In the Ropazu district at Latvia, a set of dolomite excavation quarries is located. Because the quarries must by drained by pumping out groundwater, depression cones appear in the quarry areas and around them. The research targets were investigation of the interaction between the quarries, evaluation of adverse changes caused by them in the groundwater regimes of the nature reserve wetland area «Lielie Kangari» and in flows of hydrographical network. The research was carried out by applying the hydrogeological model (HM) that was run by the system Groundwater Vistas 6. The quarries were simulated by using their toughest working conditions (maximal areas and depths for a long time excavation without interruptions). It was found out that due to appearance of artificial lakes in flooded areas of abandoned quarries, the interaction between the working quarries has considerably decreased. The quarries which are situated near the reserved wetland area and a small river can worsen their natural regimes. The methodology and results reported in the paper may be useful for specialists dealing with estimation of adverse effects that can be caused by mineral excavation quarries.