  In this article we develop a theoretical framework to study the hydrodynamic
interactions in the presence of a non-flat and no-slip boundary. We calculate
the influence of a small amplitude and sinusoidal deformations of a boundary
wall in the self mobility and the two body hydrodynamic interactions for
spherical particles. We show that the surface roughness enhances the self
mobility of a sphere in a way that, for motion in front of a local hump of the
surface, the mobility strength decreases while it increases for the motion
above a local deep of the rough surface. The influence of the surface roughness
in the two body hydrodynamic interactions is also analyzed numerically.
