Water covers more than 66% of the surface of Earth. Nearly all of Earth's water is found in seas and other saltwater bodies. However, only about 2.5% of Earth's water is freshwater, with almost 68.7% of it trapped in glaciers and ice caps, making it unavailable for immediate human consumption. Most of the remaining freshwater is solidified in the form of snow cover, contributing significantly to the planet's water resources.

Waterways, lakes, wetlands, and aquifers that contain easily accessible freshwater represent less than 1% of the world's water supply. However, despite this seemingly small percentage, these sources sustain a vast array of ecosystems and contribute significantly to global biodiversity. Moreover, freshwater is indispensable for various human activities, ranging from agriculture and industry to drinking water supply and sanitation infrastructure, highlighting its critical importance for sustaining human livelihoods and well-being. But this valuable resource supports an enormous diversity of life and is vital for human survival.

The demand for water for a variety of different uses such as drinking, sanitation, farming, and energy production continues to increase as the worldwide population grows. In the meantime, human activities and environmental change are influencing changes in water cycles, putting freshwater ecosystems under strain. Pollution, construction and mining activities pose additional challenges.