Suspended particles in treated water accumulate in water distribution pipes and cause discolouration of tap water by resuspension due to hydraulic disturbance. This study aimed to model particle accumulation in drinking water distribution system and compare different countermeasure for managing accumulation process. A simple, empirical model for particle accumulation with water velocity as the main parameter was developed based on lab-scale adhesion experiment simulating different velocities. Analysis of water samples collected during unidirectional flushing was also conducted and the amount of accumulated matters was estimated to be 0.18-3.0 g/m². These data were utilized for calibration of the accumulation model. The model was then applied to the target distribution network to estimate a distribution of the accumulated matters. The total amount of equilibrium accumulation in the network was calculated to be 23.8 kg. Scenario analysis was also conducted assuming 1) reduction of suspended solids (SS) concentration in treated water, 2) downsizing of distribution pipes to increase water velocity, and 3) regular flushing. The effects of each countermeasure was quantitatively compared and appropriate management strategy was discussed at the viewpoint of inner-pipe environment.