One of the crucial and challenging issue with the use of Wireless Sensor Network (WSN) for monitoring pipelines, detecting and locating leaks is that of energy saving. With the use of real-time acquisition using heterogeneous sensors, communication and innetwork processing, a great level of accuracy in the results can be achieved, but may involve huge energy consumption. In this work, the idea of exploiting 3 different approaches for energy conservation in WSN is presented for water pipelines monitoring namely schemes based on Duty-Cycling and Data-Driven approaches for energy saving, and Least Squares Estimation are presented for reducing communication, sensing and processing energies, when noisy pressure sensors along a straight pipeline are used for finding the location of a leak. Simulation results are shown for localization of small and large leaks for different numbers of sensors that result in various levels of accuracies and energy consumption, which shed some light on the tradeoff that can be achieved in saving energy and attaining good accuracy.