When pump-dredged clays are discharged into a disposal pond in the sea, soil particles are initially suspending in the water and gradually settles to the sea bottom. According to subsequent discharging, a new sediment is piled on the top surface of the sediment already formed, and the sediment already formed consolidate due to the own weight of new one over a long period of time. To predict the capacity of such disposal pond, it is important to estimate the time-dependent volume change of dredged clays during the reclamation process. In order to estimate the high accuracy the time when the current disposal pond will be full, it is necessary to use the reclamation analysis developed based on a general consolidation theory. In this paper, targeting the S-3 area of Shinmoji-Oki disposal pond project currently underway, we assume that the model of dredged clay deposited in the future on the ground model can be identified by back analysis. Predictive analysis is performed using consolidation parameters assumed from the physical properties of the collected clay, and different filling periods are confirmed due to differences in the physical properties. Furthermore, we also propose a method to improve the prediction accuracy.