Moving toward implementation: Basin-wide modeling and stakeholder platforms in the Incomati Basin

By Dominic Joaquim, Sansha van der Merwe, Ryan Nehring, and Jonathan Lautze

The Incomati River Basin supports around 2.3 million people, and is shared among the countries of South Africa, Eswatini, and Mozambique. The basin is home to the Kruger National Park, and contains key environmental resources, many of which are highly developed for irrigation, hydropower, and domestic supply. The basin faces considerable challenges in coping with droughts and floods, which are more pronounced in the downstream country of Mozambique. But cooperation over water has recently accelerated thanks toa multilateral agreement to establish the Incomati and Maputo Watercourse Commission (INMACOM), signed on 18 November, 2021, in Mbambane, Eswatini.

The CGIAR Initiative on NEXUS Gains has been in partnership with INMACOM for more than two years, providing technical support for integrated management of the Incomati's natural resources. One key focus of this collaboration is a basin-wide decision-support system (DSS), with another being the development of a multi-stakeholder platform (MSP). Both activities were the subject of a three-day workshop held from 19 to 21 November, 2024 in Mbombela, South Africa.

Bringing stakeholders together

Key stakeholders present at the event included INMACOM; the Inkomati-Usuthu Catchment Management Agency and the Department of Water and Sanitation (DWS), South Africa; the Komati Basin Water Authority of Eswatini and South Africa; joint river basin authorities from Eswatini; and the National Hydrologic Resources Management Agency and the Regional Water Administration, South, Mozambique. Together, these institutions represent stakeholder interests across the three countries of the Incomati-Maputo Basin.

In his welcome to workshop participants, Gideon Siziba, Director of Hydrological Engineering at the South African DWS, stressed the need for responsibly and sustainably sharing basin water resources. Initial presentations on the partnership between INMACOM and NEXUS Gains highlighted the progress made in both basin-wide modeling and the development of a multi-stakeholder platform.

Edward Mswane, Interim Executive Secretary of INMACOM, stressed that "the model developed by IWMI [International Water Management Institute], the University of Manchester, and the riparians supports the basin's planning for development and biodiversity conservation. The model informs management and operation, accounting for environmental flows, water transfers, and water uses." To close the opening session, Jonathan Lautze from IWMI outlined the impact of IWMI and CGIAR research, particularly in Southern Africa through work in the Incomati-Maputo Basin as well as that on integrated storage in the Shashe-Limpopo Basin.

Modeling scenarios for water allocation

Workshop presentations updated participants on the development of a Python water resources (Pywr) model to support optimal allocation of water resources. Mikiyas Etichia from the University of Manchester presented the model's co-development process in the basin, and Sansha van der Merwe from IWMI and the University of Witwatersrand shared insights on the simulated scenarios and key modeling results. Workshop discussions highlighted that while concerns do exist, the agreed minimum transboundary flow of 2.6 cubic meters of water per second is generally met at present. A key message from Ms van der Merwe's presentation was that modification of this agreed transboundary flow will bring minimal benefits when implemented in isolation. Addition of storage facilities, either with or without an alteration to the minimum transboundary flow, could potentially secure far greater benefits.

The results of different cross-country scenarios for water allocation, illustrating the varying impacts, proved helpful to participants. Oscar Sibia, Director of the Incomati River Basin Management Division at Mozambique's Regional Water Administration, South noted that "water sharing is a contentious issue globally, and it is important to evaluate different options to identify how best to utilize water among countries, communities, and sectors. NEXUS Gains research has played a valuable role in informing our water re-allocation discussions in the basin. Evidence generated through NEXUS Gains has already sparked a basin-wide discussion on dam operations since these have proven to be inefficient, at least in flood control."

Buyani Fakudze, Data Manager at INMACOM added that "currently we have no basin-wide decision-support system to guide dialogues on water allocation. The Incomati Pywr model developed among INMACOM, IWMI, and the University of Manchester is a critical tool which steers discussions on transboundary water re-allocation." To improve this model further, participants asked for the inclusion of climate change scenarios and more detail in dam-operating rules. Model handover to INMACOM is expected in 2025, following further training and capacity-building activities.

Developing a multistakeholder platform

Multistakeholder platforms are increasingly recognized as crucial institutions for improving stakeholder participation in nexus governance. At the NEXUS Gains workshop, Ryan Nehring from the International Food Policy Research Institute (IFPRI) outlined how MSPs enable stakeholder voices to be heard in a way that can affect policy, and that there are different approaches to designing and implementing MSPs: state-based (as in the Mekong Basin), semi-autonomous (the Nile Basin Discourse), and river basin organization-incorporated (the Zambezi Watercourse Commission).

Dominic Joaquim from Eduardo Mondlane University in Maputo, Mozambique proposed a design for the Incomati MSP. Participants from the three countries spent a full day discussing and agreeing on final text for the Incomati MSP guidelines, ensuring it is appropriate for their situation. These guidelines will be submitted to the INMACOM Council of Ministers for approval in 2025, with the Maputo Basin also included on request from INMACOM. Also, most importantly, participants agreed to have a two-level MSP: one where government officials, operators, and partners meets every six months; and another open forum in which a broader set of basin stakeholders meet once every year.

Sindy Mthimkhulu, CEO of the Joint River Basin Authorities' Project Board, Eswatini shared that "the value of this work lies not just in the platforms that are being produced. NEXUS Gains fostered cooperation between the three countries in a way that there is ownership in operational and government levels." In relation to the MSP, Edward Mswane noted that "the design of the MSP developed in partnership with NEXUS Gains has been invaluable. This will be adopted, and we believe it will serve as a model for MSPs in other shared waters. INMACOM will adopt it in the first half of 2025."

NEXUS Gains research has made a real impact in the Incomati-Maputo Basin. Indeed, Oscar Sibia notes "it is really commendable that this continuous cooperation was made possible, and that is thanks to the technical and financial support of NEXUS Gains. In my view, management of water resources should respond to stakeholder preferences using the water allocation model that is being developed. In that way, the decision-support system and MSP work hand in hand." Looking forward, it remains critical to see through to implementation both the basin-wide model and the MSP.

Dominic Joaquim is a Water and Climate Researcher at Eduardo Mondlane University, Maputo, Mozambique; Sansha van der Merwe is a Water Researcher at Wits University, Johannesburg, South Africa; Ryan Nehring is Associate Research Fellow, Natural Resources and Resilience Unit, IFPRI; Jonathan Lautze is Research Group Leader - Integrated Management of Basins and Aquifers, IWMI.

This work was carried out under the CGIAR Initiative on NEXUS Gains, which is grateful for the support of CGIAR Trust Fund contributors: www.cgiar.org/funders

Header image: Workshop field visit. Photo by Ryan Nehring.

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