Optimal boundary conditions, determining the possibility of safe development of deposits under water bodies, is determined, first of all, by the safe depth of work, With some approximation for this mark in the excavation of deposits can be taken as the limit value of the height of the zone of development of fracturing, remembering, however, that the latter largely depends on the dialogic structure of rocks and roof management method ...

In the practice of field development under reservoirs and large aquifers very difficult in theoretical and practical terms is the choice of a safe depth for mining operations. This explains, on the one hand, the frequent abandonment of large reserves of minerals in pillars, and on the other hand - water breakthroughs, causing disruption of work and accidents.In Donbass, Kuzbass, Moscow region and other basins accumulated considerable experience of mining coal seams under water bodies.

One of the most difficult tasks in mining is the development of deposits under water bodies and large aquifers. Mining operations under water bodies are insufficiently studied. As a result, in some cases a lot of coal is lost in safety and barrier pillars, and in other cases improper mining leads to water breakthroughs causing disruption of operations and accidents with people. For example, the U.S. Bureau of Mines cites seven cases of catastrophic flooding of mines in Pennsylvania, mostly as a result of improper mining of barrier pillars. At the same time, according to the data of this bureau, according to the data of this bureau, with the correct choice of the mining system, methods of pillar mining and roof management it was possible to recover up to 35% of the reserves lost in the barrier pillars, i.e. 250 mln. m of anthracite. It would allow to prolong the work of mines for 5 years.