Water-filled quarries can be very deep, often 50 ft (15 m) or more, and surprisingly cold, so swimming in quarry lakes is generally not recommended.

Is it safe to swim in a rock quarry?

Quarries are extremely dangerous places to swim. Steep drop-offs, deep water, sharp rocks, flooded equipment, submerged wire, and industrial waste make swimming risky. ... Jumping or falling into cold water can be fatal - even for a young healthy person.

How do rock quarries fill with water?

So most quarries fill up naturally from groundwater seeping in and from rain once they're closed and the pumps are removed. As a side note these “sump holes” where the pump intakes where located are usually the deepest part of a quarry and an interesting area to explore.