The pH, δ13C of total dissolved carbon and HCO3, Ca2+, Ca2+ + Mg2+ contents in spring waters were investigated. Changes of these values were recorded for 8 months of 1982 and 1983. The changes were irregular and larger in winter and early spring, than in autumn and late spring. These changes and a longterm trend observed in October and November are discussed in terms of models of Deines et al. (1974) and the theory of mixing of waters (Wigley and Plummer 1976).