Tide Mill

A tide mill is a water mill driven by the rise and fall of the tide rather than by a river continuous flow. A dam fitted with a sluice gate is built across a suitable tidal inlet, or a section of a river estuary is enclosed as a reservoir, and as the tide rises it flows into the mill pond through a one-way gate that closes automatically once the tide begins to fall. Once the tide outside has dropped low enough, the water impounded in the pond is released to turn a water wheel, making the tide mill one of the oldest practical technologies for converting tidal energy into mechanical power.