The service life of reinforced concrete constitutes the initiation and propagation period. Accelerated corrosion tests are carried out to obtain results in modelling the Service life of reinforced concrete structures. Its erroneous to undertake a direct linear extrapolation of accelerated test results to real structures in predicting their service life. This research examines the relationship between the result from accelerated corrosion and real reinforced concrete water structures. The physical and chemical properties of the materials used in the study were investigated for compliance for use in reinforced concrete water structures. Concrete of three classes M25, M30 and M35 were used to cast accelerated corrosion test samples. For each class 9 concrete samples of diameter 100 mm, 130 mm and 150mm respectively and 300mm long were prepared. A 10 mm diameter bar, 400 mm long was centrally inserted during casting. After curing the test samples were immersed in a 3.5% solution of sodium chloride solution under 6 V. The accelerated corrosion specimens were monitored for onset of cracks and stopped when the cracks were 0.2 mm in width. Using the accelerated corrosion and real reinforced concrete results, a parametric study of the propagation period was done and a model proposed. From the results the proposed and published propagation period model compares well. The result from accelerated corrosion and real reinforced concrete water structures lineally increase for the propagation period. The proposed model can be considered as an input parameter for the service life of actual reinforced concrete water structures and contribute to their optimum performance.