A method for making an embankment in areas and forming a barrier against water with the help of supports. For this purpose, corrugated steel sheets or corrugated panels of some other material, such as plastic or aluminum, are folded across their longitudinal direction along perforations in the sheets so that sections of the sheet extend at an angle to one another, and the aforementioned folded formed barrier supports are caused to be positioned on a supporting surface so that a folded section of each sheet forms a barrier support (16) that faces towards the intended damming area. The barrier support is formed laterally by a number of mutually overlapping folded corrugated sheets. An arrangement for the execution of the method.