by upstream activities in the Orange River and the Vaal River. The area is arid with rainfall varying from 400 mm in the east to 50 mm on the west coast. The topography of the area is flat with large pans or endoreic areas that do not contribute runoff to the Orange River system. The Orange River, which forms a green strip in an otherwise arid landscape, also forms the border between South Africa and Namibia over about 550 km to the west of 20 degrees longitude. The Vaal River, the main tributary to the Orange River, has its confluence with the Orange River about 13 km west of Douglas. Other tributaries are the Ongers and Hartebeest Rivers from the south, and the Molopo River and Fish River (Namibia) from the north. (Ref.2) |
||||||
|
|
 |
 |
||
| NOTE: If you have any photos (digital or prints) which you think eWISA can add to this page to help to complete this 'story book', do not hesitate to contact us at ewisa@wamsys.co.za . You will be fully referenced and the material will also be added to the eWISA photo library. Note: Past (historical) are as important as present photos. | |||||
|
|
References: |
|
Ref.1. Department of Water Affairs and
Forestry, South Africa. 2004. Internal Strategic Perspective: Upper
Orange Water Management Area. Prepared by PDNA, WRP Consulting
Engineers (Pty) Ltd, WMB and Kwezi-V3 on behalf of the Directorate:
National Water Resource Planning. DWAF Report No P WMA.
Ref.2. Department of Water Affairs and Forestry, South Africa. 2004. Internal Strategic Perspective: Lower Orange Water Management Area. Prepared by PDNA, WRP Consulting Engineers (Pty) Ltd, WMB and Kwezi-V3 on behalf of the Directorate: National Water Resource Planning. DWAF Report No P WMA 14/000/00/0304 |
| Useful links | |
