Rivers and lakes are under increasing pressure globally from climate change, pollution and overuse. According to a 2026 report by the United Nations University, more than half of the world’s large lakes have lost water since the early 1990s, while roughly 410 million hectares of natural wetlands have disappeared over the past five decades. We sat down with Astrid Sotomayor, a Programme Management Officer with the United Nations Environment Programme (UNEP), to discuss how countries can better manage their freshwater catchments, and how improved practices would benefit both people and the environment.
With lakes and rivers facing a precipitous decline in many places, experts are touting the importance of catchment management. What exactly is that?
Astrid Sotomayor (AS): Catchment management seeks to protect and restore freshwater resources. It involves interventions within a defined area, such as a river basin, which would typically include springs, streams, smaller rivers, lakes and reservoirs. The aim is to implement plans, with buy-in from local interest groups, to improve the environment and people’s lives. By treating catchments as coherent hydrological units and integrating water, land use, agriculture, urban development and ecosystem conservation, we can reconnect fragmented freshwater systems and foster healthy, resilient ecosystems and communities.
How does this differ from integrated water resources management, another term that has become increasingly popular?
AS: Catchment management is usually a local-level intervention, though it can often span thousands of square kilometres. Integrated water resource management is a cross-sectoral process that coordinates the management of water, land and related resources at a catchment level as well as addressing water governance structures, laws and policies at the national level.
It has been said the key to managing catchments is managing what happens on land. Is that true?
AS: Yes. This is especially true for things like farms. For instance, if intensive fertilizer use is leading to run-off into local lakes and rivers and causing pollution or algal blooms, then people’s lives and livelihoods can be adversely affected. Soil degradation and water management are also deeply interconnected. Degraded soils are less able to absorb water, leading to reduced infiltration and higher flood risks. Eroded soil also contributes to sedimentation in rivers and lakes, which lowers water quality and disrupts aquatic ecosystems.
What are the challenges implementers of catchment management most frequently face?
AS: There are many. Catchment management is not just an engineering problem – for example removing or constructing dams – but also a governance challenge. It involves balancing competing water demands across sectors, strengthening stakeholder participation and responding to the impacts of climate change.
In the United States of America, for example, we have seen how the dwindling Colorado River and shrinking Lake Mead have led to governance challenges between states over water allocations.
One of the most common challenges is getting all stakeholders – including those at the national and local levels – to sit down together to agree on what resources to spend on which parts of a catchment.
What benefits would better catchment management mean to people around the world?”
AS: Better catchment management can significantly improve people’s lives by ensuring cleaner and more reliable water for households, agriculture and cities, while protecting rivers, lakes and surrounding ecosystems. It supports food security and livelihoods by improving agricultural productivity and water availability, particularly in water-stressed regions.
At the same time, healthy catchments help reduce the impacts of floods and droughts, strengthening communities’ resilience to climate change. When managed inclusively, they can also contribute to poverty reduction and more equitable decision making, delivering lasting environmental and social benefits.
As such, we must integrate addressing water resilience across policies that promote climate adaptation and mitigation, as well as land, ecosystem and biodiversity restoration actions and pollution ones. Such holistic approaches would ensure that improving water resilience is embedded across sectors at local and national levels and reflected on a global scale.
Is UNEP currently engaged in any catchment management projects?
AS: Yes. Activities such as intensive agriculture and mining jeopardize water security and ecosystem health. To tackle these challenges, Brazil’s Mato Grosso’s State Secretariat for the Environment, and Brazil’s National Water Agency, supported by UNEP and The Nature Conservancy Brazil, is strengthening catchment governance. The effort builds on existing local and national water policies and programmes. The initiative promotes integrated, evidence-based and participatory catchment management, including sustainable land and water management practices, and fosters multi-stakeholder cooperation to ensure long-term impact.
In India, the National Mission for Clean Ganga within the Ministry of Jal Shakti, supported by UNEP and WWF-India, is focusing on the conservation and restoration of the Kalewala wetland and the Dehla River. Its aim is to revive ecological functions, improve water quality through nature-based solutions, and strengthen community resilience through integrated, participatory and science-based planning that draws on both data and local knowledge.
These efforts are being funded by the European Commission to the tune of US$2 million and will run until August 2027. The project’s broader goal is to draw lessons from experiences in Brazil and India to develop a global framework of best practices for catchment management that can be adapted worldwide.
The theme for World Water Day on 22 March is “gender and water.” How does the project contribute to gender equality?
AS: The project places gender equality and diversity, as well as the knowledge and capacity of Indigenous Peoples and local communities, at the core of its approach, ensuring these principles are embedded in all activities. This includes strengthening inclusive water governance systems and promoting equitable participation in the design of integrated catchment management plans and water governance processes. By doing so, the project aims to empower marginalized groups, foster equitable decision-making and create long-lasting benefits for all stakeholders. Integrating gender-diverse and Indigenous expertise is essential l for equitable and effective water governance.
Can you provide any examples of UNEP projects where water management focuses on improving local conditions and people’s lives?
AS: Yes. UNEP and the UNEP-DHI Centre, in partnership with IUCN, with support from Denmark, has recently launched the Climate Resilient Eastern African Transboundary Water Management for Environmental Sustainability programme, which is a new initiative focused on strengthening climate-resilient and cooperative water management across Eastern Africa.
The programme is a multi-year initiative designed to support the governments of Kenya, Tanzania and Uganda to improve their transboundary water management to support water security, climate resilience, regional cooperation and sustainable development.
Initially, the programme will focus on two priority transboundary river basins: the Mara Basin, shared by Kenya and Tanzania, and the Sio-Malaba-Malakisi Basin, shared by Kenya and Uganda. Both of these basins face growing pressures from climate variability, rising water demand and inadequate transboundary governance agreements, while offering strong opportunities for cooperation and improved joint management.
