Here's why:
* Ice and Glaciers: The vast majority of freshwater is locked up in ice caps and glaciers (about 69% of the world's freshwater). This water is not easily accessible for human use.
* Groundwater: Another large portion of freshwater is found underground as groundwater (about 30% of the world's freshwater). While some groundwater is accessible through wells, much of it is too deep or polluted to be easily used.
* Surface Water: The remaining freshwater is in lakes, rivers, and swamps (about 1% of the world's freshwater). This is the water we most commonly use, but even this is limited by factors like evaporation, seasonal changes, and pollution.
In summary: While freshwater is abundant on Earth, only a small fraction of it is readily available for human use. This limited availability makes water conservation and sustainable management crucial.