Inter-basin water transfers are intended to have a positive impact on the development of a region, but are always accompanied by huge energy consumption. The feasibility and effectiveness of water transfer projects have not yet been clearly evaluated, especially in the light of their energy consumption and effects on social development. This paper develops a method that combines life cycle approach and system dynamic model to reveal the effectiveness of different water supply alternatives (transferred water, reclaimed wastewater and rainwater harvesting) when they are all constrained to consume equal energy. This approach is applied to the case of Jinan city in Shandong province, China, the main water-receiving city on the Eastern Route of the South-to-North Water Transfer Project (ER-SNWTP). The results show that in normal years, Jinan's reclaimed water and rainwater harvesting supply are effective replacements for transferred water under the constraints of equal energy consumption and capital costs; even in dry years these two alternatives still play an important role. The results of this study indicate the relative effectiveness of reclaimed water and rainwater harvesting in supplying urban water while conserving energy and capital.