Scientists discover a massive underground “sponge” that can supply water to rivers and entire cities

As the world faces droughts and water shortages, the discovery of natural water systems is more important than ever. Now, scientists have uncovered a giant underground “sponge” capable of supplying water to rivers and entire cities.

This sponge isn’t artificial. It’s made of volcanic rock — the remnants of ancient lava flows — that act as a vast, porous water storage system. Rain and snowmelt seep in, and the water is gradually released into nearby ecosystems.

According to a report by Earth.com, this natural reservoir in the Cascade Mountains helps sustain river flow during dry periods and supports surrounding habitats without relying on man-made infrastructure.

How does the “sponge” work?

• Basalt rock from old lava flows is highly porous and absorbent.
• Water seeps in and stays underground for long periods of time.
• The sponge releases water slowly, feeding aquifers and springs.

This steady release maintains river flow, supports vegetation, and could supply entire cities — all without the need for dams or pumps.

Why it matters

• It offers a sustainable water solution in a warming world.
• Could reshape how cities approach long-term water management.
• Encourages preservation of volcanic landscapes as water reserves.

Nature has long held the answers to many of our challenges — we just need to listen, learn, and protect what we find.