This paper deals with flow field and sediment flux measurements at alpine desanding facilities. 3D flow velocities, turbidity, density and water temperature were recorded and water samples were taken in the field. The samples were evaluated regarding suspended sediment concentration (SSC) and particle size distribution (PSD) in the laboratory. SSC was correlated with turbidity. Results are presented for the facility Saas Balen, affiliated with the hydroelectric power plant Ackersand I. The applied instrumentation and utilized methods were proven to be appropriate to assess flow field and sediment fluxes. The flow field is inhomogeneous in large parts of the basin. The presence of tranquilizing racks influences the flow significantly. Reliable correlations were found for SSC and turbidity. PSD revealed a refinement of the mean particle size. The mass-related trapping efficiency of the desanding facility was estimated based on calculated sediment fluxes.