Orange River

High in the mountains, small streams join to make the river.

Over a very long time, the water cut deep valleys into the rock.

The Orange begins in the highlands of Lesotho, where it is called the Senqu. FEOW explains that these mountains are made of basalt, rock from lava that poured out about 180 million years ago, lying on top of softer sandstone. Fast streams have cut gorges through the basalt and into the sandstone, and some valleys are more than 1,000 meters deep.

Far downstream, below Augrabies Falls, the river runs through a gorge about 240 meters deep and 18 kilometers long.

FEOW describes the Drakensberg-Maloti Highlands as heavily dissected by small streams, most of them headwaters of the Senqu/Orange. The peaks above 2,300 m are basalts extruded about 180 million years ago over horizontal sedimentary strata topped by soft sandstones; the rivers have eroded gorges through the basalts into the sandstones, and the cliffs and valleys can be in excess of 1,000 m deep. Streams drop up to 1,200 m in 60-70 km before slowing and widening in the lowlands.

Downstream in South Africa, South African Tourism describes the river cascading 56 m at Augrabies Falls into a gorge about 240 m deep that runs for about 18 km; the park's rock formations include Moon Rock, a weathered granite dome rising 30 m.

The river starts in cold, wet mountains. It ends in a hot, dry desert.

At the sea, sand sometimes blocks its way.

After the highlands, the Senqu flows southwest through the lowlands of Lesotho. In South Africa it is called the Orange, and it flows west through dry and very dry land.

NASA says its last stretch is a bit like a moat the Namib Desert can't cross: the wind blows sand and dust onto the river, which carries it out to sea. ESA notes that sand bars sometimes block the river's way into the Atlantic Ocean.

FEOW traces the Senqu from the northeast highlands, joined by tributaries such as the Senqunyane and Malibamatso, southwest through Lesotho's lowlands; as the Orange it flows westward through semi-arid and arid lands to the Atlantic.

NASA's 2005 Landsat feature on the last 100 km describes the river separating the dunes of the lower Namib Desert from the rocky landscape of northwestern Namaqualand, and calls it a moat the desert can't cross: winds that blow generally north to south pick up loose sand and dust, and the dust settles on the river, which carries it to sea. ESA adds that sand bars sometimes block its access to the ocean, so it is often called a river mouth rather than a true estuary.

High in the mountains lives a rare fish, the Maloti minnow.

Near the waterfall, springbok, kudu and giraffes live in the dry land.

In the highlands, FEOW says the Maloti minnow is found only in six high-altitude streams that feed the Orange, and describes it as critically endangered.

Around Augrabies Falls, South African Tourism lists springbok, gemsbok, kudu, klipspringer and giraffes, many most active at night when it is cooler, plus quiver trees and Verreaux's eagles. NASA says that each August to October, spring rains bring wildflowers to the dry land around the river's last stretch.

FEOW names one endemic fish in the Drakensberg-Maloti Highlands: the Maloti minnow (Pseudobarbus quathlambae), known only from six high-altitude tributaries of the Orange and described as critically endangered by habitat degradation and alteration and by competition with and predation by alien trout. Its high-altitude wetlands (bogs, sponges, tarns) occur elsewhere in southern Africa only in limited parts of the Eastern Cape.

In Augrabies Falls National Park, South African Tourism lists springbok, gemsbok, kudu, klipspringer, African wild cat, spotted genet and giraffe, rarely seen leopards and breeding Verreaux's eagles. Along the river's last 100 km, NASA notes a brief spring rainy season from August to October that brings wildflowers, while at other times of the year moisture may come only from Atlantic fog.

Near the river it can be very hot in summer and cold on winter nights.

Near water, wear a life jacket and stay with your grown-up.

South African Tourism says summer days at Augrabies Falls National Park average a searing 40 degrees Celsius, while winter nights often drop below freezing. It suggests visiting in autumn (April and May) or spring (September and October), with a sun hat, sunblock and warm clothes for the nights.

The US Centers for Disease Control and Prevention (CDC) says children should wear life jackets for all activities in and around natural water, such as rivers.

South African Tourism describes Augrabies as a low-rainfall area with extreme temperature swings: summer daytime averages of about 40 °C and winter nights often below zero. It recommends April-May and September-October and advises sun protection and layers. Activities include hiking trails and canoeing on the river.

The CDC advises that life jackets reduce the risk of drowning while boating for people of all ages and swimming abilities, that children should wear them for all activities in and around natural water, and that foam or air-filled toys are not safety devices.