In a field trial conducted in a vineyard on a low-lying hydromorphic soil, it was established that ridging increased the depth from the soil surface to the water table. Ridging did not lower the level of the water table, but increased the soil depth above the water table by the same amount as the thickness of the additional topsoil layer. A good correlation was found between the depth to the water table and the water content of the overlying soil. The distribution of the soil water content with depth varied from a sigmoidal tendency to a virtually linear one as the depth to the water table increased. Ridges of varying width and height did not differ significantly in their ability to improve the internal drainage of the soil. However, during late summer, 600-mm high ridges lost more water through evaporation than 400-mm high ridges of the same width. The problem of higher evaporation caused by the increased soil surface of the higher ridges was overcome by applying supplementary irrigation. Unstable soil that landed on the ridges during the construction process resulted in unnecessary losses of irrigation water due to runoff.