Below is a link to an excellent information page by UN Water Facts. Their introductory text on water is crystal clear [abbreviated citation]:
“Water is at the core of sustainable development and is critical for socio-economic development, healthy ecosystems, and for human survival itself.
Water is also at the heart of adaptation to climate change, serving as the crucial link between the climate system, human society, and the environment.
The physical world of water is closely bound up with the socio-political world, with water often a key factor in managing risks such as famine, epidemics, inequalities, and political instability”.