what causes subsidence
The most common causes of subsidence are as follows: 1. Settlement of old mine workings, often at great depth, resulting in damage to structures on the surface. These may often be a long way from the cause of the damage. Access shafts are notoriously difficult to identify as mine operators rarely kept good records of these points. 2. Damage to subsoils caused by water flowing through them. This may be from naturally occurring ground water or leaking drains and water mains.