HYDROGEOLOGICAL ASPECTS OF INTENSIFICATION OF WATER EXTRACTION FOR THE CITY OF WROCŁAW IN THE MOKRY DWÓR REGION

Abstract

A new concept of water abstraction is to reduce the available surface of water-bearing areas only to the municipality of Wrocław. Under the new conditions it is necessary to intensify exploitation. To determine the impact of the new abstraction on the hydrogeological conditions a numerical model has been developed using Visual MODFLOW. The study covered the northern part of the water-bearing area of 6.68 km2. The total model balance was 28.3 k m3/d. To determine the optimum system performance and identify the sources of recharge, prognostic simulations (SYM I, SYM II, SYM III, SYM IV) were carried out. The forecasts rely on both ever more far-reaching expansion of the system, taking into account the wells operating under the previous (SYM I–SYM III), and the introduction of new sources of recharge in the form of ponds and horizontal drainages (SYM IV). The new barrier wells will increase the total yield of up to 25.9 k m3/d to 30.1 k m3/d. Only new ponds and horizontal drainage (65.3 k m3/d) allow meeting the desired discharge (61.0 k m3/d). As a result, we expect significant deformation of the direction of water flow and an increase in water quality risk.