Water meter degradation can be defined as the need to replace existing water meters with new meters due to under-reporting of actual tenant consumption and lower flow rates associated with the meter types aging. Rapid amortization of the investment is based on the advanced age of the target water meters and the propensity for older meters to degrade over time. Studies date back to 1987 by G.J, Newman, when the water utility industry began to document the susceptibility for older water meters to suffer degraded accuracy and under-reporting of actual consumption.
Water meters are not able to exactly register the total amount of water consumed since they have a limited range of operation. Its performance normally diminishes at low flow rates, which are in most cases due to leaks in the user’s facilities. This problem increases with water meters aging since the accuracy curve decays over time. For instance, a study done by the Water Engineering and Management Journal, explains that meter accuracy degrades rapidly on average after 20 years, falling from a real meter accuracy of 99% down to 82% by year 30. In addition, the size of the meter in relation to aggregate flow-through volume can cause problems, as smaller meters with low flow rates result in the highest degrees of inaccuracy.