Assessing Data Adequacy for Determining Utility-Specific Water Loss Reduction Standards

Abstract

In 2017, urban water retailers in California reported 364 million m3 in real water losses within their distribution systems, representing on average 7.12% of their total water delivered that year. Recognizing the value of these water losses, the California State Water Resource Control Board (SWRCB) has proposed setting economic water loss reduction standards—regulatory water loss levels—that are individually tailored based on utility-specific data. Our research analyzed data sets currently available to the SWRCB, including water audits and electronic annual reports, as well as supplemental data collected by utilities to determine if the information currently available is adequate for creating individually tailored water loss reduction regulations. Adequacy was evaluated based on the data’s completeness, validity scores, and consistency. We found that, given the current state of the data, the resulting standards may not be representative of individual utilities and that annual data variability may be greater than a proposed reduction. It is recommended that entities considering similar individual water loss reduction targets consider timing, the data collection tool, and data selection when developing utility-specific real loss reduction policy.