The specific value of Kaluga Oblast's deposits is over RUR 8 million per m2.550 solid mineral deposits with 19 types of mineral resources, 131 fresh and 13 mineral subsoil water sources have been discovered in the oblast's territory.
12.
Similarly, the subsurface drainage requirement can be found from the drain discharge ( Dtr ) in the " subsoil water balance ", the " agronomic water balance ", the " geohydrologic water balance " and / or the " overall water balance ".
