Parallel Harmony Search (PHS) is a harmony search variant that employs parallel computing approach for improving the final solution quality of harmony search. A preliminary version of PHS was introduced in 2015 and applied to a highly nonlinear water infrastructure planning problem with extreme dimensionality. The application results showed that the PHS was promising and efficient in finding a feasible and near-optimal solution for such problem. However, sensitivity analysis on migration parameters of PHS should be performed to guarantee the best performance of PHS. Migration parameters of interest are migration frequency, migration topology, migration size, and so forth. In this study, PHSs with different migration frequencies are compared with respect to the final solution quality to identify the most efficient frequency in the water infrastructure planning problem.