With a total catchment area of approximately a million square kilometres, the Orange-Senqu River basin is one of the largest in Africa, encompassing the whole of Lesotho and areas of Botswana, Namibia and South Africa.

The basin supports more than 14 million people and the river system plays a vital role in sustaining livelihoods and stimulating economic growth.

Demand for water is predicted to increase with economic growth and development, affirming the need for effective, efficient and sustainable water resources management to maintain these important ecological functions and secure the basin’s resources in the long term.

The governments of the four basin states are well aware of the critical scarcity of water resources in southern Africa and are committed to working together to protect these shared water resources and develop them in a sustainable and equitable way for the benefit of all their people.


Image-3Research has been carried out to fill knowledge gaps for the transboundary diagnostic analysis (TDA) and to determine the environmental flow requirements of the Fish and lower Orange rivers and estuary.  

A number of knowledge gaps were identified in the preliminary TDA and efforts have been made to fill some of these in. In particular:

  • the levels of POPs, PAHs and heavy metals in sediments, fish and the eggs of water birds were surveyed throughout the basin, providing a first approximation for many of these chemicals and health risk assessment (see Technical Report 21);
  • the hydrology of the basin was further analysed and recommendations were made for improved understanding of the basin’s water balance;
  • through cooperation with the Benguela Current Commission and their UNDP–GEF-funded strategic action programme, impacts of the Orange-Senqu River system on the marine and coastal environment were assessed (see Technical Report 1);
  • determination of the environmental flow requirements of the Fish and lower Orange rivers and estuary is currently being carried out to provide guidance to the basin states on strategies regarding the release of water from dams (a Study Website has for Environmental Flow Requirements of the Fish River and the Orange-Senqu River Mouth has been established for this initiative).


Demonstration projects

Three projects have been developed to test and demonstrate new techniques and methodologies to help address priority transboundary problems. Set locally, they are expected to provide best practices, lessons and potential solutions to problems at a basin-wide scale. They include:

  • rangeland management in south-eastern Botswana
  • rangeland management in Lesotho
  • water demand management and conservation in irrigation along the lower Orange.

Information from these studies is available in a number of publications and technical reports.


Rangeland management in south-eastern Botswana

botswanaThe project was started at the request of the Government of Botswana and works with the communities of two villages, Khawa and Zutshwa, in the southern Kalahari. It addresses rangeland management and the underlying causes of the problem through a number of activities and initiatives:

  • community-based monitoring of range condition
  • rotational grazing
  • rainwater capture
  • kitchen garden development
  • sand dune stabilisation
  • human–wildlife conflict mediation.


Rangeland management in Lesotho

lesothoThis project is being carried out in a number of locations near Mount Moorosi in Quthing District and is well-supported by local communities. It is expected to result in protection of rangelands from overgrazing that will lead to improved animal health and local livelihoods. This is being achieved by activities in two main areas:

  • Rehabilitation of rangelands by up-rooting invasive shrubs, harvesting grass seed and re-seeding the land, and construction of silt traps and stone lines on degraded slopes
  • Generating alternative income sources by introducing ‘keyhole’ kitchen gardening, poultry raising, and improved breeding stock for Merino sheep and Angora goats.



Water demand management and conservation along the lower Orange

lower-orangeWorking with a range of farmers from Noordoewer and Vioolsdrift, and the Joint Irrigation Authority (JIA) responsible for their shared irrigation scheme in this part of the lower Orange River (see, this project has been testing a number of different management approaches and technologies to assist in developing a water management strategy.  Activities include:

  • installation of soil moisture probes, meteo station, flow meters and other telemetry equipment to provide quasi real-time data online, allowing improved irrigation scheduling
  • training sessions and study tours with farmers to irrigation schemes in other parts of the basin, to encourage water demand management and water conservation at the farm and scheme level
  • drafting a water management plan for the irrigation scheme.


Technical Reports

Rangeland management in south-eastern Botswana

Rangeland management in Lesotho

Water demand management and conservation in irrigation along the lower Orange.

The ORASECOM Water Information System – WIS

Image-7The ORASECOM Water Information System – WIS – is a comprehensive information system on the Orange–Senqu River basin.

The WIS currently offers access to almost 40,000 files of data, documents and maps through a search facility, and a ‘water wiki’ whereby stakeholders can upload data and information from local surveys. Improvements are currently underway to enhance its functionality and its ‘look and feel’.  The WIS also profiles more than 100 other data custodians, with data and information holdings relevant to ORASECOM’s functions.

Access at

Technical Reports

Recommendations for transboundary environmental assessment


Working  closely with a respective working group and ORASECOM’s Legal Task Team, a document providing detailed guidance on requirements  regarding environmental assessments (EA) for activities that may have significant transboundary impacts has been drafted.

The document details procedural and documentary requirements for both environmental impact and strategic environmental assessments (EIAs and SEAs). It also includes detailed procedures for communication and collaboration between the basin states, a set of templates covering various components of the communication and notification process, and evaluation tools for EA reports.

It is expected that the recommendations will be applied to larger projects in the basin, as well as policies, plans and programmes, likely to have significant transboundary implications. It is hoped that the use of these recommendations will improve the way that EA tools are used and administered, strengthen their influence in decision-making processes and facilitate better cooperation and information-sharing during post-implementation compliance and monitoring the effectiveness of mitigation measures.

The first of its kind in the region, this document  will hopefully be beneficial in setting standards for undertaking EAs within transboundary river basins.  The report is due to published in  the final quarter of 2013.

Technical Reports

“Now I’ve made the decision to use a five-litre bucket to water the garden and the flowers to save water.”
Dora, Dobsonville.

For Children



Children are the basin’s future managers and decision-makers, so efforts are being made to raise their awareness regarding the Orange–Senqu River basin, its water resources and the challenges in conserving and managing these vital resources.

The project is assisting in the development of the Orange–Senqu River Learning Box – an educational tool for 10–12-year-old school learners. Teachers and learners from each of the basin states have been provided with field training on the use of miniSASS, a water quality monitoring tool. Two booklets are being produced for inclusion in the box.

Field training

Training on the use of miniSASS has been provided for teachers and learners from schools in participating in piloting the Orange–Senqu River Learning Box. These schools have been provided with equipment allowing them to monitor water sources in their area. They were also trained to upload their results to the water wiki allowing them to share them and other environmental data collected. The miniSass water wiki can be found at


Two publications for children were developed in the final quarter of 2013:

  • a booklet distilled from the transboundary diagnostic analysis (TDA) that explains the main environmental features and issues in the basin at a level suitable for children
  • an activity booklet to monitor catchment health, especially in the drier areas of the basin.

Transboundary diagnostic analysis (TDA)

Image-7Building on the preliminary TDA, work continues to fill knowledge gaps relevant to priority transboundary environmental problems and the integrated management of the basin’s water resources. The four most-pressing transboundary problems in the Orange–Senqu River basin have been prioritised as:

1) increasing water demand
2) declining water quality
3) land degradation and
4) changes to hydrological regime.

Through a participatory process, analysis of these transboundary problems with respect to their ecological and socio-economic impacts and immediate and underlying causes has helped identify potential points of intervention. These causal chain analyses (CCAs) and intervention points provide the springboard for national and basin-wide strategic planning.

A final TDA publication has been published. It provides a description of the basin and brings new information to the table, encompassing recent research and analyses on water balance, sediment loads, water quality, climate change and irrigated agriculture. Information is be more accessible through improved CCAs for easier interpretation and use, informative boxes on relevant issues and high-quality illustrations in the form of infographics, maps and photos.

Designed for managers, decision-makers and the serious student, the TDA will also be distilled into publications designed for the general reader and school children.

Technical Reports

National action plans and basin-wide strategic action programme

Image-4A basin-wide strategic action programme (SAP) and four national action plans (NAPs) are being developed through a participatory and consultative process with relevant stakeholders.

These strategic planning documents will outline agreed management responses to the priority transboundary water-related environmental problems identified in the transboundary diagnostic analysis (TDA). The NAPs will comprise of national component of basin-wide activities and specific national activities. They provide the vehicle to integrate basin-wide actions outlined in the SAP into national planning processes and budgets.

Key elements of these planning documents will be:

  • A description of environmental status and priority concerns
  • Rationale and objectives, including shorter-term (operational) targets and
    longer-term (strategic) targets
  • A coherent pipeline of projects
  • Implementation arrangements, institutions, time lines, resources and resource mobilisation, monitoring parameters.


Supporting Technical Reports