The corrosion of mild steel as a result of interaction with various types of local natural water samples and distilled water is studied with the help of Mössbauer spectroscopy. The data are supplemented with the studies on IR and magnetic properties as and when required. Distilled water and potable water behave in almost similar fashion wherein ferrihydrite and FeOOH are observed to be the precursors of magnetite, the end corrosion product. In case of brakish water, the additional species, viz., FeCl2, FeOOH and an intermediate possibly FeOCl are accounted, and possible mechanisms are suggested.