Analyses of the pipeline diameters and associated lengths from the 141 WDSs were used to determine typical pipeline diameter distributions. Firstly, the WDSs were classified into different area size and topography categories, as defined in Table 7. Apart from the categorisation as per Table 7, the WDSs were also classified as General Residential or Low-Income Residential. It is noted that some overlap existed between the area size and the area topography. For example, an area could be classified as both small and hilly. Moreover, a flat area could be classified as either General Residential or Low-Income Residential. The diameter distributions were obtained by determining the average diameter distribution by overall pipeline length within categories of WDSs with similar characteristics. The final distributions are presented in the Results section.