Without water, we can only survive for a few days. Pollution and over abstraction have threatened important drinking water sources.
Healthy freshwater ecosystems (water catchments, wetlands, forests) naturally clean the pollution and toxins from water.
Soils, micro-organisms, and plant roots all help in filtering out pollutants and they do this for free, reducing the costs of water filtration or treatment plants.
Research shows that the more biodiverse the ecosystems the faster and more efficiently water is purified.