Optimization techniques play an important role in structural design, the very purpose of which is to find the best ways so that a designer or a decision maker can derive a maximum benefit from the available resources. In this thesis optimization techniques may be effective in finding best modeling and shape in reinforced concrete reservoirs (named as RCR) to improve their durability, mechanical behavior, particularly avoiding or reducing the bending moments in these structures. RCR are one of the major structures applied for reserving any kinds of fluids to be used in the different networks. Usually, these structures have fixed shapes which design and analysis based on input discharge, conditions of structure topology and place geotechnical with various combinations of static and dynamic loads. By this concept and effecting project delivery system (PDS) in whole construction of RCR we will decrease at least 14% intensity of mentioned items in total cost of RCR projects.