AWWA ACE95115

Contrary to accepted practice, the deliberate rehabilitation and replacement of distribution system infrastructure is key to continued service, water quality, and prudent fiscal practices. The reinvestment of capital resources to this end are predicated on the practice of sound planning. In practice, such infrastructure renewal will also reduce distribution system maintenance, improve hydraulic capacity and flows available for fire protection and reduce overall system problems. This paper covers the decision making that an infrastructure renewal plan counts on and discusses four types of modeling. These are: predictive modeling to provide the analysis of facility characteristics; geographic modeling to incorporate factors due to the layout and hydraulics of the system; evaluative modeling to combine intangible factors with predicted and geographic factors; and financial modeling to optimize the allocation of existing funds and support the justification of any increases in future spending. Since almost all distribution systems are made up of several vintages and types of parts which are directly related to a particular part of the system based on when it was developed, it is safe to assume that all of the facilities from a given vintage will behave similarly in its "wear." Although applicable to all of the facilities that make up a distribution system including pump stations and valves, etc. for the purposes of maximizing system viability, considering just the mains in this process is sufficient.