Problems associated with maintaining and replacing water supply distribution systems are reviewed. Some of these problems are associated with public health, economic and spatial development of the community, and costs of repair and replacement of system components. A repair frequency analysis has been completed for distribution system maintenance events (leaks and breaks). The economic implication of various replacement strategies and the effect of water quality (corrosivity) on water loss and system cost are examined. The analysis is based on the data acquired from one large (260 mgd; 11.39 cu m/s) and one smaller (20 mgd; 0.88 cu m/s) water utility. Maintenance costs soon exceed the costs of replacement. Therefore establishing a timely maintenance and replacement program is extremely important from an economic and public health viewpoint.