Abstract
This research focuses on the best hydrological routing technique of Shiroro Reservoir using Hydrological Engineering Center- Reservoir System Simulation (HEC-ResSim) software. Topographic map and Hydrological data which include elevation, storage, inflow and outflow for 10 peak flood years of Shiroro Hydropower was used in HEC-ResSim for hydrological modelling using Muskingum (Mk), Modified Puls(Mp) and Working Storage and Discharge(Rd) routing methods. Afterwards statistical analysis which included minimum, maximum, mean, variance, standard deviation, analysis of variance, standard error, and coefficient of correlation were carried out to identify the optimal routing method. The overall discharge peaks were 600m3/s, 654.72, 658m3/s and 724.38 m3/s for modified puls, Muskingum, observed (Ob) and working storage and discharge respectively. The correlation coefficient were 0.56, 0.78, 0.81, 0.06, 0.09, 0.42 for Mk and Mp, Mk and Ob, Mp and Rd, Ob and Rd, Mk and Rd and Mp and Ob respectively Mp and Rd had the best relationship of 0.81 and Ob and Rd had the least relationship of 0.06, Rd has the highest standard error of 11.79% and Muskingum has the least as 2.35%. The study recommended digital data acquisition for quality and reliable data and that modified puls routing technique should be adopted for Shiroro reservoir because it maintained optimal discharge value of 600m3/s throughout the flood event.

Key words: Key Words: HEC-ResSim, Hydrological routing, Reservoir Operation and management