According to Sacramento utility officials, over 3.3 million gallons of water were lost last year due to leakages from the city’s water system.
The city has no way of reliably estimating exactly how much water has been lost because 126,000 residential connections have no meters that indicate water usage.
Rob Roscoe, general manager of the Sacramento Suburban Water District, admitted to The Sacramento Bee, “We don’t know if we’re over 10 percent. We could be. We could be at 1 percent. I don’t think so because we’ve got a lot of old mains. The point is, we don’t know exactly where we are until we’re fully metered.” In Roscoe’s district, roughly 25% of 46,112 connections are not metered.
By comparing the total water derived from rivers and aquifers to the records from meters around the area, Brett Ewart, a senior engineer at Sacramento’s water utility, estimated that the city lost between 9 and 11 percent of its water this year.
The American Water Works Association, which states that utilities should not use the terms “unaccounted-for” water and “unaccounted-for water percentage,” but rather, “Non-revenue” Water, explains: “Non-revenue Water however, is specifically defined as the sum of Unbilled Authorized Consumption (water for firefighting, flushing, etc.) plus Apparent Losses (customer meter inaccuracies, unauthorized consumption and systematic data handling errors) plus Real Losses (system leakage and storage tank overflows). In this way, the term “Non-revenue.”
The association says utilities should keep water loss under 10 percent.
In 2014, the California Public Utilities Commission asked nine water utilities representing 96 percent of California customers how much water they had lost; the answers ranged from 2 and 7 percent, averaging 5 percent.
Madelyn Glickfield, director of the Water Resources Working Group at UCLA, expressed skepticism regarding the numbers given by the state’s utilities, pointing out that Israel, which must conserve water, uses far more sophisticated leak-detection technology but typically reports losses of 10 percent or more.
Senate Bill 555, being considered in the state legislature, would force utilities to audit their water losses annually and publish the results on the Internet.
Water loss is a huge problem in municipal systems across California–one that has become more acute as the drought has limited water supplies more and more.