This paper presents a general overview of a high-rate sedimentation technology, the GEWE Lamella System. In particular, aspects of the hydraulic flow in the sedimentation basin are reviewed. Separation of suspended solids from a liquid by gravity (sedimentation) is largely a function of the size of the available sedimentation area. Installing parallel plates (lamella) on a slight angle increases the sedimentation area. The separated particles settled on the plates slide down and fall into the sludge space below the plates. The GEWE system was developed primarily to separate light and sensitive hydroxide flocs. Special attention was given to hydraulic flow within the basin. This article offers some background on plate settlers and discusses operating parameters for the GEWE system.