From the Directors...
How to Capture Revenue From Low-Flow Consumption
In recent decades, the improvements in plumbing fixtures, conservation, reuse and urbanization have resulted in a significant reduction in per capita usage of potable water within the U.S. (U.S. Geological Survey, Estimated Use of Water in the United States in 2015, Circular 1441). This has benefits and consequences.
A reduction in usage is a welcomed relief for water stress and sustainability—but other factors continue to create strain in the water cycle and long-term sustainability. At the same time, the reduction in usage also creates financial stress on water utilities and cities as costs continue to rise. With per-capita usage declining and costs increasing, the ability to amortize costs across unit sales becomes more complicated—which in turn raises the overall unit costs. This makes the accuracy and completeness of the overall consumption measurement more important than ever.
One contributing factor to reduced consumption is the cumulative usage of low-flow fixtures. According to a Water Research Foundation study presented at AWWA's North American Water Loss Conference, residential usage has increased 37% and 178% in the 0...0.25 and 0.25...1 gpm flow ranges respectively between 1999 and 2016. The study also showed that 11.5% of total residential usage is in the 0...0.25 gpm flow range.
Historically, mechanical meters started to measure flow at 0.125...0.25 gpm, and accuracy was less than the typical ±1.5% at normal flow ranges. But with our E-Series® Ultrasonic meters, flow can be measured as low as 0.04 gpm and normal flow accuracies at 0.08 gpm. This means as much as 30-60% more low-flow consumption is captured with E-Series Ultrasonic meters.
Consider a typical residential service with a consumption of 4,000 gallons per month. The annual usage would be 48,000 gallons. If 11.5% of total usage is in the low-flow range (0...0.25 gpm), the low-flow component represents 5,520 gallons. At an average value of $10 per 1,000 gallons (potable water and wastewater), this represents $55.20 per year. If 30-60% more of the low-flow component is captured, the additional return on investment with E-Series Ultrasonic meters for just the low-flow component is between $16.56 and $33.12 per year. Over 20 years, this would be between $331.20 and $662.40 of additional revenue to the water utility or city per service.
Specific usage and rates may vary by utility and service connection—but the opportunity for increased revenue remains.