Dive into the Healthy and Productive Lakes Portal! Learn about the diversity of lake ecosystems, explore their vital role in human development and planetary health, uncover the threats they face, and access tools and resources to join UNEP and partners in the mission to conserve, protect, and restore them to their former glory! 


Lakes for peace and sustainability

World Water Day is a call to action for transboundary cooperation to conserve and restore our lakes and other freshwater resources.


Sustainable Lake Management Course

Enroll now in the online course and learn how to ensure the long-term health and vitality of lakes worldwide

UN Decade Challenge

Conserving the Heart of the Congo Basin

Home to unique freshwater lakes within the peatlands, these interconnected water ecosystems are vital for our climate and water future

You can find lakes all over the world, usually freshwater, sometimes alkaline or salty, some of them spanning thousands of square kilometers, others no larger than a few football fields. They are cradles for diverse life forms and human civilizations, but have been badly affected by a combination of over abstraction, pollution and climate change. That's why Member States passed and are keen to see the United Nations Environment Assembly resolution on Sustainable Lake Management of March 2022 implemented as quickly and as fully as possible.

Protecting and restoring lakes and other freshwater ecosystems also form a key area of action for the UN Decade on Ecosystem Restoration, including the newly launched Freshwater Challenge

Across the world, lakes fed by rivers, glacial melt, groundwater, rain and snow have played an important role in human civilization, culture and development. They contain most of the liquid fresh water on the planet’s surface, house an array of wildlife, and make  farming, fishing and industry possible. They also play an important role in water storage, aquifer recharge and air temperature regulation. Yet, due to climate change, pollution, mining, population pressure, and unsustainable use, they are declining at an unprecedented rate. Freshwater ecosystems have lost more extent and biodiversity than almost any ecosystem in the world.

The planet’s more than 3 million lakes vary enormously in terms of their salinity and chemical composition, area, depth, biodiversity, the volume of water they store, their ownership (whether publicly or privately owned), the extent to which they are polluted, the rate at which they are shrinking, and more. Lake Baikal in Russia is estimated to contain 20 % of the planet’s liquid freshwater resources – about the same as all the North American Great Lakes combined. The largest lake in terms of area is the Caspian Sea, which has varying levels of salinity. Lake Natron in Tanzania is one of the most alkaline lakes in the world. Utah’s shrinking Great Salt Lake is releasing toxic dust from exposed lake beds. Lake Van in eastern Turkey is an example of an endorheic lake – it has no natural outlet.

The threats facing lakes are interlinked. Lake pollution is frequently caused by inflows from nutrients , surface-bound contaminants and solid waste being dumped directly or flushed into lakes via rivers, and this is worsened by global heating – leading, for instance, to more frequent and intense floods. UNEP’s 2021 flagship report Making Peace With Nature notes that “water pollution has continued to worsen over the last two decades, increasing the threats to freshwater ecosystems and human health.”

Fertilizer is an important component of modern food systems, and yet it is also a major source of river and lake pollution through nitrogen and phosphorus accumulation. Rain washes the nutrients in fertilizer into waterways and lakes which can lead to damaging algal blooms, which are predicted to increase by at least 20% by 2050 and are already a serious challenge and intensifying in global freshwater lakes.

Wastewater is another pollution threat. Billions of people are still lacking safely managed sanitation, and up to 80 % of global wastewater is estimated to enter water bodies untreated with adverse impacts on human and ecosystem health.

The water levels of lakes are also changing dramatically. Rising temperatures and changes to cloud cover, which are leading to decreasing ice cover,  are increasing the rate of water evaporation. A new global study covering a staggering 1.42 million lakes suggests evaporation is causing them to shrink faster than previously thought. Climate change is also causing glacier melt which can lead to the threat of glacial lake outbursts that can devastate downstream communities.

Recognizing these threats, in March 2022 the United Nations Environment Assembly adopted a resolution on Sustainable Lake Management. It calls on countries to protect, restore, and sustainably use lakes, while integrating them into national and regional development plans. It does not distinguish between freshwater, alkaline, saltwater or soda lakes.

The same Assembly adopted a resolution on sustainable nitrogen management, which encourages Member States to accelerate actions to significantly reduce nitrogen waste globally by 2030 and beyond through the improvement of sustainable nitrogen management.

The Assembly also passed a resolution on nature-based solutions for sustainable development, which can promote the protection, conservation and restoration of healthy lakes to help combat the triple planetary crisis of biodiversity loss, climate change and pollution.

Tackling interlinked threats requires sustainable lake management involving the collaboration of stakeholders (such as rice farmers dependent on lake water) to ensure sustainable land management and integrated water resources management.



Find out about upcoming lakes conferences, workshops and learning sessions.


Read the latest international media reports, lake stories from the UN Environment Programme, videos, and podcasts.


Click here to explore videos, connect with the lakes, and deepen your understanding.


Find data and information about lakes and further freshwater ecosystems.


Multilateral agreements set out a path for action to protect, conserve and restore lake ecosystems. See the most relevant ones here.


Deep dive investigations into individual lake ecosystems highlight the need for context-specific restoration interventions.


The listed resources can help us understand the impact of this environmental problem.


New and innovative partnerships can accelerate urgently needed action. Discover the network!