Flooded mine

Without these systems the mine will get flooded by water that naturally occurs in rock formations in the ground.

The flooding process of an open-pit or underground mine can take from a several months period to more than a decade, depending on factors such as volume of open space in the mine, availability of infiltration water and on the nature of flooding - it can be uncontrolled, controlled or monitored.

The flooding process happens because the drainage wells or dewatering pumps are stopped and the open spaces are filled with groundwater and surface runoff from precipitation and water bodies (e.g. rivers).

[citation needed] Other important reason is safety: people coming to underground mines without safety precautions or the presence of dangerous mine gases.

Six of those main reasons are:[2] In some locations, there are discussions to use flooded mines for pumped-storage hydroelectric reservoirs,[3] but finished projects are still missing.