skip to content

Cambridge Institute for Sustainability Leadership (CISL)

May 2021: Rivers and other freshwater systems sustain vital ecosystem services and livelihoods around the world. However, only 17% of rivers are both, free-flowing and in protected areas, with many rivers being at risk of further decline due to overfishing, pollution, flow alterations, and excessive water extraction. To reverse this decline, policy makers should elevate river protection to similar priority levels to marine and terrestrial protection, and explore new tools to support this.


Rivers and other freshwater systems provide vital ecosystem services and support livelihoods around the world. Despite representing only 1% of the Earth’s surface, they support more than half of all fish species and 13-20% of the global fish harvest. In addition to sustaining migratory fish, rivers also act as corridors and deliver sediment needed to maintain river deltas. These deltas are home to 500 million people and rivers protect deltas from sinking and shrinking. Nonetheless, only 17% of rivers are currently both, free-flowing and in protected areas, leaving many freshwater systems and the species that rely on them at risk. Freshwater species have already declined by 94% on average since 1970 with degradation of rivers due to shipping, over-fishing, and pollution being leading causes of their decline. Simultaneously, river systems are understudied and under-protected, while being at risk of further degradation due to poorly sited dam constructions, flow alterations, and excessive water extraction.

Implications and opportunities

Alongside maintaining river deltas, free-flowing rivers sustain freshwater biodiversity, fish protein in food supply chains, drinking water, industry, and have cultural significance. It highlights the importance of reversing river decline to ensure the future viability of rivers. This could be achieved by encouraging more protection, stimulating economic development in local river communities and fostering action from national governments, international institutions, private and public investors. In the lead-up to the UN’s Convention on Biological Diversity, COP15,  in October 2021 researchers are calling for river protection measures to be moved up the policy agenda. Protecting river systems could form part of international basin management strategies and environmental action plans. However, there is currently no global framework that specifically focuses on river or freshwater ecosystem protection and their protection frequently receives less attention than protection of marine or terrestrial systems. Protecting rivers is challenging since they cover long distances –  from upstream tributaries to downstream deltas –   often crossing several national borders with varying regulations. Parts of rivers flow through protected national parks, which could be extended along the banks of river systems beyond current park boundaries, but more tools will be needed to protect free-flowing rivers, including exploring the feasibility of granting river systems legal ‘personhood’.


The nature and size of free-flowing rivers makes their protection highly complex and multi-faceted. Therefore, further research will be needed to explore the efficiency and feasibility of tools or interventions that seek to protect rivers while safeguarding economic interests that are dependent on river access.


Perry, D., Harrison, I., Fernandes, S., Burnham, S. and Nichols, A., 2021. Global analysis of durable policies for free-flowing river protections. Sustainability, 13(4), p.2347.

Oppermann, J., (2021). One size does not fit all river: Diverse protection mechanism needed to keep them connected. Available at:

Townsend, C.,, Rights for nature: How granting a river ‘personhood’ could help protect it. Available at: