We consider the use of a novel load balancing-aware routing algorithm for multipath wireless sensor networks. Focusing on solutions that minimize end-to-end delay, we optimize resource usage in mobile nodes. An analytical model is provided for flow-level multipath routing design; we then proceed to simplify the model for more practicality while retaining much of the original functionality. The practical system incorporates a load balancing-aware feedback control system based on the analytical model, allowing us to optimize traffic flow through the system. The proposed network design results in significant improvement in system delay and offered load.