ABSTRACT: In the contribution hydrogeological disturbing of the temperature and hydrochemical field in the area of Gabčíkovo is evaluated. Disturbing is caused by an extensive reserwoir of shallow cold groundwaters. The thermal field is distinctly disturbed to depth of 2000 m, less distinctly to depth of 3000 m. To the contrary this reservoir of cold waters had favourable influence chemism of geothermal waters in the part underlying it.