Operationalising the Source-to-Sea approach in the Ganga-Brahmaputra-Meghna Basin through the UN Global Water Conventions

Background and concept

Traversed by the three great river systems, the Ganga-Brahmaputra-Meghna (GBM) Basin sustains lives, livelihoods and biodiversity by providing a range of ecosystem services. Together, these rivers drain an area of about 1.75 million square kilometres, home to more than 630 million people over five countries: Bangladesh, Bhutan, China, India and Nepal. However, high population density, poorly planned development and fragmented water management have left the basin facing significant challenges, including worsening pollution, biodiversity and habitat loss, extreme climate events, landslides and recurring floods.

These pressures generate large volumes of pollutants and sediments that are carried downstream and into the sea, threatening marine life and the livelihoods of coastal communities. Compounding this, large water resource development projects and flood control measures regulate flows in ways that prevent rivers from performing their essential ecological functions, such as maintaining the natural balance of estuaries. Despite the clear connections between these upstream and downstream impacts, a holistic approach linking the governance of river ecosystems with coastal and marine ecosystems remains absent.

The Source to Sea (S2S) approach recognises that land, rivers, coasts and oceans are all connected, and that the health of one directly affects the others. It acknowledges that the wellbeing of communities living along these ecosystems depends on managing them together rather than in isolation. Crucially, S2S looks at impacts in both directions: the effect that activities on land have on downstream ecosystems, and the ways in which changes downstream can ripple back upstream.

Despite its relevance, the S2S approach remains little known in the GBM region, limiting its practical application. The absence of a basin-wide cooperative framework in the GBM presents an opportunity to explore how S2S principles could be introduced and implemented.

International water law offers a useful starting point. The UN Water Convention (the Convention on the Protection and Use of Transboundary Watercourses and International Lakes, 1992), recently acceded to by Bangladesh, explicitly includes the protection of the marine environment among its objectives. Its core principles - transboundary cooperation, sustainable management, the precautionary principle and the polluter pays principle - closely align with the S2S approach. The Convention also provides practical guidance for GBM countries, including measures to reduce land-based pollution affecting coastal areas, cooperation to protect the marine environment, and frameworks for involving coastal states in joint governance bodies.

The S2S approach also has an important role to play in achieving the UN Sustainable Development Goals (SDGs). It can accelerate progress toward four goals in particular: SDG 6 (Clean Water and Sanitation), SDG 13 (Climate Action), SDG 14 (Life Below Water) and SDG 15 (Life on Land).

IUCN hosts the Source-to-Sea Management (S2S Platform) Action Platform, a multi-stakeholder initiative to exchange and generate knowledge, and support joint action for improved management of land, water, coastal and marine linkages. The S2S Platform strengthens partnerships between sectors and expands the understanding of source-to-sea challenges and of the solutions that will lead to sustainable development. It builds commitment so that policies and finance stimulate source-to-sea action on the ground.

It is in this context that a three-part webinar series has been organised to explore the S2S approach in the context of the GBM Basin.

Registration available here.

Webinar I: Enabling Source-to-Sea in the GBM Region: Introduction to the concept, relevance and linkages with the UN Global Water Conventions 
Webinar II: From Concept to Practice: Combating Plastic Pollution in the GBM Basin through Source to Sea lens using principles of UN Global Water Conventions as a framework
Webinar III: Mainstreaming Ecosystem‑based and Source‑to‑Sea Approaches for IWRM and SDG 6, 13, 14, 15 and Beyond in the GBM Basin – Strengthening capacity and institutional coherence

This webinar series invites all participants to uncover the Source-to-Sea approach and its application in the Ganga-Brahmaputra-Meghna Basin.

The series is being convened by IUCN and the Green Trial Law Group - a law firm specialising in water cooperation instruments in South Asia – with funding from IUCN BRIDGE and supported by the Secretariat to the UN Water Convention.