There is no common agreement on the use of balance valves in the most popular variable water flow systems. A comprehensive theoretical analysis has been conducted to investigate the impacts of balance valves on initial cost, pump operation power and system control performance. The investigation finds that eliminating balance valves can (i) reduce by 20-40% pump energy consumption in a typical variable flow water system, (ii) reduce the maximum pressure drop across control valves, and (iii) improve pump efficiency at most partial load conditions. The reduced pressure drops across control valves improve system control performance and may allow selecting some control valves at lower close-off pressures. Consequently, eliminating balancing valves can also potentially reduce system initial cost.