This　paper　aims　to　explore　the　impacts　of　peaking　factors　on　a　water　distribution　system　designed　for　a　small　city　in　Germany　through　model-based　analysis.　As　a　case　study,　the　water　distribution　network　was　modelled　by　EPANET　and　then　two　specific　studies　were　carried　out.　The　first　study　tested　corresponding　system-wide　influences　on　water　age　and　energy　consumption　if　the　peaking　factors　used　at　design　stage　are　inconsistent　with　ones　in　real　situation.　The　second　study　inspected　the　possible　relationship　between　the　choice　of　peaking　factors　and　budgets　by　comparing　several　different　pipe　configurations　of　the　distribution　system,　obtained　according　to　variety　of　peaking　factors.　Given　the　analysis　results,　the　first　study　reveals　that　average　water　age　will　increase　if　peaking　factors　estimated　at　design　stage　are　larger　than　real　values　in　that　specific　system,　and　vice　versa.　In　contrast,　energy　consumption　will　increase　if　peaking　factors　defined　for　system　design　are　smaller　than　ones　in　real　case,　and　vice　versa.　According　to　the　second　study,　it　might　be　possible　to　amplify　peaking　factors　for　design　dramatically　by　a　slight　increase　in　the　investment　on　this　system.　However,　further　study　on　budget　estimation　with　more　factors　and　detailed　information　considered　should　be　carried　out.　©　IWA　Publishing　2010.