Wody podziemne okolic Gdańska

Abstract

UNDERGROUND WATERS IN GDAŃSK REGION Summary In the Gdańsk region the underground waters are present in the Triassic, Cretaceous, Tertiary and Quaternary deposits. The highly condensed brines were found in the Triassic rocks at depth of 850 m. Younger aquifers contain great resources of fresh waters of high utilizable value and from so called "Gdańsk aquifer system". It is limited to area of the Upper Cretaceous arthesian basin and covers an area of about 4000 square kilometres. Water concentrates here in fine glauconitic sands (Fig. 2). The Quaternary aquifer expands in the deposits of Vistula River delta, backshore terrace and Reda River paleovalley (Fig. 3). The regional, intermediate and local underground water flows are distinguished within the Gdansk aquifer system (Fig. 1). The feeding area for all aquifers is the morphologicaly diversified upland of Kaszuby Lake district. The drainage acts in the seaside lowland belt, fringing the Vistula River delta and under bottom of the Gdańsk Bay. Waters in the Cretaceous and Quaternary aquifers are profoundly exploited. Their consumption for Gdańsk and Gdynia cities is fixed at about 350000 m3/day and made directions. It impended over quality and amount of waters and reflects in growing saltness of aquifers by saline surface waters, intruding mainly along the Dead Vistula River riversides. The advenced urbanization and factries make possibilities to polute the aquifers from surface. The protection of seaside lowland waters, poorly isolated from surface, is difficult and often impossible. In such situation increases importance of the Kaszuby Lake district, which could be in future the main water feeder for groundwaters of the Gdańsk region.