Accounting for approximately 99% of all liquid freshwater on Earth, groundwater has the potential to provide societies with tremendous social, economic and environmental benefits and opportunities. However, this natural resource is often poorly understood, and consequently undervalued, mismanaged and even abused. In spite of its overall abundance, groundwater remains vulnerable to over-exploitation and pollution, both of which can have devastating effects on the resource and its availability. In the context of growing water scarcity across many parts of the world, the enormous potential of groundwater and the need to manage it sustainably can no longer be overlooked. The 2022 edition of The United Nations World Water Development Report describes the challenges and opportunities associated with the development, management and governance of groundwater across the world.