Many water distribution system (WDS) solution methods have been developed to perform demand-driven steady-state analysis. These methods are used to solve the nonlinear system of equations that model a WDS. WDS networks have structural properties that can often be exploited to speed up these solution methods. One solution method that exploits these structural properties is the forest-core partitioning algorithm that was proposed as a preprocessing and postprocessing method that can be used to separate the network into a linear forest component and a nonlinear core component. This paper presents a complementary method for preprocessing and postprocessing called the bridge-block partitioning algorithm (BBPA). This method further partitions the core component of the network into a number of linear bridge components and a number of nonlinear block components. The use of BBPA to partition a WDS network provides significant advantages over current solution methods in terms of both speed and solution reliability.