Fresh water is vital to human life and wellbeing. Along with food and shelter, it forms our most basic need. So vital, in fact, that access to drinking water is commonly considered a fundamental right for all humanity. Healthy, functioning freshwater ecosystems provide reliable and quality water flows upon which these basic human needs depend. Energy, food and health – all indispensable to human development – rely on the water services provided by natural ecosystems. Freshwater ecosystems, such as wetlands and rivers, also provide crucial regulating services, such as water purification, flood mitigation and the treatment of human and industrial wastes. Now, more than ever, we must incorporate the value of water-related environmental services in our water management decisions. Eradicating poverty and hunger among the billions living in deprivation today and those in the future will depend fundamentally on water security – for both people and ecosystems.
Water is central to the functioning and resilience of the biosphere. Its availability and variability strongly influences the diversity and distribution of biomes and habitats that harbour the wealth of plant and animal life on Earth. Water of specific quantity and quality is required to preserve the state and stability of ecosystems and build their resilience to localised disturbance and to global change. It mediates the persistence of ecosystem types, their composition and function, and facilitates the migration of species and habitats as key environmental conditions such as temperature, rainfall, and soil moisture change.
Water’s central role in the biosphere has long implied that several of the most important challenges confronting human development are related to fresh water (e.g., Falkenmark, 1990). This has been true for decades and Healthy freshwater ecosystems: an imperative for human development and resilience will only intensify without a change in the course of human water use. For too long, conventional approaches to water planning have focused narrowly on economic productivity, largely ignoring the costs of overdrawing water from ecosystems or disrupting natural flow regimes with hard infrastructure. If we are serious about meeting human development objectives for the coming century, the way we plan and manage water resources must change.