The United Nations World Water Assessment Programme (WWAP) is hosted and led by UNESCO. WWAP brings together the work of 31 UN-Water Members as well as 37 Partners to publish the United Nations World Water Development Report (WWDR) series. Under the theme Water for Sustainable Development, the WWDR 2015 has been prepared as a contribution from UN-Water to the discussions surrounding the post-2015 framework for global sustainable development. Highlighting water's unique and often complex role in achieving various sustainable development objectives, the WWDR 2015 is addressed to policy- and decision-makers inside and outside the water community, as well as to anyone with an interest in freshwater and its many life-giving benefits. The report sets an aspirational yet achievable vision for the future of water towards 2050 by describing how water supports healthy and prosperous human communities, maintains well functioning ecosystems and ecological services, and provides a cornerstone for short and long-term economic development. It provides an overview of the challenges, issues and trends in terms of water resources, their use and water-related services like water supply and sanitation. The report also offers, in a rigorous yet accessible manner, guidance about how to address these challenges and to seize the opportunities that sound water management provides in order to achieve and maintain economic, social and environmental sustainability.

Access to water and sanitation is internationally recognized human right. Yet more than t wo billion people lack even the most basic of services. The latest United Nations World Water Development Report, Leaving No One Behind, explores the symptoms of exclusion and investigates ways to overcome inequalities.

The 2020 edition of the WWDR, titled Water and Climate Change illustrates the critical linkages between water and climate change in the context of the broader sustainable development agenda. Supported by examples from across the world, it describes both the challenges and opportunities created by climate change, and provides potential responses – in terms of adaptation, mitigation and improved resilience – that can be undertaken by enhancing water resources management, attenuating water-related risks, and improving access to water supply and sanitation services for all in a sustainable manner. It addresses the interrelations between water, people, environment and economics in a changing climate, demonstrating how climate change can be a positive catalyst for improved water management, governance and financing to achieve a sustainable and prosperous world for all. The report provides a fact-based, water-focused contribution to the knowledge base on climate change. It is complementary to existing scientific assessments and designed to support international political frameworks, with the goals of helping the water community tackle the challenges of climate change, and informing the climate change community about the opportunities that improved water management offers in terms of adaptation and mitigation.

Water has always been a source of risks and opportunities in the Middle East and North Africa. Yet rapidly changing socioeconomic, political, and environmental conditions make water security a different, and more urgent, challenge than ever before. This report shows that achieving water security means much more than coping with water scarcity. It means managing water resources in a sustainable, efficient, and equitable way. It also involves delivering water services reliably and affordably, to reinforce relationships between service providers and water users and contribute to a renewed social contract. Water security also entails mitigating water-related risks such as floods and droughts. Water security is an urgent target, but it is also a target within reach. A host of potential solutions to the region’s water management challenges exist. To make these solutions work, clear incentives are needed to change the way water is managed, conserved, and allocated. To make these solutions work, countries in the region will also need to better engage water users, civil society, and youth. The failure of policies to address water challenges can have severe impacts on people’s well-being and political stability. The strategic question for the region is whether countries will act with foresight and resolve to strengthen water security, or whether they will wait to react to the inevitable disruptions of water crises.

This flagship report is a comprehensive review that gives an overall picture of the world's freshwater resources. It analyses pressures from decisions that drive demand for water and affect its availability. It offers tools and response options to help leaders in government, the private sector and civil society address current and future challenges. It suggests ways in which institutions can be reformed and their behaviour modified, and explores possible sources of financing for the urgently needed investment in water. The WWDR4 is a milestone within the WWDR series, reporting directly on regions and highlighting hotspots, and it has been mainstreamed for gender equality. It introduces a thematic approach - 'Managing Water under Uncertainty and Risk' - in the context of a world which is changing faster than ever in often unforeseeable ways, with increasing uncertainties and risks. It highlights that historical experience will no longer be sufficient to approximate the relationship between the quantities of available water and shifting future demands. Like the earlier editions, the WWDR4 also contains country-level case studies describing the progress made in meeting water-related objectives. The WWDR4 also seeks to show that water has a central role in all aspects of economic development and social welfare, and that concerted action via a collective approach of the water-using sectors is needed to ensure water's many benefits are maximized and shared equitably and that water-related development goals are achieved.

To sustain Africa’s growth, and accelerate the eradication of extreme poverty, investment in infrastructure is fundamental. In 2010, the Africa Infrastructure Country Diagnostic found that to enable Africa to fill its infrastructure gap, some US$ 93 billion per year for the next decade will need to be invested. The Program for Infrastructure Development in Africa (PIDA), endorsed in 2012 by the continent’s Heads of State and Government, lays out an ambitious long-term plan for closing Africa’s infrastructure including trough step increases in hydroelectric power generation and water storage capacity. Much of this investment will support the construction of long-lived infrastructure (e.g. dams, power stations, irrigation canals), which may be vulnerable to changes in climatic patterns, the direction and magnitude of which remain significantly uncertain. Enhancing the Climate Resilience of Africa 's Infrastructure evaluates -using for the first time a single consistent methodology and the state-of-the-arte climate scenarios-, the impacts of climate change on hydro-power and irrigation expansion plans in Africa’s main rivers basins (Niger, Senegal, Volta, Congo, Nile, Zambezi, Orange); and outlines an approach to reduce climate risks through suitable adjustments to the planning and design process. The book finds that failure to integrate climate change in the planning and design of power and water infrastructure could entail, in scenarios of drying climate conditions, losses of hydropower revenues between 5% and 60% (depending on the basin); and increases in consumer expenditure for energy up to 3 times the corresponding baseline values. In in wet climate scenarios, business-as-usual infrastructure development could lead to foregone revenues in the range of 15% to 130% of the baseline, to the extent that the larger volume of precipitation is not used to expand the production of hydropower. Despite the large uncertainty on whether drier or wetter conditions will prevail in the future in Africa, the book finds that by modifying existing investment plans to explicitly handle the risk of large climate swings, can cut in half or more the cost that would accrue by building infrastructure on the basis of the climate of the past.