The Basin

From its mountain source in Lesotho, the Orange-Senqu River fans out like a network of life-giving arteries, supporting some of the most fragile and endemic biomes, including the Nama Karoo, Namaqua and the Richtersveld in South Africa, the Southern Kalahari of Botswana and the Namib Desert of Namibia.

There are a total of five wetlands of international importance registered with Ramsar across the Basin, only one of which is located in Lesotho. Wetlands are typically biodiversity hotspots that support a large variety of birds and animals and sometimes host unique breeding sites for birds.

The Orange River is the most recognisable feature of the basin, changing its name from Senqu in Lesotho to Orange in the rest of the river basin. It is highly engineered, with multiple dams and tunnels to move the water to where it is needed.

Managing the transboundary Orange-Senqu River Basin collectively

As the most important river in Southern Africa, shared between four countries, protecting the source of the Orange-Senqu River in the Mountain Kingdom of Lesotho is critical.

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How is Lesotho’s national movement and programme, ReNOKA, doing things differently to protect land and water resources in the Orange-Senqu River basin?

The Maloti Mountains that dominate Lesotho’s landscape are part of the Drakensberg escarpment, both forming part of the Maloti-Drakensberg Transfrontier Conservation Area. This ancient mountain range can trace its birth back 180 million years when volcanic eruptions built the mountains from layers of hard basalt rock.

Lesotho’s terrain is so old that dinosaur footprints from some of the largest carnivores that ever lived have been found there, alluding to a time when vegetation was abundant enough to support the theropod’s prey.

Millenia later when the hunter-gatherer Khoi-San occupied the sandstone caves close to the Mohokare River, rock art depicting great herds of eland, elephant and crocodiles thriving in the area, prove that water and food supported a diversity of wildlife just 12 000 years ago.

From the diaries of European missionaries who came to “Basutoland” over two centuries ago, observations of vast acacia forests covering the slopes prove that deforestation is a recent phenomenon and human activity continues to alter the landscape.

Lesotho continues to enjoy high rainfall and snow with up to 1 500mm per year, supporting the unique Afro-Montane biome. The water mythologies of the traditional Basotho live on. Water and the animals that live in it are inextricably linked to life and the circle of life and death.

Lesotho contributes over 40% of the total volume of the Orange-Senqu River Basin from a land base of just 3%.

As droughts and floods become increasingly frequent as a result of climate change, ReNOKA, with the help of ORASECOM, aims to restore critical sub-catchments in Lesotho to support the most vulnerable communities and build a more climate-resilient Orange-Senqu River Basin.

Not only must Lesotho protect its water resources for its own domestic water, food and energy security, but also to meet its transboundary agreements with states that share the river. In 1986, Lesotho and South Africa signed a treaty outlining the bulk water transfer agreement that underpins the Lesotho Highlands Water Project.

Explore case studies and success stories of transboundary collaboration in the Orange-Senqu River Basin and the Southern African region.

These big rivers have been divided into six catchment management areas for the purpose of strategic planning, namely the Upper, Middle, and Lower Mohokare, Upper and Lower Senqu, and Makhaleng catchment management areas. ReNOKA and the catchment stakeholders are developing Integrated Catchment Management and Development Plans (ICMDPs) for each of these catchment management areas. These plans will give strategic guidance for a timeframe of five to ten years and will promote climate resilient and sustainable interventions. Development of the first two of these plans for Upper Mohokare and Makhaleng catchments has started in 2023.

The six catchment management areas are subdivided into 74 smaller sub-catchments. These form the management units for ReNOKA and the Lesotho Government. Within these sub-catchments ReNOKA supports the development and implementation of bottom up, community-driven annual Community Council Integrated Catchment Management Action Plans. These plans aim at addressing the human causes of catchment degradation such as unsustainable land use practices, advance climate resilience and improve livelihood opportunities for local communities.

ReNOKA has piloted activities including local planning processes and rapid watershed rehabilitation measures in six of these smaller sub-catchments:

1. Khubelu, 2. Likhetla, 3. Hlotse, 4. Makhalaneng, 5. Maletsunyane, and 6. Senqunyane

Based on lessons learnt in the pilot sub-catchments, ReNOKA is scaling up to 12 new sub-catchments across Lesotho.

The Vaal River, which is the largest tributary of the Orange River in South Africa, has been dammed several times since 1923 and the Vaal Dam wall has been raised twice to increase its storage capacity.

The city of Johannesburg remains the biggest user of the Orange-Senqu River Basin. Founded in 1886 after the discovery of gold, Johannesburg or eGoli is the only mega city in the world not built on a river. As a result, it is heavily dependent on water imports.

The population of Johannesburg is highly contested as the official figure of 8 million people often excludes informal settlements populated with economic migrants. Some population figures include Soweto – bringing the population to 12 million. In 2011, residents of Johannesburg used 349 litres of water per day, almost double the usage of any other African city.

The Lesotho Highlands Water Project (LHWP)

LHWP is a highly engineered transfer scheme which moves water from the Lesotho Highlands to South Africa’s industrial hub of Gauteng, via the Ash River fallout. The entire project was conceived in four phases, envisioning five storage dams and 200 kilometres of transfer tunnels.

The first phase, completed in 2004, resulted in the 185-metre-high Katse Dam and the 72-megawatt Muela Power Station, providing electricity to Maseru. The second phase included the Mohale Dam and another 32-kilometre transfer tunnel connecting Katse and Mohale.

The Lesotho Highlands Water Project was awarded the ‘Most outstanding engineering achievement of the century’ by the South African Institute of Civil Engineering.

Even though the construction of the dams has flooded 2 000 – 5 000 hectares of arable land and households had to be resettled, the dams also generate revenues and energy security for Lesotho.

Phase two is currently underway. It will result in the Polihali Dam, due for completion in 2026.

But in the south, Botswana is dominated by the Kalahari Desert and the Makgadikgadi Pans – the remnants of an inland sea. After just a few inches of rain, the pans explode with algal blooms that attract large flocks of lesser flamingos, while supporting the largest zebra migration south of the Serengeti.

Botswana, historically a British protectorate, was a deeply rural country depending on cattle farming for its economy before the discovery of diamonds in 1964. Despite tourism and mining revenue eclipsing beef exports as a GDP earner for the country, Botswana continues to farm beef mostly because of the country’s pastoral culture and the historic Lomé Agreement that offered favourable subsidies to Botswana for its beef exports to Europe.

Botswana is a member of three important transboundary river basins, including the Okavango, the Limpopo and the Orange-Senqu. But as a result of heavy industries such as mining and energy, water demands outstrip supply and the country may run out of water by 2025 unless new water is brought into the system.

A plan to transfer water from Lesotho to Botswana is underway. The Lesotho-Botswana Water Transfer (L-BWT) Scheme will supply water to Botswana, Lesotho and South Africa from the Makhaleng Dam – part of the Lesotho Lowlands Water Supply Scheme – through a transfer tunnel extending for 700km from Lesotho to Botswana.

Botswana’s Molopo River begins in Botswana but flows south west to join the Orange River at Mahikeng.

As a result of the many dams impounding the Orange River upstream, including the Gariep and the Vanderkloof Dams, the flows have been significantly reduced over time.

The Orange River Mouth was recognised by Ramsar as a wetland of International importance in 1995, when its role in supporting the fish stocks on the Atlantic Coast, providing a habitat for breeding birds like flamingos and protecting the river from salt water intrusion, became apparent.

ORASECOM and the Benguela Current Commission (BCC) in Namibia are good examples of how regional cooperation can support integrated catchment management of the river. These two river commissions now ensure that the estuary is flooded every year by regulated releases.

A further dam is proposed at Vioolsdrift in South Africa that will help regulate floods for the lower Orange River and construction will begin in 2024.

The Orange River in the Northern Cape province of South Africa nourishes the Namaqualand and Richtersveld biomes, shared between South Africa and Namibia, each hosting unique plant and animal species that survive in harsh, arid conditions. The quiver tree, for example, is a slow growing succulent with suede-like bark, named by the Khoi San who used the skin to hold their hunting arrows. The tree has since become an indicator species to track climate change as it offers a climate record of over 700 years in some trees.

Namibia’s Fish River, best known as the largest river canyon in Africa, splinters to form the Orange River, which extends for 160km and is 550m deep at some points. The Fish River Canyon relies on significant rain events to flood and is mostly dry, but its size and depth does offer a glimpse into the past, when Namibia was certainly not a desert.