In the title compound, C(19)H(22)BrNO(6)S·H(2)O, the dihedral angle between the planes of the two benzene rings is 3.1 (1)°. These rings are stacked over one another with their centroids separated by 3.769 (2) Å, indicating weak π-π inter-actions. In the crystal structure, mol-ecules are linked by O-H⋯O and O-H⋯(O,O) hydrogen bonds involving the water mol-ecule, forming a two-dimensional network parallel to (001).