Water plays a central role in climate adaptation, as it is one of the sectors most affected by climate change, but also one that offers many entry points for adaptation. Given its close links to sectors such as food, energy, health and ecosystems, strengthening water resilience also supports climate adaptation across these interconnected sectors. Water is thus at the heart of climate adaptation, influencing ecosystems, agriculture and food security, urban planning, and human livelihoods.

Climate change is fundamentally altering the global water cycle, leading to more frequent and intense droughts, floods and other water-related hazards. At the same time, long-term changes such as glacier retreat, groundwater depletion and the degradation of rivers and wetlands are reducing the amount of water that is available to both people and ecosystems (Madani, 2026). Climate change therefore also directly influences water and sanitation supplies, which has far-reaching consequences for water security, agriculture, ecosystems, infrastructure and numerous sectors of the economy. 

Water-related disasters already account for over 74% (2001–2018) of all natural disasters worldwide (WMO) and have affected around 3 billion people since 2000, (1.65 billion due to floods and 1.43 billion due to droughts). Since 2000, the frequency of floods has increased by 134% and that of droughts by 29% (UNDRR, 2025). These developments highlight the close links between climate adaptation and disaster risk reduction (DRR). As these water-related hazards become more frequent and severe, strengthening water resilience is increasingly recognized as a key strategy for reducing disaster risks before they materialize. This includes measures such as climate-resilient water infrastructure, integrated water resources management, improved water storage, early warning systems and nature-based solutions, all of which help reduce vulnerability while increasing preparedness for future climate extremes. 

Strengthening water resilience through climate adaptation measures can therefore help societies to better prepare for and respond to climate-related risks while also contributing to climate change mitigation by offering considerable emissions reduction pathways. In this regard, the water and wastewater sector offers significant potential, as it accounts for 7 % of global greenhouse gas emissions. Wastewater systems alone account for 2–6 per % of methane emissions and 1–3 per % of nitrous oxide emissions. Improved wastewater treatment, efficient water supply systems and nature-based solutions (e.g. wetland restoration), as well as resource recovery and circular approaches can reduce emissions significantly and deliver social, environmental and economic benefits.

As water is fundamentally linked to other sectors, climate impacts on water resources have far-reaching consequences across society. The agricultural sector for example is the world’s largest water consumer, drawing 72% of its used freshwater from surface and groundwater sources (FAO, 2021). Global food security is therefore heavily dependent on stable and predictable water availability. Water and health are also closely interlinked, as safe drinking water, adequate sanitation and good hygiene are crucial for preventing disease, protecting public health and ensuring a functioning health system. 

In terms of biodiversity, healthy rivers, wetlands, glaciers, soils and aquifers are the foundation of resilient water systems. They regulate water flows, improve water quality and reduce the impacts of floods and droughts. However, these natural water stores are increasingly under pressure. It is estimated that the world has lost around 410 million hectares of natural wetlands over the past five decades, while more than half of the world’s large lakes have been shrinking since the early 1990s (Madani, 2026). Protecting and restoring these ecosystems is therefore a key element of water-focused climate adaptation and helps strengthen ecosystem resilience. 

However, despite its important role in climate adaptation, water continues to receive insufficient political attention and investments compared to its importance for climate resilience. Water-related adaptation measures remain underrepresented in many national climate policies and adaptation plans, as well as in National Determined Contributions (NDCs) and financing falls short of estimated needs. 

The importance of water in climate adaptation is reflected in several major global frameworks, including the 2030 Agenda for Sustainable Development, the Paris Agreement under the United Nations Framework Convention on Climate Change (UNFCCC) and the Sendai Framework for Disaster Risk Reduction (UNDRR). The Paris Agreement calls for the adaptation of WASH infrastructure to climate change and encourages countries to incorporate water-related adaptation into their NDCs and NAPs while the Kunming–Montreal Global Biodiversity Framework (GBF) recognizes the protection and restoration of freshwater ecosystems as an important contribution to climate resilience. Additionally, the key role of water for climate adaptation and resilience, has been anchored in the UNFCCC Conference of Parties 27 (COP27) Sharm El-Sheikh declaration for the first time. At COP30, 59 indicators for the Global Goal on Adaptation (GGA) were adopted, including 9 water indicators with many cross-references to SDG 6 indicators.

In addition to global frameworks, the importance of the linkage between water and climate adaptation is also reflected in several international initiatives, including the Water for Climate Pavilion, coordinated by the Stockholm International Water Institute (SIWI), which has become an important platform for advancing the water–climate adaptation agenda within the UNFCCC process. It brings together more than 90 partners from governments, international organizations, NGOs and the private sector, with the main objective to raise awareness of the role of water in climate action, showcase water-related adaptation solutions, and support countries in strengthening the water dimension of their NDCs and NAPs (SIWI). Likewise, the Baku Dialogue on Water for Climate Action, which was launched at the COP29 by the Presidency of Azerbaidjan, brings together 73 states and many stakeholders and aims to foster continuity and coherence on water-related climate action within the UNFCCC process. 

Other initiatives, such as the Alliance for Global Water Adaptation (AGWA), support countries in integrating water into climate planning and implementation through technical and policy-oriented programs.

The 2026 UN Water Conference will provide another important opportunity to advance the global water and climate agenda. To facilitate discussions, the Conference is structured around six Interactive Dialogue Themes, including Interactive Dialogue C: Water for Planetm, co-chaired by Egypt and Japan, which focuses on matters centered around protecting and restoring freshwater ecosystems and strengthening resilience to climate change and Interactive Dialogue E: Water in Multilateral Processes, co-chaired by Germany and Mexico which focuses on strengthening water governance and its interlinkages with other international processes including on climate change. Within this framework, it is expected that particular attention will be given to ecosystem-based approaches, nature-based solutions, and integrated water management as key enablers of climate adaptation. Furthermore, Interactive Dialogue E will give critical input on how to anchor water more systematically and synergistically in the Rio Conventions, leveraging the potential of water to advance their respective objectives, including those related to climate adaptation.

Water climate adaptation depends on action across multiple governance levels, including international policy processes, national planning and local implementation. At the national level, the main entry points for action lie with integrating water related measures into National Adaptation Plans (NAPs) which outline a country’s medium- to long-term strategies for adapting to climate change, on a sector basis. This, however, should be accompanied by an enabling policy environment, adequate financing and strong and capable institutions that can support coordinated implementation across sectors and governance levels. Climate-resilient water governance also requires reliable data, monitoring systems and stakeholder participation to support evidence-based decision-making. 

At the local level, adaptation strategies need to be translated into context-specific measures that address the various and unique challenges on the ground. In this process, it is therefore crucial, to enhance capacity development, establish inclusive governance processes and ensure the involvement of local communities, especially indigenous people, women and marginalized groups, to develop holistic local approaches. 

Water-focused climate adaptation is implemented through a range of complementary approaches that combine policy and institutional reforms and practical measures on the ground. The specific intervention depends on the local context but many approaches share common principles including integrated planning, cross-sectoral cooperation, ecosystem protection and capacity development. The below listed approaches serve as a collection of the most commonly implemented strategies in different sectors: 

• Urban water resilience

Today, ca 50% of the world’s population resides in cities, and approximately two-thirds of global population growth until 2050 is expected to concentrate in urban areas.  In this context, biodiversity loss and the impacts of climate change pose major challenges for sustainable water and wastewater management in cities and their catchment areas (UN-Habitat, 2025). Between 30–50 %of the global urban population will be affected by water scarcity by 2050, whilst urban water demand is set to rise by around 80% by 2050 (WBGU, 2024). In addition, more frequent extreme weather events due to climate change are expected to have serious impacts on human safety, infrastructure and health in cities.

It is therefore crucial to prepare cities for these upcoming challenges by implementing urban water resilience strategies.  One of the key approaches for this is the implementation of Integrated Water Resources Management (IWRM), particularly to ensure sufficient water quantity and quality for various uses (e.g. households, industry, urban agriculture). Other specific measures to promote urban water resilience include: 

• Participatory governance processes, including raising awareness of water risks
•  Strengthening capacities and cooperation between the public and private sectors (e.g. water operators, waste management companies, industry)
• Rainwater management in line with the ‘sponge city’ concept
• Reuse of treated wastewater, e.g. for groundwater recharge
• Nature-based solutions (river restoration, multifunctional green spaces, green roofs) and hybrid (grey-green-blue) infrastructure
• Climate-resilient sanitation and hygiene systems
• Disaster risk management, including early warning systems

• Climate-smart agriculture (incl. e.g. Climate resilient irrigation)

Water is central to agricultural production and food systems. The availability and efficient use of water in agriculture are therefore essential for ending hunger (SDG 2) and achieving many other related SDGs. Climate change poses a threat to water availability and calls for more resilient and lower-emission agricultural production systems. At the same time, agriculture accounts for 70 % of global water withdrawals (GIZ, 2023), which underlines the importance of cross-sectoral approaches between the water and agriculture sectors. The Climate-Smart Agriculture (CSA) approach addresses these challenges by promoting agricultural systems that strengthen food security and resilience while also contributing to climate change mitigation. 

This includes measures such as modernizing irrigation systems, improving soil moisture management, increasing water storage and promoting integrated water resources management. Effective irrigation is particularly important, as only around 23% of global cropland is equipped for irrigation, yet these areas produce approximately 48% of global crop value and achieve yields that are, on average, 76% higher than rainfed yields (FOA, 2026). At the same time, more than 60% of irrigated land is already located in areas experiencing high or very high water stress, highlighting the need to improve irrigation efficiency and climate resilience. One example for improved irrigation management is the Solar-powered irrigation system (SPIS) which provides a clean, affordable and climate-friendly alternative for water lifting and distribution, while also enhancing rural electrification and contributing to reduced GHG emissions.

• Water Reuse

Sustainable and efficient water use and wastewater treatment are crucial to reducing the growing pressure on global water resources. Water reuse offers an opportunity to increase water availability by making optimal use of the value of (waste)water as a service, energy source, raw material and nutrient carrier. Decentralised water reuse has the potential to increase from the current level of around 12 % to around 50 % by 2040 (World Bank, 2025). Depending on local conditions, treated wastewater can be reused in agriculture, industry, groundwater recharge or even drinking water supply. Besides increasing water security, water reuse also supports circular economy approaches by recycling water, nutrients and energy from wastewater while reducing pollution and improving resource efficiency.

• Climate Adaptation within Integrated and Transboundary Water Resources Management (IWRM/TWRM)

Integrated Water Resources Management (IWRM) is one of the most widely applied approaches for water-focused climate adaptation. It promotes the coordinated development and management of water, land and related resources to maximize social and economic benefits while maintaining healthy ecosystems. By considering water quantity, water quality, ecosystem needs and competing water uses together, IWRM helps countries strengthen water security and improve resilience to climate change.

Many of the world’s major rivers, lakes and aquifers are shared by two or more countries, making transboundary cooperation an essential component of climate adaptation. Climate change is expected to increase variability in water availability and intensify competition over shared water resources, requiring stronger cooperation between riparian states. Transboundary Water Resources Management (TWRM) therefore builds on the principles of IWRM by promoting joint planning, information sharing, coordinated monitoring and the cooperative management of shared water resources across national borders. In addition to the direct impact in climate adaptation, this approach can also lead to various positive outcomes like an improved dialogue between riparian states and authorities, joint planning that considers the entire basin and doesn’t stop at local borders and can even result in more stability and peace in the region. 

Typical measures implemented under IWRM and TWRM include:

• integrated river basin and catchment management; 
• basin-wide ecosystem restoration and other nature-based solutions, such as wetland restoration and floodplain rehabilitation; 
• joint flood and drought risk management, including early warning systems; 
• coordinated monitoring and data sharing on water quantity, quality and climate risks; 
• environmental flow management to maintain healthy freshwater ecosystems; and 
• institutional cooperation through river basin organisations, joint adaptation planning and shared governance mechanisms. 

• Nature-based Solutions

Nature-based solutions (NbS) are an overarching concept for various ecosystem-based approaches, such as ecosystem-based adaptation (EbA), ecosystem-based disaster risk reduction (Eco-DRR) and ecosystem-based mitigation (EbM). NbS are a key element of integrated water resources management (IWRM) and support the protection, sustainable use and restoration of (freshwater) ecosystems. Intact ecosystems ensure water quality, climate-resilient water security, and the protection and connectivity of aquatic habitats and biodiversity. In addition to strengthening climate resilience, nature-based solutions often provide multiple co-benefits, including biodiversity conservation, improved water quality, carbon sequestration and enhanced livelihoods. 

Common nature-based solutions in water-climate adaptation include measures such as the restoration of wetlands, rivers and floodplains to improve water storage and reduce flood risks, catchment and watershed restoration to enhance groundwater recharge and reduce erosion, and the protection of forests and upstream ecosystems to regulate water flows and improve water quality. In urban areas, green infrastructure such as green roofs, urban wetlands and rain gardens can help manage stormwater, reduce flood risks and mitigate urban heat. Along coastlines, the restoration of mangroves and other coastal ecosystems can reduce erosion and simultaneously protect communities from storm surges while supporting biodiversity and local livelihoods. 

Most nature-based solutions aim to restore or enhance the natural functions of ecosystems, allowing them to regain their buffering capacity and continue providing essential ecosystem services such as water storage, flood regulation and water purification. At the same time, they typically address multiple challenges simultaneously by integrating climate adaptation with biodiversity conservation, disaster risk reduction and sustainable water management