Groundwater could be vital to sustaining clean water supplies, new research shows.

Almost 60% of the world’s yearly rainfall ends up as groundwater, yet most drinking and irrigation water comes from above-ground rainwater supplies. Groundwater is naturally cleaned and filtered through soil extraction of excess heavy metals and impurities, and could be used to help stretch water supplies in drought-affected areas.

However, clean groundwater supplies are currently threatened by poor land management policies which can lead to flooding and contamination of clean water supplies.