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NB-ITTAS in 2025:

Conjunctive water resources management, and transboundary cooperation

By IW:LEARN

December 18^th, 2025

From Field Pilots to Shared Groundwater Governance

In 2025, the Sahara and Sahel Observatory (OSS) took a decisive step in translating years of joint knowledge-production on the Iullemeden–Taoudéni/Tanezrouft Aquifer System (ITTAS) into concrete field impact and stronger regional cooperation.

While six national demonstration pilots moved into full implementation, NB-ITTAS also accelerated the exchange of best practices, training of trainers and high-level advocacy on transboundary aquifers. Together, these strands have laid the groundwork for a more resilient and cooperative future for groundwater in the Sahel and West Africa.

1. Key highlights and achievements from 2025

Demonstration pilots: from concepts to concrete benefits

Mauritania – Dhar Basin (Chegga El Beidha & Terbekou)

In Mauritania, a technical supervision mission to the Dhar basin in late October 2025 confirmed major advances in climate-resilient water access for agro-pastoral communities and transhumant herders.

Key achievements included:

Solar-powered boreholes supplying drinking water and supporting agro-pastoral activities in Chegga El Beidha and Terbekou.
Community-based solutions to reduce high iron content and improve drinking water quality.
Water-efficient agriculture, including solar-powered irrigation and protected cropping systems, helping diversify and secure local food production.

These interventions directly support vulnerable communities along a key transhumance corridor, reducing pressure on existing wells and helping to prevent conflicts around water.

Burkina Faso – Kou Basin (near Bobo-Dioulasso)

In the Kou basin of Burkina Faso, NB-ITTAS pursued a comprehensive approach that combines groundwater recharge, water supply and ecosystem restoration. A supervision mission conducted with national partners highlighted several tangible results:

Solar-powered boreholes and elevated reservoirs, improving reliable access to potable water.
Market-garden wells, supporting local food production and livelihoods, particularly for women’s groups.
Restoration of riverbanks along the Houet through sanitation and vegetation management, helping to reduce pollution and protect recharge zones.
Local waste-management initiatives, emerging as promising examples of participatory governance.

These actions collectively contribute to improved groundwater quantity and quality, while reinforcing local ownership and climate resilience.

Other ITTAS pilot sites

Across the other pilot countries, the project continued to operationalise context-specific solutions:

Benin (Kandi basin) – management of extreme alternation between droughts and floods, using surface-water control structures and market-garden wells to reduce pollution risks from latrines and enhance recharge.
Mali (Delta Intérieur du Niger – Dalladougou) – nature-based solutions (tree planting, stone bunds, a demonstration subsurface dam) combined with solar-equipped domestic and productive water points, and strengthened community water committees.
Niger (Dallols and irrigated valleys) – participatory monitoring of groundwater quality and vulnerability, with a focus on nitrate contamination and salinization in intensively cultivated zones.
Nigeria (Wamakko – Sokoto-Rima basin) – Managed Aquifer Recharge (MAR) through an infiltration pond and injection wells, designed to capture wet-season flows and restore dry-season groundwater availability, alongside awareness-raising on pollution and over-abstraction.

Together, these pilots form a living laboratory of technical and institutional options for recharge enhancement, pollution control, and inclusive groundwater governance in arid and semi-arid contexts.

Building a community of practice on shared groundwater

Abuja, Cotonou and Niamey regional workshops – Pollution and mineralisation, Groundwater recharge, water availability and adaptation to climate change

In September, October and December 2025, Abuja, Cotonou and Niamey hosted respectively the First, Second and Third regional workshops on best practices, dedicated to pollution and high mineralisation of groundwater in the ITTAS system, Groundwater recharge and increasing access to water, and adaptation to climate change. Representatives of the six ITTAS countries, the Niger Basin Authority (NBA) and regional partners presented their pilot experiences on:

Successful recharge interventions in Mali, Mauritania, Niger, Burkina Faso, Benin and Nigeria;
Direct impacts on health, agriculture and livelihoods through improved access to groundwater;
The importance of joint learning and cross-border cooperation for scaling up effective solutions across the Niger Basin and ITTAS.
Reducing microbiological and chemical pollution;
Managing excessive iron, fluorides and salinity;
Strengthening local governance around sensitive abstraction and recharge zones.

The workshops laid the foundation for a Regional Compendium of Good Practices, designed as a reference tool for countries and partners when designing groundwater quality interventions and policies. The workshops also confirmed the value of NB-ITTAS as a platform for exchanging methods on MAR, conjunctive management of surface and groundwater, and community-based monitoring.

Tunis regional training – Conjunctive management of surface and groundwater

In Tunis, OSS also convened a regional training of trainers on conjunctive management of surface and groundwater, in partnership with Cap-Net. The course brought together university lecturers and national experts to deepen their skills in:

Aquifer systems and data integration;
Transboundary cooperation and governance mechanisms;
Climate change adaptation approaches linked to groundwater.

This capacity-building track is crucial for embedding NB-ITTAS methodologies in national institutions, training programmes and future projects.

Regional training-of-trainers workshop on conjunctive water resource management in Tunis.

From regional dialogue to global influence

The project results were shared at major international events, including:

High-level plenary at the World Water Congress – Marrakech

On 3 December 2025, OSS took part in the High-Level Plenary on water governance at the 19th World Water Congress in Marrakech.

During this session, OSS highlighted:

The centrality of integrated water resources management and strong institutions for transboundary basins;
The role of NB-ITTAS and SMAS projects, financed by the GEF through UNEP, as concrete demonstrations that co-produced knowledge and co-managed aquifers can sustain durable, replicable cooperation;
The importance of joint data-sharing mechanisms and regional information systems for shared aquifers.

This participation reinforced OSS’s role in global debates on water governance and climate resilience, while showcasing ITTAS as a flagship example from Africa.

7th SADC Groundwater Conference – Johannesburg

Later in November 2025, the 7th SADC Groundwater Conference in Johannesburg provided another platform to share lessons from NB-ITTAS and SMAS.

Representing OSS, the Director of the Water Department, Mr Mohamedou Baba Sy, emphasised:

The importance of conjunctive management of surface and groundwater;
The need for nature-based solutions, better data and adapted governance frameworks;
The contribution of OSS, as a member of AMCOW’s Task Force, to the Strategic Programme on Groundwater for Water Security and Resilience (SPGWR).

By linking Sahelian aquifer management to continental initiatives in Southern Africa, NB-ITTAS helps position shared groundwater as a cornerstone of Africa’s climate and water security agendas.

Consolidating achievements and preparing NB-ITTAS Phase II

Regional workshop and vision for the future

In September 2025, the regional NB-ITTAS workshop marked the close of Phase I (2018–2025) and confirmed a strong collective commitment to sustainable, shared groundwater management in the Sahel.

Phase I has delivered:

A regional hydrogeological model for ITTAS;
A Transboundary Diagnostic Analysis (TDA) and Strategic Action Programme (SAP);
Six national demonstration pilots on priority themes (recharge, pollution, conjunctive management, quality and access);
A database of more than 57,000 water points;
A Memorandum of Understanding establishing a Consultation Mechanism for shared groundwater;
Strengthened national technical capacities and communication strategies.

Writeshop for Phase II – Turning knowledge into long-term action

Immediately after the closing workshop, a strategic writeshop was held in Tunis to develop the concept note for NB-ITTAS Phase II, to be submitted to the GEF through UNEP.

Experts from Benin, Burkina Faso, Mali, Mauritania, Niger and Nigeria jointly outlined a new phase that would:

Build on the tangible field results and governance advances of Phase I;
Scale up best practices on recharge, pollution control and quality management;
Deepen regional cooperation mechanisms and data-sharing;
Integrate emerging priorities on climate resilience, water security and sustainable development.

The ambition is clear: transform the knowledge and experiences generated since 2018 into long-lasting, large-scale benefits for people and ecosystems across the Sahel.

Throughout 2025, NB-ITTAS confirmed its dual nature as both a field laboratory and a regional cooperation platform:

On the ground, demonstration pilots are improving access to water, enhancing recharge, reducing pollution and supporting climate-resilient livelihoods in vulnerable Sahelian communities.
At regional and global levels, workshops, trainings and high-level events are building a shared culture of groundwater governance, grounded in science, participation and solidarity.

By linking local solutions with regional strategies and global advocacy, OSS and its partners are helping to ensure that the ITTAS aquifer system becomes not only a lifeline for rural populations but also a model of cooperative, climate-resilient groundwater management in Africa and beyond.

Thus, we can conclude that :

• Strengthened regional cooperation on transboundary water and ecosystems management

The project successfully facilitated coordinated exchanges between participating countries, helping harmonise approaches for managing shared water resources through nature-based solutions (NbS), including Conjunctive Water resources management. The ministerial meeting consolidated the foundations for the establishment of a framework for the Consultation Mechanism. This includes joint field missions, technical workshops, Ministerial meetings and the establishment of transboundary working groups.

• Advancement of NbS demonstration activities and pilot interventions

Pilot sites implementing restoration, wetland management, erosion control, or sustainable land–water practices showed significant progress. Early results indicate improved ecosystem resilience, enhanced water retention, and stronger community engagement.

• Capacity building and knowledge-sharing milestones

Over the year, the project delivered specialised training modules on decision-support tools, climate adaptation strategies, monitoring methodologies, and NbS design. These activities strengthened institutional capacities and improved alignment with regional and global frameworks (e.g., SDG 6, Kunming-Montreal GBF).

• Improved data, tools, and decision-making support

Progress was made on harmonising data collection, improving assessments of ecosystem services, and developing geo-information tools that support evidence-based planning and governance.

2. Year-in-review reflections from your project or team

• Growing recognition of NbS and Conjunctive Water resources management as a unifying approach

Throughout 2025, the team observed an increased commitment from institutions and partners to adopt NbS and Conjunctive Water resources management approaches as cost-effective and socially inclusive solutions to climate and water challenges.

• Importance of multi-stakeholder coordination

One key lesson was the necessity of early and continuous engagement of ministries, basin authorities, local communities, and scientific institutions. This strengthened ownership and facilitated smoother implementation.

• Need for flexibility in project implementation

Climate-related disruptions, administrative procedures, or delays in field activities highlighted the value of adaptive planning and agile management approaches.

• Enhanced visibility and strategic positioning of the project

Through active participation in regional forums, COP events, and IW:LEARN exchanges, the NB-ITTAS project increased its profile and contributed to global discussions on water–ecosystem linkages.

3. Updates you would like the IW community to carry into 2026

• Accelerating the integration of nature-based solutions and Conjunctive Water resources management in transboundary water governance

The project encourages IW partners to prioritize NbS and Conjunctive Water resources management in basin planning, investment pipelines, and national adaptation strategies, highlighting their co-benefits for climate resilience, biodiversity, and livelihoods.

• Expanding regional and inter-basin collaboration

In 2026, stronger ties between river basin organizations, scientific networks, and GEF IW projects will be essential for knowledge exchange and scaling successful models.

• Continuing support for data harmonization and digital tools

Shared data platforms, monitoring systems, and decision-support tools remain priorities for improving coordinated action across borders.

• Strengthening community engagement and gender-responsive approaches

2026 efforts should reinforce inclusive participation, recognizing the critical role of women, youth, and local communities in sustaining NbS and Conjunctive Water resources management interventions and governance reforms.

• Mobilizing financing for NbS, Conjunctive Water resources management and climate-resilient water management

Building partnerships with donors, private actors, and governments will be key for ensuring long-term sustainability and scaling up successful pilot actions.

About the NB-ITTAS project

The NB-ITTAS Project supports sustainable water management in the Niger River Basin and the Iullemeden-Taoudéni/Tanezrouft Aquifer System (ITTAS) across 11 African countries. Led by OSS, NBA, UNESCO, and UNIDO, it promotes knowledge-based IWRM and strengthens water governance for community and ecosystem resilience. Key achievements include a validated TDA/SAP, hydrogeological modelling, and six pilot sites testing best practices in groundwater management, pollution control, and climate adaptation. The project contributes to SDGs 2, 6.5, and 13, and demonstrates scalable solutions to transboundary water challenges in the Sahel.