Hareshaw Linn: minimising potential energy

Hareshaw Linn is a waterfall in an impressively gothic ravine near Bellingham in Northumberland. This picture doesn't really do it justice. Solar energy lifted the water up from the sea by evaporation, doing work against gravity and giving it a lot of gravitational potential energy. Then the water begins to try to minimise its potential energy. It always seeks out the lowest point. This waterfall is an impressive example of it doing that. Yet even on the waterfall itself, there were certain channels that must have lower potential energy than other parts as the water sticks to certain routes across the fall.