Analyzing Critical Elements in US Water Systems Using Hydraulic Modeling Coupled with GIS

According to the most recent Drinking Water Needs Infrastructure Survey conducted by the United States Environmental Protection Agency (EPA), the US will need to invest $83 billion over the next 20 years to repair/replace deteriorating water distribution infrastructure. There is almost 1 million miles of distribution piping in the United States, the majority of which will be reaching the end of their life spans in the next 30 years (WSTB, 2005). Network reliability has become a major issue. Determining the location of these critical elements (aged valves, old pipes, etc.) and what would happen if they failed is an important part of replacing/refurbishing strategies of any water utility. There are different methodologies and technologies used for identifying the location of these critical elements and rating the impact of their failure. There are also some new advances in hydraulic modeling and GIS software that allow municipalities/utilities to use their hydraulic models along with their GIS as a cost-effective tool for analyzing pipe/valve failures and replacement strategies in their water distribution system. Some of the new technologies present in hydraulic modeling software allow users to analyze element criticality in water distribution systems to further look at system failures, network outages, and contamination. This technology proves extremely useful, but there is still a need to be able to couple this technology with GIS to further identify and quantify critical elements in terms of spatially analyzing leakage and the direct affect on customers. This paper will discuss the current methodology of criticality analysis and the procedures for tying in GIS data to further maximize the return on investment for maintaining key infrastructure assets. It will highlight a case study that proves that this methodology is useful and quite straightforward to implement in any water system that utilizes or plans to utilize a hydraulic model.