Abstract This paper presents a water distribution system expansion and operation methodology employing population-based optimization algorithms applied to the Battle of Background Leakage Assessment for Water Networks competition. The problem is formulated as constrained single and multiple-objective optimization problems and implemented in a generic hydraulic optimization and benchmarking software application (Acquamark). To accelerate the evaluation of potential solutions, a distributed computing approach is employed, where necessary, to permit multiple solutions to be executed and evaluated in parallel. A pressure-driven demand extension to the EPANET hydraulic model is also employed to assist the optimization techniques in accurately ranking near-feasible solutions and to dynamically allocate leakage demand to the end nodes of each pipe.