A hypothesis was developed that watershed discharge from rainfall, for nonfreezing periods from a tile drained level watershed, was mainly tile flow with negligible amounts of surface runoff and base flow. Daily discharges at the watershed outlet were due to depletion of two parallel linear reservoirs. A fast reacting reservoir, represented by the physical shallow ploughed layer, constituted nearly 40% of the total runoff volume. The slow reacting reservoir, represented by the subsoil zone, contributed nearly 60% of the total runoff volume.