This contribution describes the analysis of data collected during monitoring of mining backwater level in Jeronym Mine in Čistá. Several flooded areas is possible to find in this medieval mine, of which five are quarterly or continuously monitored. Water in mining workings comes from precipitation mainly (snow, rainstorm), adit floor is connected with the groundwater in the vicinity of the mine. The nature of the individual flooded areas is described in detail in the paper, and the results of the measurement of mining water levels for the period 2001-2012 are presented. The maxima of individual monitored backwater levels are determined by overflows to the below located workings. In the article, rate of decrease and increase in level at the V2/KV2, V3/KV3 and V5/KV5 places are processed in detail.