Sediment erosion in guide vane of Francis turbine has been a crucial issue for turbines operating in Himalayas. Large sediment load with higher percentage of Quartz in Himalayan river causes erosion on GV faces, leaf, stem, leading and trailing edges and at clearance gaps (both facing plate and GV edges). This in turn increases profile roughness and clearance gaps height, causing higher friction losses and cross flow across the vanes, which ultimately affects inlet flow dynamics. Research attempts are limited to computational analysis and prediction of erosion losses. The effect of erosion on flow passing vanes is a crucial issue yet to be explored. This work focuses on experimental prediction of effect of erosion in 3 GV cascade system. The cascade geometry was developed with CFD based iterative method, maintaining flow similarity around GV in turbine and cascade. It has been found that the pressure on two sides of vane and at vane outlet increases with erosion for considered extent erosion. (C) 2019 Elsevier Ltd. All rights reserved.