The Amakawa River is said to flow with over 400 tons of water in one day. This river has never run dry, not once.

How is it that water springs up from an isolated island? The island itself was created as the result of an eruption; the ground consists of sponge-like rock with plenty of holes for water to spring up from the ground. Water flows in from the rains and a layer of freshwater forms over the hard layer of saltwater underneath the ground. The freshwater then bubbles up from the pressure of the saltwater, gushing up to the surface all over the island.

Not only has this water become an important water source for the people of the island, but it is also an essential resource for their rice harvests as well.