The Sinking Island

An island's residents pumped groundwater for their wells.

The pumping caused the land to sink, slowly. As the land sank, seawater crept into the wells.

Salty water was undrinkable. So they pumped deeper.

Deeper pumping caused faster sinking. Faster sinking brought more seawater. More seawater required even deeper wells.

A visitor asked why they didn't stop pumping.

"We need water today," they said.