Recharge of Gdańsk municipal groundwater intakes on the Vistula Delta Plain (Northern Poland)

Results of the Vistula Delta Plain Quaternary recharge analysis are presented in this paper. This region is situated south of Gdańsk city near the Bay of Gdańsk. There are two municipal intakes situated on the Vistula Delta Plain: Lipce and Grodza Kamienna. Different exploitation of the municipal intakes is considered. The numerical calculations are made for the pre- 1969 period before the Lipce intake started discharging the Quaternary aquifer in the steady-state conditions and for the 15 years period after the opening of the Lipce intake, in the transient conditions. The results of calculations of the natural state of the Vistula Delta Plain Quaternary aquifer are also presented. The numerical calculations were carried out using the Modflow and Modpath code in Groundwater Modelling System (GMS 2.1) package. Presented results of numerical calculations show that the Quaternary aquifer exploited by groundwater intakes Lipce and Grodza Kamienna is connected with inflow from the Martwa Wisła River into the Vistula Delta Plain Quaternary aquifer and confirm the Quaternary aquifer groundwater flow evaluation based on Cl– ions concentration in the observation wells.