Using limited data to assess future needs

Abstract

A five‐step methodology was developed to help utilities with sketchy or scarce data on water main break history to budget for future pipe replacement. Most major urban utilities are aware of the need to keep records of distribution system water mains. These records—which typically include data about water main break history, pipe material, pipe vintage, and soil type—are eventually used to allocate budgets to replace, rehabilitate, or repair aging distribution systems. Many utilities have incomplete or scarce water main data, which may make financial planning difficult. Thus, a methodology that facilitates the use of scarce, available data to assess future needs is warranted. Presented is a case study that followed five essential steps: (1) bundle data on water main breaks into homogeneous groups to predict future breaks for water utility regions for which data were insufficient, (2) establish breakage rate patterns for these groups to project future breakage rates, (3) use projected breakage rates to determine the economic life of water mains, (4) examine probabilistic scenarios of water main life, and (5) determine the investments required to replace water mains.