The　Schur　complement　domain　decomposition　method　is　used　for　solution　of　large　linear　systems.　The　algorithm　is　based　on　the　subdivision　of　the　domain　into　smaller　ones　and　the　solution　of　those　sub-domains　independently.　Regarding　water　distribution　systems　modeling,　the　hydraulic　simulation　could　be　formulated　as　a　sequence　of　systems　of　linear　equations.　Therefore,　this　paper　utilizes　the　domain　decomposition　method　to　accelerate　the　simulation　process　further.　The　method　is　evaluated　using　a　large　scale　real-world　system　with　63,616　junctions　and　64,200　pipes　as　case　study.　The　case　study　shows　that　the　methodology　could　improve　the　performance　of　hydraulic　simulation　app.　by　a　factor　of　8　without　losing　accuracy　at　a　suitable　level　of　domain　decomposition.　Although　the　optimal　level　of　decomposition　is　case　specific,　considerable　speedup　might　still　be　achievable　by　decomposing　a　large　system　into　only　a　few　subsystems.　(C)　2013　Elsevier　Ltd.　All　rights　reserved.