Flood-tide: rising tide, part of the tidal cycle between low water and the next high water.

UNESCO: L O S S A R Y

Ebb-tide: the falling tide, part of the tidal cycle between high water and the next low water.

UNESCO: L O S S A R Y

The tidal cycle powering the barrage might not coincide with demand for electricity.

BBC: Barrage 'fixation' claims group