Executive summary

Freshwater mobilizes and amplifies the risks to human health and the environment associated with human activities (established but incomplete). The global water cycle integrates the impacts of population growth, agriculture, economic development, urbanization, industrialization, deforestation and climate change. All of these impacts affect freshwater quality and quantity. Hence, freshwater is now simultaneously a public good and a risk multiplier, affecting human and ecosystem health through pollutants and through climate change, which is intensifying storms, floods, droughts and desertification of land. Improved governance of every aspect of the water cycle is urgently needed in order to prevent, mitigate and manage these increasing risks.  9.2 ▸ 

The per capita availability of freshwater in the global water cycle is decreasing with population growth, coupled with the associated agricultural, industrial and energy requirements (established but incomplete), while the continents are becoming drier in many places due to climate change impacts.  9.2 ▸ 

Increasing numbers of people are at risk of ‘slow-onset disasters’ such as water scarcity, droughts and famine. Such events sometimes lead to increased migration and social conflicts (well established) {4.2}. The rising severity and frequency of water-related disasters pose growing risks to social and economic stability, as well as to ecosystems and their life-supporting ecosystem goods and services. There is evidence that water scarcity drives greater competition for available resources, reflected in food insecurity, prices and trade (established but incomplete).  9.2 ▸ 

Groundwater comprises a much larger freshwater volume than surface water. It is increasingly important for water security in many countries and regions (established but incomplete). Some major aquifers at subregional and regional levels are threatened by poor management, resulting in unsustainable abstraction levels, groundwater pollution and issues of saline intrusion.  9.4.1 ▸ 

Approximately 1.4 million people die annually from diseases associated with pathogen-polluted drinking water and inadequate sanitation, with many millions more becoming ill (well established). Some 2.3 billion people still do not have access to safe sanitation. The total global disease burden could be cut by up to an estimated 10 per cent with improved drinking water quality and access, sanitation, hygiene and integrated water resources management.  9.5 ▸ 

Human illnesses and deaths due to antibiotic- and antimicrobial-resistant infections are increasing rapidly and are projected to become a main cause of death worldwide by 2050 (well established). Antibiotics reach the aquatic environment from a wide range of sources, including treated and untreated human waste, agriculture, animal husbandry and aquaculture. Antibiotic-resistant bacteria are now found in both source water and treated drinking water worldwide.  9.5 ▸ 

New pollutants not easily removed by current wastewater treatment technologies are of emerging concern, including certain veterinary and human pharmaceuticals, pesticides, antimicrobial disinfectants, flame retardants, detergent metabolites and microplastics (well established). Endocrinedisrupting chemicals are of particular concern as they are now widely distributed through the freshwater system on all continents. Their long-term impacts on human health include fetal underdevelopment, child neurodevelopment and male infertility.  9.7.1 ▸ 

Freshwater ecosystems are disappearing rapidly, representing a high rate of loss of biodiversity and ecosystem services (well-established). Wetlands are the natural areas most affected by increasing urbanization, agricultural expansion and deforestation. Approximately 40 per cent of the world’s wetlands were lost between 1997 and 2011, and this rate of loss continues. This is linked to an 81 per cent freshwater species population decline over the same period, the highest for any type of habitat (likely). The annual economic cost of wetland ecosystem losses between 1996 and 2011 was estimated at US$2.7 trillion.  9.6.1 ▸ 

Peatlands (one type of wetland) store more carbon than all the world’s forests combined (established but incomplete). Climate change is thawing permafrost in boreal peatlands in and around the Arctic Circle, causing increased carbon emissions. Increased drainage and agricultural use of tropical peatlands cause wildfires and release significant quantities of carbon dioxide and methane as greenhouse gases. Altogether, about 15 per cent of peatlands worldwide had been drained by 2015, and currently contribute approximately 5 per cent of annual global carbon emissions.  9.6.1 ▸ 

SDG 6 water targets can be realized through engaging the public, private and non-governmental sectors, civil society and local actors in practising effective, efficient and transparent water resources governance (well established).  9.9 ▸ 

Promoting water-use efficiency, water recycling and rainwater harvesting is becoming increasingly important to ensure greater water security and more equitable water allocation for different users and uses (well established).  9.9 ▸ 

The agricultural sector, the largest consumer of freshwater globally, needs substantial improvements in water-use efficiency and productivity (well established). The industrial and mining sectors also have strong potential for increasing water-use efficiency, recycling and reuse, as well as limiting water pollution.  9.9 ▸ 

Limited capacity currently exists to control long-term impacts of aquifer overabstraction and pollution in many locations (established but incomplete). Monitoring, modelling and managing aquifer systems are essential to implement sound aquifer and integrated water resources management. Salinization of aquifers resulting from subsidence in river deltas is a complex catchment and coastal urbanization issue (SDG 11), but saline intrusion into coastal aquifers can be controlled by managed aquifer recharge (well established).  9.9 ▸ 

Efficient water use requires water-sensitive urban design of water infrastructure, including conjunctive surface and groundwater development and the promotion of managed aquifer recharge (well established). Together with investment in wastewater treatment and recycling, these approaches support water quantity and quality management, and promote drought risk reduction and resilient urban water supplies. At the same time, the provision of drinking water supply and sanitation services to all, as well as leakage control from bulk water supplies, are still challenges in many cities worldwide.  9.9 ▸