In wireless sensor networks, data preservation has become a key challenging problem. Data generated by some sensor nodes is huge and due to limited storage space in a sensor node, the data generating nodes have to offload the data to nodes with available storage space and high battery power. The data needs to be preserved in these nodes until the base station collect it. In this thesis, data preservation problem in sensor networks is modeled as network flow problems and it is solved by using network flow algorithms while considering the specific sensor network parameters such as battery power and storage capacity of sensor nodes. The load‐balancing data preservation algorithm maximizes the minimum energy left among the nodes that store data and minimizes the total cost for data redistribution. We also formulated the data‐preserving problem, with limited battery power in each node and minimized the total energy consumption of data preservation. In addition, we also studied and analyzed the feasibility of data preservation when each node has limited battery power.