Document Type : Research Paper


1 Civil Engineering Department, University of Technology, Baghdad, Iraq.

2 Environmental Engineering Department, Tikrit University, Saladin, Tikrit, Iraq.


The issue of time series records containing low inflow than normal, such critical period results in shortage in reservoir storage, thereby reduction in the reservoir's releases that satisfy the demands. When the expected available water is less than the demand, releases may be curtailed, and the reservoir is under stress. This study presents an application of HEC – ResSim model to simulate the operation of Mosul, Dokan Reservoirs, and Samarra Barrage during the dry period 19992000 (modeling of historical data). Simulated results and recorded data were compared in order to, first improve the applicability of the software to simulate reservoir operation by calibrating the model during the period (1990 2000), and the second to identify the similarity and differences between recorded and model result during dry period. The aim of applying this software is to manage the operation of reservoir's system by establishing an operation policy for each reservoir. The simulation plots for Mosul Reservoir, exhibit storage pool elevation within the conservation zone including the ability of release of minimum downstream requirement and the operating Dokan pool reservoir is less than the conservation level. The upstream of Samarra Barrage pool elevation is affected by the look back level with the consideration of normal and minimum operation levels.


  • A new stepped spillway shape was used in experimental work under the skimming flow regime by adding block (tooth) on the step.
  • The tooth-stepped spillway reduces the positive and negative pressure on steps close to the crest by a large amount and especially at high discharge.
  • When the spacing between tooth increase the pressure along the chute will have bad distribution compare to the traditional model.