Primer on Condition Curves for Water Mains - U S Environmental Protection Agency - Bog

The development of economical tools to prioritize pipe renewal based upon structural condition and remaining asset life is essential to effectively manage water infrastructure assets for both large and small diameter pipes. One tool that may facilitate asset management is a condition curve. A condition curve is a graphical representation of the condition of a pipeline versus time. This report provides a review of the state-of-the-technology for structural/physical condition curves for water mains. Various models are summarized such as break frequency curves, deterioration/decay/survival curves, condition rating curves and condition rating indices, and serviceability/performance curves. This report also provides new case study information on how condition curves are used by utilities for managing their water infrastructure based upon a survey of nine utilities. The utilities that were surveyed for these case studies used methods that ranged from very detailed asset management programs that combine inspection, monitoring, and test data with their pipeline condition assessment program to simple analyses of pipe break history to prioritize pipeline renewal activities. The review also discusses short-term and long-term research needs for further development of a performance-based buried infrastructure asset management approach to improve the quality and quantity of data used by all utilities.