Image: Lucy Chippindale
Sunlight reflects off a dark pool.
One of the limits for early miners was rising ground water, like this large pool, and until pumps were invented to drain this water, flooding was a real hazard. Adit mines tackled this problem by sloping upwards from the entry point, allowing the water to run out. Tunnels bored beneath the level of the drainage adit will inevitably flood, as will mines dug below the water table – unless, of course, the water can be pumped out using mechanical means or, as earlier in history, animal power.