We show that an inhomogeneous spin-orbit-coupled system supports bulk manifestations of the spin Hall effect, and we develop a theory of this phenomenon in the framework of the spin diffusion equation formalism. In the presence of a spin-density wave with wave vector perpendicular to an applied electric field, an anomalous charge-density wave, characterized by a pi/2-phase shift and a nonmonotonic time-varying amplitude, is induced away from the sample boundaries. The optimal conditions for observing the effect are determined.