SDG 6, however, goes far beyond water and sanitation services to cover the entire water cycle. Aside from domestic purposes, water is needed across all sectors of society, to produce food, energy, goods and services. These uses also generate wastewater which, if not properly managed, can spread diseases, and introduce excess nutrients and hazardous substances into rivers, lakes and oceans. Ultimately, as ecosystems provide water to society, a significant share of the water needs to stay within the ecosystems for them to remain healthy. Healthy ecosystems in turn safeguard the quantity and quality of freshwater, as well as overall resilience to human- and environmentally-induced changes.
The effects of climate change are often seen in changes in water availability, such as increasing water scarcity in some regions and flooding in others. Consequently, water is a key factor in managing risks related to famine, disease epidemics, migration, inequalities within and between countries, political instability and natural disasters. With limited water resources, it is important to fairly balance the water requirements of society, the economy and the environment. Also, most of the world’s water resources are shared between two or more countries. As such, the development and management of water resources has an impact across transboundary basins, making cooperation essential.