The Action Platform for Source-to-Sea Management (S2S Platform) is 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.

The S2S Platform is open to organizations committed to holistic management of land, freshwater, coasts and the ocean.

  • The Action Platform for Source-to-Sea Management, often referred to as S2S Platform, was formed in 2014, at the initiative of a group of committed partners.
  • Over the years it has successfully influenced policy dialogues as well as operational and financing strategies to better reflect the need for source-to-sea action. It has raised awareness and political attention to source-to-sea issues. And in the process, it has brought the freshwater and ocean communities together, and supported policy makers and practitioners through the development and dissemination of knowledge materials, policy briefs and practical tools.
  • Until the end of 2024 the Source to Sea Platform was hosted and coordinated by Stockholm International Water Institute (SIWI).
  • As of 1 January 2025 the S2S Platform is hosted and coordinated by the International Union for Conservation of Nature (IUCN). The former S2S Platform website will continue to house all S2S documents, products and information, but will not be further updated.

Since its formation in 2014, the S2S Platform has successfully highlighted the importance of a systems approach to ecosystem management through the development of the source-to-sea conceptual framework, analysing the linkages between SDG 6 and SDG 14.

It has also developed key guidance for implementers through Implementing the Source-to-Sea Approach: A Guide for Practitioners, and for its application in Source-to-Sea Framework for Marine Litter Prevention: Preventing Plastic Leakage in River Basins.

The Platform has seen increasing recognition of the need for a source-to-sea approach in key international processes, financing, and operational strategies.

The greatest strength of the S2S Platform continues to be the diversity and conviction of the partner network. The S2S Platform has grown into a network of more than 50 committed partners from around the world and across sectors.

“Source-to-sea management recognizes that there are linkages from land, to freshwater, the coasts and the ocean, creating a continuum from the source to the sea.”
Our Vision

We want to enable sustainable development across the land-freshwater-marine continuum through supporting the adoption and implementation of a source-to-sea approach to management at regional, national, and sub-national levels.

Our Mission

We envision a world in which land, fresh­water, coastal and marine resources are managed holistically, balancing benefits for the environment, communities and economy from source to sea.

Why Source to Sea management

The air we breathe, the food we eat and the climate on which our survival depends are all inextricably linked to source-to-sea systems. And the health of these systems depends heavily on the actions taken on land and along rivers.

Current governance, investments and operations are often developed from the perspective of a single sector or a single country or municipality, without consideration of how they might impact other parts of the source-to-sea system. Source-to-sea management takes a different approach.

All of our upstream activities compound one upon another, leaving virtually no coastal or marine area unaffected. This can be seen in the dead zones created by excess nutrients from agricultural runoff and untreated wastewater, and in sinking deltas because of sediment being trapped upstream. It can also be seen in excessive groundwater use and in plastic waste littering our beaches and oceans. Climate change further exacerbates these problems.

This is where source-to-sea management comes in. The vision of the Action Platform for Source-to-Sea Management is a world in which land, freshwater, coastal and marine resources are managed holistically, balancing benefits for the environment, communities, and economy – from source to sea. This source-to-sea continuum is linked by key aspects of the biophysical system, such as water, biota, sediment, pollutants, materials and ecosystem services. When any of these are altered in one part of the source-to-sea system, those alterations may have impacts either upstream or downstream of where they occur.

The impacts can be on the environment, or they can be social or economic in nature. The source-to-sea approach to management takes these upstream-downstream source-to-sea linkages into account, it takes a holistic view of the source-to-sea system, recognizing that doing so will result in greater benefits for people and nature.

By understanding the source-to-sea system as a whole, decisions are informed by upstream and downstream stakeholder interests. Trade-offs are considered to find the greatest mutual benefits across the entire source-to-sea system. Source-to-sea management also means that there is coordination between sectors to ensure coherence in policies and practice. Strengthening upstream-downstream cooperation and coordination across sectors can avoid unintended negative consequences and give rise to innovative solutions to addressing development challenges.

Applying a source-to-sea perspective when addressing the world’s development challenges increases the opportunity for truly sustainable change. The approach builds on existing frameworks, but broadens the scope beyond traditional and mostly independently managed land and water resources. To acknowledge that there is a strong interconnectedness between land, river basins, coasts, and the ocean, is fundamental – and it is urgently needed, as many development challenges are source-to-sea in nature.

The progress towards achieving the Sustainable Development Goals is being stalled by the absence of political commitment and a coherent approach. The source-to-sea perspective can counter this with its focus on interlinkages and the interdependencies between the SDGs. Such links are evident across the entire SDG agenda, but are particularly strong between SDG 6 on water, SDG 14 on oceans, SDG 15 on land-based ecosystems and SDG 13 on climate. The targets for these SDGs will not be met unless the fragmentation of management and governance structures are addressed.

Addressing development challenges posed by climate change, losses in biodiversity and global crises such as the COVID-19 pandemic need targeted action. But if development challenges are not tackled holistically, trade-offs between upstream and downstream stakeholders and across sectors will not be adequately addressed. Source-to-sea management allows for open and inclusive dialogues to be held, which will improve the success of policies, planning and investments.

The underlying principles of the source-to-sea approach allow it to be an effective solution to addressing the complexities of development challenges.

  • Holistic. It addresses upstream and downstream linkages across issues, stakeholders, desired outcomes, costs, and benefits.
    Collaborative. It builds on existing institutions, established methods and ongoing processes.
  • Prioritizing. It targets and addresses the issues that hold the greatest potential for generating positive impacts for the system.
  • Participatory. It engages upstream and downstream stakeholders from different sectors and raise awareness about the impact of human activities.
  • Context dependent. It is derived from, and responsive to, the local context.
  • Result-oriented. It targets intermediate outcomes that contribute to overall improved economic, social, and environmental status.
  • Adaptive. It is based on learning-by-doing through pragmatic implementation, monitoring, evaluation, and adaptive management.

How the Platform works

The activities of the S2S Platform are supported by a secretariat, hosted by the International Union for Conservation of Nature (IUCN). The secretariat helps to maintain a community of committed source-to-sea advocates through facilitating partner engagement activities and supporting collaborative activities.

The Steering Committee, elected from among the partners, guides the direction of the S2S Platform. It identifies annual priorities and take a leading role in promoting the source-to-sea approach by engaging its collective networks.

  • Tom Panella, Chair
  • International Union for Conservation of Nature (IUCN), James Dalton, Director IUCN Global Water Programme
  • Intergovernmental Oceanographic Commission UNESCO (IOC/ UNESCO), Julian Barbiere, Head, Marine Policy and Regional Implementation Section
  • International Water Resources Association (IWRA), Callum Clench, Executive Director
  • Deltares, Audrey Legat, Senior Advisor Water Governance
  • United Nations Development Programme (UNDP), Mary M. Matthews, Head, UNDP Water and Oceans i.a. UNDP Ocean Advisor and Ocean Innovation Challenge Manager
  • United Nations Environment Programme (UNEP), Heidi Savelli-Soderberg, Chief a.i., Source to Sea Pollution-Free Unit, Ecosystems Division
  • Global Water Partnership (GWP), Dimitris Faloutsos, Deputy Regional Coordinator Global Water Partnership – Mediterranean (GWP-Med)
  • Plymouth Marine Laboratory, Andy Rees, Senior Scientist
  • International Capacity Development Network for Sustainable Water Management (Cap-Net), Yasmina Rais El Fanni, Senior Programme Officer
  • Stockholm International Water Institute (SIWI)

With the Strategy 2021-2025, we set our sights on advancing the implementation of the source-to-sea approach and application of source-to-sea perspectives. The aim is to achieve the ambitions of the 2030 Agenda by influencing policy makers, assisting practitioners, and growing understanding on the needs for and benefits of source-to-sea action.

Our goals:

  • In 2025, the S2S Platform will have active, engaged partners representing the diversity of actors needed to fulfil our vision.
  • The S2S Platform establishes a global source-to-sea knowledge hub.
  • Source-to-sea perspectives hold a permanent place in the global agenda as a solution to rising and persistent development challenges.
  • Expertise is built and source-to-sea management is applied in six continents.

Strategic aims

1. Strengthening partnership across actors and initiatives

Through individual and joint activities, we will engage our extensive networks and connect with relevant initiatives promoting source-to-sea policies and practice; thereby building understanding, commitment and action to address source-to-sea issues.

We recognize that achieving our vision relies on using our collective and individual strengths. We commit to working together as a Platform to forge new knowledge, expand our influence and increase source-to-sea action.

As partners, we work together to strengthen partnership by:

  • Building a stronger and united S2S Platform through regular engagement activities that increase connectivity, collaboration and knowledge sharing among partners and our extended community.
  • Attracting strategic partners and supporters from across the source-to-sea continuum with increasing engagement from land-based and marine actors as well as actors who can support local implementation such as the private sector and civil society.
  • Growing a vibrant source-to-sea community that expands source-to-sea action by leveraging our collective resources, networks and expertise.
  • Securing a stable source of funding for the S2S Platform Secretariat and its activities.

This is supported by:

  • Participation in the S2S Platform has expanded to include a diversity of sectors and regions, transboundary organizations and actors along the land-freshwater-­marine continuum.
  • Partners take an active, catalytic role in delivering the four strategic aims, realizing and contributing to greater progress than would have been possible as individual organizations.
    Partners connect regularly through S2S Platform partner engagement activities.
  • Partners regularly share source-to-sea news to be disseminated by the platform and disseminate platform news through their own communications networks.
  • Multi-year funding for the S2S Platform Secretariat and its activities is secured.

2. Growing understanding

We will substantiate the need for and benefits of the source-to-sea approach and increase the understanding of source-to-sea linkages by gathering and sharing knowledge, building an evidence-base gained through research, and developing guidance on addressing source-to-sea challenges.

We recognize that source-to-sea action starts with understanding the benefits of addressing development challenges from source to sea, building a strong knowledge base of its merits and challenges, and identifying barriers to implementation as well as the means to overcome them.

As partners we will work together to grow understanding by:

  • Developing knowledge resources that help overcome barriers to source-to-sea management and guide implementation of the source-to-sea approach in a variety of contexts and development challenges.
  • Building the case and evidence-base for a source-to-sea approach as a necessary and credible response to rising and persistent development priorities at regional, national and sub-national levels by collecting and analysing cases, research, data and lessons learned from implementation in different contexts, as well as strengthening the understanding of trade-offs when linking across the land-fresh water-marine continuum.

This is supported by:

  • Participation in the S2S Platform has expanded to include a diversity of sectors and regions, transboundary organizations and actors along the land-freshwater-­marine continuum.
  • Partners take an active, catalytic role in delivering the four strategic aims, realizing and contributing to greater progress than would have been possible as individual organizations.
    Partners connect regularly through S2S Platform partner engagement activities.
  • Partners regularly share source-to-sea news to be disseminated by the platform and disseminate platform news through their own communications networks.
  • Multi-year funding for the S2S Platform Secretariat and its activities is secured.

3. Building commitment for action

We will inform and influence global, regional and transboundary agenda setting and the priorities of governments, financiers, private sector and civil society to effectively address source-to-sea issues in policy and practice.

We recognize that getting more source-to-sea action on the ground requires commitments from governments, financiers, private sector and civil society to address development challenges from source to sea.

As partners, we build commitment by:

  • Supporting regional cooperation between freshwater and marine actors to address the transboundary nature of source-to-sea systems.
  • Ensuring source-to-sea perspectives are well featured and advocated for in relation to key issues such as achieving the 2030 Sustainable Development Agenda, delivering on the Paris Agreement and the post-pandemic recovery through our active participation in prominent global, regional and transboundary policy processes.
  • Engaging high-level and influential spokespersons to ensure that source-to-sea perspectives are championed and well considered in global, regional and transboundary processes.
  • Raising awareness of the benefits of source-to-sea action, and its required enabling environment through dialogue with national and sub-national actors to encourage its uptake in policy and practice.
  • Working with financiers, such as development banks, to incentivize financial mechanisms and investment tools that guide the consideration of upstream downstream linkages and the viewpoints of stakeholders along the land-freshwater-marine continuum.

4. Taking action on the ground

We stimulate source-to-sea action by raising awareness from grassroots to national levels, building local and regional capacity and demonstrating its benefits in addressing development challenges through practical application.

We recognize that getting source-to-sea action on the ground relies upon increasing demand from grassroots to national levels, building local capacity through providing training, tools and guidance and demonstrating benefits in addressing development challenges from source to sea.

As partners, we support action of the ground by:

  • Raising awareness of the benefits of source-to-sea management in addressing the trade-offs that can arise from upstream-downstream linkages, contributing to an increase in demand from grassroots to national levels for taking a source-to-sea approach to addressing local priorities.
  • Building local capacity among public, private and civil society actors to address upstream-downstream linkages and facilitating cross-sectoral coordination.
  • Increasing local and regional expertise in implementing the source-to-sea approach through interactive workshops and other training modalities, enlarging the overall number of source-to-sea practitioners.
  • Demonstrating the benefits of the source-to-sea approach to management by applying it in response to local priorities in a variety of contexts.

This is supported by:

  • Local and regional capacity is built through capacity development activities, contributing to an increased awareness among upstream and downstream stakeholders about the benefits of a source-to-sea approach, building implementation demand from the grassroots to national levels and ensuring that expertise is readily available to drive implementation.
  • Knowledge resources are developed to support the adoption of the source-to-sea approach at regional, national and sub-national levels.
  • A strong case for source-to-sea approaches to management has been made through projects conducted in different regions and addressing a range of source-to-sea issues.

Publications

Reports, case studies and handbooks

Guidance Note for the Implementation of Source-to-Sea Management in Transboundary Basins
  guide     s2s  
FileAction
EnglishDownload
Source-to-sea and landscape approaches
  s2s  
FileAction
EnglishDownload
PortugeeseDownload
S2S 2023 Progress Report
  Report     s2s  
FileAction
EnglishDownload

Outreach materials

Brochures, infographics and visual storytelling

Source-to-sea and landscape approaches - factsheet
  Factsheet     s2s  
FileAction
EnglishDownload
Cover of On the Verge of a New Water Scarcity
On the Verge of a New Water Scarcity
  policy brief     s2s  
FileAction
EnglishDownload
Cover of Starting at the source to save the ocean
Starting at the source to save the ocean
  policy brief     s2s  
FileAction
EnglishDownload

Videos

Audiovisual materials

Piloting the source-to-sea approach in Vu Gia-Thu Bon River Basin - Viet Nam
  s2s     Video  
A changing climate from Source-to-Sea: Nature-based Solutions in transitional waters
  s2s     Video  
Piloting the source-to-sea approach in Lake Hawassa - Ethiopia
  s2s     Video  

The Source to Sea Platform was until the end of 2024 funded by the generous support from the Government of Sweden and the United Nations Development Programme (UNDP)