The Orange River

The Orange River forms the southern border between Namibia and South Africa. Originating from the Drakensberg Mountains in Lesotho and flowing west to the Atlantic Ocean, the river drops 3 km in altitude and stretches 2160 km in its entirety. In Lesotho, the river is called Senqu. In South Africa, the river is the Gariep River and its tributary is the Vaal, and in Namibia it is the Oranje or Orange, named for William V of Orange and not the orange color of its waters.

The Orange River and the riparian zone (Nomad Africa Adventure Tours)

The Orange River enjoys the distinction of the longest river south of the Tropic of Capricorn. Bisecting the Namib Desert, the river also borders the south of the Kalahari arid region (not actually a desert). Over millions of years, the Orange River washed diamonds from the Kimberley region of South Africa into the ocean, where currents and wave action tossed them onto the dunes of the Namib. So Namibia has the river to thank for coastal diamond fields. Alluvial diamonds can also be found in the river and some commercial mines still operate near the mouth of the river and on the middle stretch.

Multiple dams and water projects on the Orange River allow the use of river water for agriculture, industry, mining, and hydroelectricity. Some of these include the Gariep Dam, the Vanderkloof Dam, and the Lesotho Highlands Project. Because most of the water storage infrastructure on the Orange River was built and operated by South Africa, there are ongoing negotiations between Namibia and South Africa about equitable allocation and use of water.

- Hayden

https://www.britannica.com/place/Orange-River

http://www.namibweb.com/orangeriver.htm

http://www.namibia-travel.net/travelguide/southern-namibia/orange-river.html

http://www.orangesenqurak.org/UserFiles/File/OtherV2/Equitable%20Water%20Allocation%20SA-NA%20Shilomboleni%202006.pdf