Routing plays an important role in energy constrained Wireless Sensor Networks (WSNs). To conserve energy in WSN, energy-efficiency of the routing protocol is an important design consideration. These protocols should maximize network lifetime and minimize energy consumption. In this thesis, a novel multipath routing protocol is proposed for WSNs, which constructs multiple paths based on residual energy of the nodes. The protocol allows the source node to select a path for data transmission from the set of discovered multiple paths based on cumulative residual energy or variance. Choosing a next-hop node based on energy, and using an alternative path for routing achieves load balancing. The results show that the proposed algorithm M-VAR has lower residual energy variance (96%, 90%, 72%, 12% less) and longer network lifetime (404%, 205%, 115%, 10%) than basic Directed Diffusion, load-balanced Directed Diffusion (LBDD-ED-RD), multipath Directed Diffusion (MDD-CRE), and the proposed algorithm M-CRE, respectively.