A THESIS SUBMITTED TO THE DEPARTMENT OF WATER RESOURCE AND IRRIGATION ENGINEERING, INSTITUTE OF TECHNOLOGY, SCHOOL OF GRADUATE STUDIES, ARBAMINICH UNIVERSITY IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN IRRIGATION AND DRAINAGE ENGINEERING

Abstract

In water resource planning and management reservoir operation by using the application of simulation models is an important ways of analyzing water resources system. HEC-ResSim is one of the simulation models that possess of arrange of reservoir simulators and can simulate water resources systems. In this research, operational analysis of Legemera earth dam reservoir was done. Reservoir performance evaluation also done based on standard operating policy water release method. With this method Reliability, resiliency and vulnerability indices were used for system evaluation. Legemera earth dam reservoir water balance was simulated by considering project expansion alternatives. Irrigation water requirement of the study area was determined using FAO CROPWAT model. By introducing the system expansion, increasing command area from 170 to 200ha and also 230ha, failures in the system were increased 13.23 % and resilience was decreased from 36 % for alt.1 to 30%.for alt.3.With HEC-ResSim model simulation, optimal reservoir storage level throughout the simulation period was set at 2451.64 m.a.s.l and annual maximum and minimum water level were set at 2455.24 m.a.s.l and 2445 m.a.s.l respectively. According to this value rule curve was prepared. Based on the findings, conclusions and recommendations for further studies were drawn